Sorry that it may have been unclear - the track day in march was my last track event (gaskets have been done way before, but we removed thermostate during the day).Edgemts said:
Thanks for your help!
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Still overheating
- Thread starter NSX-Racer
- Start date
Thanks for your help!
Well first 103 degrees C equates to around 217 degrees F. That's really not that high when you consider that the boiling temp is 212 degrees F and our system is pressurized.
Secondly the thermostat is there for a number of reasons. First is to get the engine up to it's proper operating temperature as fast as possible and then maintain it. For us in the U.S., it's 190 degrees F when it opens. Second it provides some restriction to the coolant flow so the coolant has enough time to pull heat from the engine into itself and then eventually to the radiator to be cooled by the radiator. Third the restricted flow is needed to make sure that the water pump impellers are always covered in coolant so they don't cavitate and produce bubbles. So keep the thermostat in or at least some form of restriction in the circuit.
I'm not sure if some of you have noticed, but in certain racing circles this problem of over heating was seen to be caused by the pump running too fast and causing cavitation. I have seen pumps designed with different shaped impellers and also different pulley sizes to slow them down to prevent cavitation at the higher speeds that these engine are running. Sometimes they do both, depending on how the engine is used, such as drag racers, versus NASCAR, F1 and so on. I mean in F1 can you see how fast a water pump would be spinning at 19,000 RPM these engines are capable of these days. That's why I'm sure they are using electric water pumps to cool those engines as they are in other race engine designs.
So with that and everything else you've done, little has been said about the water pump design and/or speed when the car is always at or near redline under a heavy acceleration load for long periods of time. Has anyone looked in this area? What did Comptech do for the Spice Acura? Maybe you should email them about this to see what they have done to solve the problem. How about P.D. Cunningham's Real Time racing NSX. How did they solve the problem? They were even supercharged and that produces even more heat for the engine. I know an oil cooler is a must for a race car, but is that all you would need?
One final factor is that if you're going to track this car even on a part time basis, then get good gauges that are accurate and react quickly to the key things you need to know. Water temp; oil temp; oil pressure; are just the minimum. I do know from my car that when my stock oil pressure gauge reads about 2 1/2 marks during full Vtec, my aftermarket gauge is reading 52 psi and no lower even while my oil temp is reading above 235 degrees F. During normal driving the oil pressure is 80 psi with a spurt to 90 until the pressure relief valve kicks in and drops it back to 80. I've got a second tap on the oil block so I can have both a stock and aftermarket oil PSI gauge. If one goes dead, I can quickly see if the other one is showing pressure or not.
Good luck on this one. It looks like a long process you've been going through.
Secondly the thermostat is there for a number of reasons. First is to get the engine up to it's proper operating temperature as fast as possible and then maintain it. For us in the U.S., it's 190 degrees F when it opens. Second it provides some restriction to the coolant flow so the coolant has enough time to pull heat from the engine into itself and then eventually to the radiator to be cooled by the radiator. Third the restricted flow is needed to make sure that the water pump impellers are always covered in coolant so they don't cavitate and produce bubbles. So keep the thermostat in or at least some form of restriction in the circuit.
I'm not sure if some of you have noticed, but in certain racing circles this problem of over heating was seen to be caused by the pump running too fast and causing cavitation. I have seen pumps designed with different shaped impellers and also different pulley sizes to slow them down to prevent cavitation at the higher speeds that these engine are running. Sometimes they do both, depending on how the engine is used, such as drag racers, versus NASCAR, F1 and so on. I mean in F1 can you see how fast a water pump would be spinning at 19,000 RPM these engines are capable of these days. That's why I'm sure they are using electric water pumps to cool those engines as they are in other race engine designs.
So with that and everything else you've done, little has been said about the water pump design and/or speed when the car is always at or near redline under a heavy acceleration load for long periods of time. Has anyone looked in this area? What did Comptech do for the Spice Acura? Maybe you should email them about this to see what they have done to solve the problem. How about P.D. Cunningham's Real Time racing NSX. How did they solve the problem? They were even supercharged and that produces even more heat for the engine. I know an oil cooler is a must for a race car, but is that all you would need?
One final factor is that if you're going to track this car even on a part time basis, then get good gauges that are accurate and react quickly to the key things you need to know. Water temp; oil temp; oil pressure; are just the minimum. I do know from my car that when my stock oil pressure gauge reads about 2 1/2 marks during full Vtec, my aftermarket gauge is reading 52 psi and no lower even while my oil temp is reading above 235 degrees F. During normal driving the oil pressure is 80 psi with a spurt to 90 until the pressure relief valve kicks in and drops it back to 80. I've got a second tap on the oil block so I can have both a stock and aftermarket oil PSI gauge. If one goes dead, I can quickly see if the other one is showing pressure or not.
Good luck on this one. It looks like a long process you've been going through.
ATERPAK said:
A couple more questions...
1. is the car over heating while idling & not moving?
2. are the main coolant lines that run off the thermostat housing FIRM (as firm as an apple) when the car is at these temps?
Cheers,
-- Chris
1. is the car over heating while idling & not moving?
2. are the main coolant lines that run off the thermostat housing FIRM (as firm as an apple) when the car is at these temps?
Cheers,
-- Chris
Chris:
1. No, it doesn't overheat in that condition or in any other that may appear during normal street use. We could never repeat the problem outside the track or dyno.
2. Does "firm" means hard or tough? You talk about the rubber lines in the engine compartment? I didn't check it, what's your suspicion?
all in all I suspect this to be an anormality because I tracked the car for years without that problem but I can't recall exactly if it started after a certain event or modification - there were always too many variables that may have lead me to the wrong clues (just like the bent lamelles on the old stock radiator or a stone guard with not enough airflow or extremely high ambient temps or the bad head gaskets, or, or). No matter what we changed or cured it always turned out the same - really desperates me.
1. No, it doesn't overheat in that condition or in any other that may appear during normal street use. We could never repeat the problem outside the track or dyno.
2. Does "firm" means hard or tough? You talk about the rubber lines in the engine compartment? I didn't check it, what's your suspicion?
all in all I suspect this to be an anormality because I tracked the car for years without that problem but I can't recall exactly if it started after a certain event or modification - there were always too many variables that may have lead me to the wrong clues (just like the bent lamelles on the old stock radiator or a stone guard with not enough airflow or extremely high ambient temps or the bad head gaskets, or, or). No matter what we changed or cured it always turned out the same - really desperates me.
Another update: 2nd dyno run showed no overheating, the additional oil cooler with another thermostate seemed to decrease the temperature significantly.
But: Peak hp was only 270 PS, one of the O2 sensors showed no data and the engine seems to run lean which may also cause overheating. Although there was no CEL the sensors will be changed and there will be another dyno run (and I will remount the water thermostate in the engine bay before).
If I really had only 270 PS the last time at Hockenheim that would be a wonderful excuse for my worse laptime :wink: I would have suspected something about 290 without cats and A/C compressor.
But: Peak hp was only 270 PS, one of the O2 sensors showed no data and the engine seems to run lean which may also cause overheating. Although there was no CEL the sensors will be changed and there will be another dyno run (and I will remount the water thermostate in the engine bay before).
If I really had only 270 PS the last time at Hockenheim that would be a wonderful excuse for my worse laptime :wink: I would have suspected something about 290 without cats and A/C compressor.
Sorry, if I bore you to death, but here's the next update after dyno day 3:
O 2 sensor was changed, but made no remarkable change overall, engine dynoed with 272 PS - still too low. Good news: Once again no overheating.
During and between the dyno runs my techie checked nearly everything: Timing, timing belt compression, leaks, sensor data etc. - everything was okay with one exception: The cam of the rear cylinder bank does not change to the "sharper" profile to full extend at the Vtec point (i hope you know what I mean). It seems that the Vtec system lacks of oil pressure here while it's okay for the front cylinder bank. Of course that reduces overall power.
Now while I write this my techie inspects every little part of the system (electronical, mechanical and hydraulic), changes gaskets, lines etc., also valves if necessary - strictly after the service manual advices. That way he now learns all he needs to know about the details of the Vtec system - good side effect :wink:
Don't forget: We have no Mark Basch or Bridgewater Acura here - I guess my (non Honda-)techie has already become the best NSX expert in a 100-miles-circle or maybe more in the last 6 years he worked on my car. There is only a handful Honda dealers in whole Germany that ever had a NSX in their shops.
Next week there will be at least one more dyno day (or whatever it takes to get things working) with the new parts and I still hope for about 290 PS and more.
Any thoughts or experiences on this weird Vtec problem here?
O 2 sensor was changed, but made no remarkable change overall, engine dynoed with 272 PS - still too low. Good news: Once again no overheating.
During and between the dyno runs my techie checked nearly everything: Timing, timing belt compression, leaks, sensor data etc. - everything was okay with one exception: The cam of the rear cylinder bank does not change to the "sharper" profile to full extend at the Vtec point (i hope you know what I mean). It seems that the Vtec system lacks of oil pressure here while it's okay for the front cylinder bank. Of course that reduces overall power.
Now while I write this my techie inspects every little part of the system (electronical, mechanical and hydraulic), changes gaskets, lines etc., also valves if necessary - strictly after the service manual advices. That way he now learns all he needs to know about the details of the Vtec system - good side effect :wink:
Don't forget: We have no Mark Basch or Bridgewater Acura here - I guess my (non Honda-)techie has already become the best NSX expert in a 100-miles-circle or maybe more in the last 6 years he worked on my car. There is only a handful Honda dealers in whole Germany that ever had a NSX in their shops.
Next week there will be at least one more dyno day (or whatever it takes to get things working) with the new parts and I still hope for about 290 PS and more.
Any thoughts or experiences on this weird Vtec problem here?
vtec is a simple pressure switch that pushes a tiny rod to lock the rocker arms.
Are you saying that the rear bank isn't switching?
Check the pressure switch and solenoid?
x
Are you saying that the rear bank isn't switching?
Check the pressure switch and solenoid?
x
NSX-Racer said:
How was this determined? The single wire sensor above the actual spooll valve detects sufficient pressure to operate V-Tech. Lack of pressure has to trigger a cel. I am curious- you say an O2 had no data stream, yet no cel. Now, no V-Tech pressure, still no cel. Have you verified that the cel works?
What mods do you have? (sorry, I have not read all 57 posts)
MB
As I wrote the rear cam didn't switch to it's full extend but it did switch. That's at least what my techie told me, I don't know how he determined that. No CEL AFAIK. Mark, I have no engine mods besides the cat replacement pipes and the K&N OEM replacement air filter (dyno runs were made without filter).
So I guess the sensor (is that what VBNSX calls "solenoid"?) for the Vtec switch does work (therefor no CEL) but there may be a problem afterwards (the spool valve (is that what VBNSX calls "switch"?) or the lines, maybe some oil coal?) that reduces the oil pressure.
A asked again for that old O2 sensor and it seems that there was some data but different from the other densor - not sure if that would trigger a CEL. So I don't think CEL itself doesn't work but that's just a guess, we will check. Anyhow: These sensors seem to be sorted out as a problem.
So I guess the sensor (is that what VBNSX calls "solenoid"?) for the Vtec switch does work (therefor no CEL) but there may be a problem afterwards (the spool valve (is that what VBNSX calls "switch"?) or the lines, maybe some oil coal?) that reduces the oil pressure.
A asked again for that old O2 sensor and it seems that there was some data but different from the other densor - not sure if that would trigger a CEL. So I don't think CEL itself doesn't work but that's just a guess, we will check. Anyhow: These sensors seem to be sorted out as a problem.
I bet Mark wouldn't mind an all-expenses-paid vacation in Europe...NSX-Racer said:
NSX-Racer said:
The vtech assy at the back of the head consists of two parts- the spool valve (a linear solenoid) which has the two wire conn, and a pressure switch (the one wire connector). The valve opens on a COMMAND from the ecu, based on load and rpm, to operate the vtech. The switch sends a SIGNAL back to the ecu to confirm oil has flowed to the vtech rocker lock pins, and at sufficient pressure to operate v-tech. The ecu can fail to send the command and not set a cel, however if the ecu does send the command, and does not recieve a pressure signal back it has to set a cel (in a nominal system).
And yes, coke deposits or other low mechanical pressire problems can cause that.
Normally, nsxtasy would be correct but my calender is full at the moment. I could be available however the weekend of July 24, IF you are close to Hockenhiem :biggrin: :biggrin: :biggrin:
MB
Thanks for the info, Mark. Guess what, I am close to Hockenheim (about 50 miles or so) and if everything else fails I will buy your time and work! :smile:NSXTech said:
Last edited:
Update No. ?? (I don't know, maybe I call it "Longhorn", service pack 3 :wink: ):
Hoorrray - power has come back, still no overheating (at least on the dyno). After my techie went through some serious surgery of the oil-, timing- and other interiours strictly after the service manual he found some coke (or oil coal) deposits in the oil lines and an improper gasket which seemed to block some of the oil pressure of the Vtec-system for the rear cylinder bank.
After reassembling all parts there was a 4th dyno day now. Result after 4 runs:
average of crank power: 225 kW which is 306 PS. And that was with only 80 km/h fan speed with warm air. Water temp. gauge in the car didn't get higher than about 3/4 of the white zone despite some full load tests. My techie expects about 310 PS with fresh air at track speeds.
(stock 3.2 engine with K&N OEM replacement filter in stock airbox, cat replacement pipes and custom made exhaust, no other engine mods) Just to remind you: The last dyno day with not fully engaging Vtec at rear cylinder bank we had only 272 PS which makes a huge difference.
We are all happy at the moment - but will be much happier after the first real life test which I have to schedule now.
BTW: If you need some refreshment you may use my new radiator fan :wink:
Hoorrray - power has come back, still no overheating (at least on the dyno). After my techie went through some serious surgery of the oil-, timing- and other interiours strictly after the service manual he found some coke (or oil coal) deposits in the oil lines and an improper gasket which seemed to block some of the oil pressure of the Vtec-system for the rear cylinder bank.
After reassembling all parts there was a 4th dyno day now. Result after 4 runs:
average of crank power: 225 kW which is 306 PS. And that was with only 80 km/h fan speed with warm air. Water temp. gauge in the car didn't get higher than about 3/4 of the white zone despite some full load tests. My techie expects about 310 PS with fresh air at track speeds.
(stock 3.2 engine with K&N OEM replacement filter in stock airbox, cat replacement pipes and custom made exhaust, no other engine mods) Just to remind you: The last dyno day with not fully engaging Vtec at rear cylinder bank we had only 272 PS which makes a huge difference.
We are all happy at the moment - but will be much happier after the first real life test which I have to schedule now.
BTW: If you need some refreshment you may use my new radiator fan :wink:
Attachments
The king of diagnosis
Just saw this older answer in the thread and in the light of the newest developments it all makes sense: Apparently you (and the CEL code of the car) were on the right track - the oil pressure was too low to fully activate the Vtec for the rear cylinder bank and that may have caused more than one problem (lack of power is only the obvious). Luckily it wasn't an overall oil pressure problem. Once again: Applause and a big "thank you"! :smile:NSXTech said:
did anyone see that video of the NSX-R running agianst a couple lambos in asia ? after some high speed laps the NSX-R was overheating I thought that was odd at the time but it sounds like its not that uncommon when the car is pushed very hard. I would definately support trying another type/brand of coolant and making damn sure that the air was bled under the engine cover and under the bonnet up front... JZ
Code 22 once again
This weekend I tracked the car again after about 3 months of searching, dynoing and fixing. Conditions were fine to check overheating issues: A lot of sun and over 30 degrees C in the shadow (but there was nearly no shadow on the track so I had about double the temperature in the car. And I needed only about 3 laps to see that we didn't solve this issue as it should.
When the car was warmed up I first was glad to feel more power than before in the high rpm range above 6000 or so, but shortly afterwards I had the CEL once again an the engine went into limp mode, cutting off at about 7000 rpm. At that point the oil temperature (I now have a gauge in the middle console and an additional oil cooler at the front) was at about 80 degrees Celsius and the water temperature was fine too (according to the stock gauge).
I shut down the engine on the straight, restarted it and continued driving. Now the CEL was off but the water temperature went up into the red region and I experienced less power in the upper rpms. Oil temp still was under 100 degrees C. I left the track to check things out in the pitlane and read out the error code. It was once again 22 (still the same that I wrote in the first post of this thread centuries ago) which means Vtec failure front cylinder bank.
Remember: My mechanic had checked and cleaned all the Vtec parts rear and front, replaced the sensors and the car ran fine and without CEL multiple times on the dyno (306 PS, which can not be achieved with unfunctional Vtec). But now we know that we may have more than one problem: Code 22 came up before any overheating, but overheating occured afterwards, so we must have an oil pressure problem and a water temp problem.
My mechanic came to the track, checked all lines, tubes and plugs, did some improvised work with the caps of the radiator and the coolant overflow bottle (don't ask my what he has done exactly, it was some scary work with rubbers seals, small tubes etc.), bleeded the coolant system, checked coolant pressure. Usualy those two caps would have been brandnew because he had ordered them before but both weren't available before the track event. You may have guessed it: The modified old caps seemed to hold the water pressure much better than the unmodified ones so these were apparantly both bad. Water temperature stayed in a reasonable region despite the high ambient temperature but after one hot lap CEL came up again.
Back in the pits we added a Liqui Moly Viscosity stabilisator to the oil and headed out again. This time no CEL but we only had about 5 minutes 'til the end of our run group time. Therefor I couldn't check the progression of the water temp for a longer time (oil temp. didn't exceed 100 degrees C the whole hot day under all conditions).
In the last 30 minutes stint of the day (my mechanic had already left) I did get the CEL and limp mode again multiple times (read out 22 once again afterwards), always restarted the engine and continued driving without overheating for most of the stint. Near the end the water temp. went near the red zone, I reduced maximum rpms to about 6000, water temp. came down and just when I entered the pitlane even the last CEL went out without restarting the engine.
Our thoughts are: We should change to a 20W50 or so race prepped oil because it's "thicker" than the recommended viscosity for the street (oil pump is okay). Oil cooler should move to the rear (right side air duct) with additional fan to maintain maximum air stream to front water radiator (which already has an additional high speed fan in front of it plus the stock fan behind). We should wait for the new caps. We should change the stock radiator fan layout from one big fan to 2 smaller fans (more surface area, just look at your car and you will see that the stock fan works only for a part of the radiator, the rest is covered by black plastic).
Just to be clear: All these issues we had and have are highly unlikely to appear at a non tracked car. We were never able to reconstruct any of these problems with my car outside the track. A german Liqui Moly engineer suspected that an engine with that much track kilometers as mine (125,000 overall, way over 20,000 on tracks without any major overhaul) may need more cooling under track conditions than a new one because of all kinds of age effects.
Real race engines don't run such a long distance - they are overhauled after some events or even replaced or, if the have to run for a long time (like the NSX-R at the 24 hours of Nuerburgring), they get a completely different cooling infrastructure than our stock cars. And even there at the Nordschleife (where cooling is usualy not as critical as on normal tracks) you can see some professional prepped cars with overheating issues sometimes.
As always, I find your comments on NSXPrime more worthy than all suspicions and thoughts of people (although they may be engineers) that don't know much about the NSX.
This weekend I tracked the car again after about 3 months of searching, dynoing and fixing. Conditions were fine to check overheating issues: A lot of sun and over 30 degrees C in the shadow (but there was nearly no shadow on the track so I had about double the temperature in the car. And I needed only about 3 laps to see that we didn't solve this issue as it should.
When the car was warmed up I first was glad to feel more power than before in the high rpm range above 6000 or so, but shortly afterwards I had the CEL once again an the engine went into limp mode, cutting off at about 7000 rpm. At that point the oil temperature (I now have a gauge in the middle console and an additional oil cooler at the front) was at about 80 degrees Celsius and the water temperature was fine too (according to the stock gauge).
I shut down the engine on the straight, restarted it and continued driving. Now the CEL was off but the water temperature went up into the red region and I experienced less power in the upper rpms. Oil temp still was under 100 degrees C. I left the track to check things out in the pitlane and read out the error code. It was once again 22 (still the same that I wrote in the first post of this thread centuries ago) which means Vtec failure front cylinder bank.
Remember: My mechanic had checked and cleaned all the Vtec parts rear and front, replaced the sensors and the car ran fine and without CEL multiple times on the dyno (306 PS, which can not be achieved with unfunctional Vtec). But now we know that we may have more than one problem: Code 22 came up before any overheating, but overheating occured afterwards, so we must have an oil pressure problem and a water temp problem.
My mechanic came to the track, checked all lines, tubes and plugs, did some improvised work with the caps of the radiator and the coolant overflow bottle (don't ask my what he has done exactly, it was some scary work with rubbers seals, small tubes etc.), bleeded the coolant system, checked coolant pressure. Usualy those two caps would have been brandnew because he had ordered them before but both weren't available before the track event. You may have guessed it: The modified old caps seemed to hold the water pressure much better than the unmodified ones so these were apparantly both bad. Water temperature stayed in a reasonable region despite the high ambient temperature but after one hot lap CEL came up again.
Back in the pits we added a Liqui Moly Viscosity stabilisator to the oil and headed out again. This time no CEL but we only had about 5 minutes 'til the end of our run group time. Therefor I couldn't check the progression of the water temp for a longer time (oil temp. didn't exceed 100 degrees C the whole hot day under all conditions).
In the last 30 minutes stint of the day (my mechanic had already left) I did get the CEL and limp mode again multiple times (read out 22 once again afterwards), always restarted the engine and continued driving without overheating for most of the stint. Near the end the water temp. went near the red zone, I reduced maximum rpms to about 6000, water temp. came down and just when I entered the pitlane even the last CEL went out without restarting the engine.
Our thoughts are: We should change to a 20W50 or so race prepped oil because it's "thicker" than the recommended viscosity for the street (oil pump is okay). Oil cooler should move to the rear (right side air duct) with additional fan to maintain maximum air stream to front water radiator (which already has an additional high speed fan in front of it plus the stock fan behind). We should wait for the new caps. We should change the stock radiator fan layout from one big fan to 2 smaller fans (more surface area, just look at your car and you will see that the stock fan works only for a part of the radiator, the rest is covered by black plastic).
Just to be clear: All these issues we had and have are highly unlikely to appear at a non tracked car. We were never able to reconstruct any of these problems with my car outside the track. A german Liqui Moly engineer suspected that an engine with that much track kilometers as mine (125,000 overall, way over 20,000 on tracks without any major overhaul) may need more cooling under track conditions than a new one because of all kinds of age effects.
Real race engines don't run such a long distance - they are overhauled after some events or even replaced or, if the have to run for a long time (like the NSX-R at the 24 hours of Nuerburgring), they get a completely different cooling infrastructure than our stock cars. And even there at the Nordschleife (where cooling is usualy not as critical as on normal tracks) you can see some professional prepped cars with overheating issues sometimes.
As always, I find your comments on NSXPrime more worthy than all suspicions and thoughts of people (although they may be engineers) that don't know much about the NSX.
Hondas are very good about Self Diagnostic codes being closely related to an actual problem, it is setting a code 22 its because the computer is not seeing the Front valve timing oil pressure switch open the curcut when it is suposed to be open, and due to the fact that it does not set this code everytime the motor is run says that more than likely there is not enough oil pressure at that switch when the motor is pushed hard, now this could be caused by eather the spoilvalve not functioning properly or that there just isnt enough oil pressure/volume at the Front head under hard/hot use, this may or may not be related to your overheat but if the front head is not getting the proper volume/pressure of oil its very possible that under load the friction is causing excess heat to build up, I would be curious to see a infered thermometer used on each head directly after track use to see if the front head is notibly warmer than the rear,also you can set up an oil pressure gauge on both heads and than watch them both on the dyno...Just some food for thought...JZ
Thanks for the reply which is about the same as my thoughts. Weired that the spoil valves and oil lines were all checked, cleaned and seemed to work fine. So the question is: Why is there a lack of oil pressure?zahntech said:
What I didn't write is that we applied a digital temperature measure unit during driving with a sensor on top of the front cylinder bank. We mounted the display at the window between passenger and engine compartment so that my mechanic could read it during driving. The temperature didn't exceed 90 degrees C there which was about the same as the oil temperature. Too bad we have no comparison data for the rear bank.
Regarding overheating, I had the problem again the last two days at Thunderhill where the ambient temps were in the mid to high 90F and track temp was as high as 143F (shade was 104F).
Before this track event, I had drained the radiatior from the lower bleed valve and added one gallon of distilled water to make it more like 65/35 mix and already had one bottle of RedLine's wetter. Though it helped a little by only delaying the overheating by one more lap. Al Terpak had the same issue with similar setup. Kip - whose car has an oil cooler was getting some higher reading temps as well but not as high as ours. On the other hand, SMGNSX (Steve Ghent) on this forum had changed all his hoses and was running on 100% distilled water with a bottle of wetter, his temp gauge stayed on the middle - and he was keeping the car in the VTEC most of the time. So perhaps the antifreeze might be the issue.
I also hear rumors of a new racing radiator will become avialable soon :wink:
Before this track event, I had drained the radiatior from the lower bleed valve and added one gallon of distilled water to make it more like 65/35 mix and already had one bottle of RedLine's wetter. Though it helped a little by only delaying the overheating by one more lap. Al Terpak had the same issue with similar setup. Kip - whose car has an oil cooler was getting some higher reading temps as well but not as high as ours. On the other hand, SMGNSX (Steve Ghent) on this forum had changed all his hoses and was running on 100% distilled water with a bottle of wetter, his temp gauge stayed on the middle - and he was keeping the car in the VTEC most of the time. So perhaps the antifreeze might be the issue.
I also hear rumors of a new racing radiator will become avialable soon :wink:
Sorry to hear from another overheating victim. I doubt that the lack of anti freeze would cure your problem - at least it didn't cure mine (okay, maybe that's another story but you never know if there's another hidden problem that causes the overheating).
What really annoys me is that I can't track down the problems to one cause. It's always a second (or third or fourth) bummer that makes me desperate - last fall it was the whole Vtec system that didn't work and increased my laptime on the same track from previous best (under 1:30) to more than 1:34, this year when Vtec seemed to work (only for some laps) I was about 1:31 - I claim that to a lack of peak power because the engine went too hot.
Isn't it annoying when you're ready to attack but the car isn't? That sucks - now for about one year...
What really annoys me is that I can't track down the problems to one cause. It's always a second (or third or fourth) bummer that makes me desperate - last fall it was the whole Vtec system that didn't work and increased my laptime on the same track from previous best (under 1:30) to more than 1:34, this year when Vtec seemed to work (only for some laps) I was about 1:31 - I claim that to a lack of peak power because the engine went too hot.
Isn't it annoying when you're ready to attack but the car isn't? That sucks - now for about one year...
CEL 22 does not indicate a malfunctioning spool valve, but rather a lack of pressure at the pressure switch (see my previous post). There is a pressure test port on each head for testing available and actual Vtech pressure with spool open. I would hook up a pressure guage with whip hose and read it from inside the car while driving, as opposed to on the dyno. This will give you the chance to observe it under actual driving conditions including temperature and (pan) windage conditions. You will also be able to corelate, or prove no corelation between, heat and VTech issues. I know you had the VTech checked and rechecked, but I woonder if the O ring under the oil plate might have been left out.
MB
MB
Hrant said:
Hrant maybe it's time to get one of these bad boys and see what happens. I believe Ponyboy went with this Radiator and it cured his overheating problems. I might just have to get one if my new stock Radiator does not cure my overheating at the track. I wont know until next month... just crossing my fingers it does the trick.
http://www.rondavisradiators.com/new_products.htm
NSX 3.0 said:
Good point. But I am told that the Ron Davis radiator interefers with the Type R brace given the lower positioning of the radiator hose .......... as we solve one problem we seem to encounter another, so much for mother Honda listening to our pleas ...... :wink:
As I said, there is a rumor that a new racing radiator is being developed exclusively for NSX application with proper mounting, fans, shroud, ..... I have no clue what the retail price will be but I am sure it will not be cheap.
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