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Smell rubber burn.

D

drtruong

Experienced Member
Joined
18 July 2008
Messages
1,231
Location
North of CA
Hi guys,

I have supercharger and I have smelled the rubber burn every time I drive it. The rubber burned smell seems to come from the intake after I drive the car. Not sure if it is from the tires or the engine bay. What is the possibility that could have caused the rubber burned smell. Could it be from the clutch? If so, how would I verify it? Thank you
 
Over heated / slipping clutches do not smell like burning rubber. If the clutch is slipping enough to smoke it should be relatively obvious when you are driving the car. You said the smell comes from the intake - do you mean the engine air intake in front of the left rear wheel or the cabin fresh air intake which is up front?

When was the last time your brakes were checked? Any chance you have a really worn pad that has jammed sideways and is dragging on the disk. That usually make a fair amount of noise; but, typically does not smell like burning rubber either - probably more like burning clutch. If you really do have burning rubber that will typically be accompanied by some smoke. Check for that. Also, have a look at the supercharger and alternator drive belts to see if they show signs of slippage.
 
Old Guy said:
Over heated / slipping clutches do not smell like burning rubber. If the clutch is slipping enough to smoke it should be relatively obvious when you are driving the car. You said the smell comes from the intake - do you mean the engine air intake in front of the left rear wheel or the cabin fresh air intake which is up front?

----->The air intake on the back of the driver side.

When was the last time your brakes were checked? Any chance you have a really worn pad that has jammed sideways and is dragging on the disk. That usually make a fair amount of noise; but, typically does not smell like burning rubber either - probably more like burning clutch. If you really do have burning rubber that will typically be accompanied by some smoke. Check for that. Also, have a look at the supercharger and alternator drive belts to see if they show signs of slippage.
Click to expand...

----> brake pads are fine and I don't think the brakes. Only smell burning rubber, but no smoke. If it is the clutch, what might have caused to burn the clutch? getting too old it has only 35K miles.
I will check the belts.

Many thanks guys
 
drtruong said:
----> brake pads are fine and I don't think the brakes. Only smell burning rubber, but no smoke. If it is the clutch, what might have caused to burn the clutch? getting too old it has only 35K miles.
I will check the belts.

Many thanks guys
Click to expand...

The NSX can be a slightly difficult car to drive smoothly. If you rev the engine to about 1500 - 2000 RPM and then slip the clutch to get a smooth lurch free start from a stop sign or a traffic light that will result in extra clutch wear. A lot of stop and go traffic will also result in faster clutch wear. A lot more horsepower than stock (do you have a high boost pulley on the SC?) and regular heavy use of the gas pedal will certainly accelerate wear on an OEM clutch. My 2000 has something over 72,000 miles with an original clutch which is not showing any obvious signs of wear; but, my engine is unmodified.

I still think that if your clutch was slipping enough to generate that wonderful burnt clutch smell, you would be able to tell when driving. When you press down hard on the gas a slipping clutch will allow the engine speed to increase very quickly. If you do pedal to the metal in 1st gear and the tach heads for 8000 RPM right away without the tires breaking loose - that is a slipping clutch.

Don't rely on a belt tension check - check for glazing or damage on the belts which is a sign of slippage. If there is damage, replace and then adjust tension. The other thing is check for a broken rubber hanger on the exhaust system. A broken or slipped hanger touching the exhaust can generate a genuine 'essence of burning tire', particularly if you have an aftermarket exhaust that does not have heat shields. If you lack exhaust heat shields check to see if the heat has cause a piece of undercoating to peel away and drop and stick to the exhaust. That will smell nifty and stick around for a while. In fact, check for anything coming into contact with the exhaust and the catalytic converters. Converters can get super stinky hot, particularly if your fuel mix is running a little to the rich side.
 
CTSC low boost or high boost?

If the smell is from the area around the air filter box it's not the belt. Anyway the belt should be replaced after 5 years or every 10k miles (just my recommendation). Tension: Twist it with your finger and thumb on the left side of the pulley. If the tension if ok you should be able to do that by about 90 degrees.
 
I took the car out again and this is what I experienced. When the car is in 3rd gear with pressing the gas pedal, RPM jumped but lost the power ( CTSC did not kick in for few secs) following the burning rubber smell.

So what is it? My CTSC is fairly new and installed by Driving Ambition. I maybe have put on 3K miles max.
 
goldNSX said:
CTSC low boost or high boost?

If the smell is from the area around the air filter box it's not the belt. Anyway the belt should be replaced after 5 years or every 10k miles (just my recommendation). Tension: Twist it with your finger and thumb on the left side of the pulley. If the tension if ok you should be able to do that by about 90 degrees.
Click to expand...

CTSC not sure what boost that I have. Dyno test shows 352Hp at 7845 RPM and 240lbft at 7845 RPM. I am not a mechanic. sorry
 
have the ctsc drive belt checked for proper alignment. Then check for proper tension, not too much or too little.

I self installed my CTSC, drove it for some +50k miles and never had an issue and never changed the belt.

However, other folks have had issues with belt snapping or coming off, DougHa was always dealing with it.
 
drtruong said:
RPM jumped but lost the power ( CTSC did not kick in for few secs) following the burning rubber smell.
Click to expand...
This points to a slippling clutch. CTSC should kick in immediately, it's no turbo. Take the car to your tech.
 
That's why I've asked about low or high boost. Your system seems to be low boost. So the stock clutch is ok. Not so sure about high boost. I'm on low boost with a new OEM clutch as well and can still smell the clutch - a tiny bit - after some fun pulls but nothing to be worried about.
 
goldNSX said:
That's why I've asked about low or high boost. Your system seems to be low boost. So the stock clutch is ok. Not so sure about high boost. I'm on low boost with a new OEM clutch as well and can still smell the clutch - a tiny bit - after some fun pulls but nothing to be worried about.
Click to expand...

Since I am not a mechanic, the CTSC has to do with wearing out the clutch faster?
 
drtruong said:
Since I am not a mechanic, the CTSC has to do with wearing out the clutch faster?
Click to expand...
Yes, more torque. Maybe your clutch is old or oily (mine was both back then), a failure just shows up a little bit earlier with the CTSC than without.
 
>Acura Dealer and they quoted $6814 to replace the clutch

I think that is the "we don't really want to do the job, but if you pay us enough we will" price.


You do need to do additional testing before getting the parts cannon out.

A complete change out of a NA2 clutch is costly, so it is better to take to an indpendant that doesn't have to adhere to strict dealer guidlines, which can save you a lot of money. On a NA2 you do want to catch a worn clutch before it damages the flywheel.

I find replacing the NSX clutch to be an "easy" 8 hour job and I'm on my back with a floor jack. I replace the only the discs and bearings as long as the clutch is grabbing just fine.


I agree that goldNSX's potential diagnosis has plenty of merit.

I do suspect that a slipping supercharger can have a similar feel: a stab of the throttle could cause the SC to slip which would make the car feel like a something is holding it back due to the lack of air flow.
 
The dealer list price for the na2 flywheel, friction disc and pressure plate is around $4500. Throw out bearing, pilot bearing and maybe a fork and the bolts are extra. Add in Acura dealership hourly rates, shop materials and whatever taxes are applicable and I can see an 'over the telephone quote' of $6800 being in the realm of possible. If you phone up a dealership cold and ask for a quote on work when they have not laid eyes on the car, it would be stupid for the dealership to low ball the estimate. Its possible that you could knock the cost of the flywheel off which is $3400. But, if the vehicle has suffered a persistent slipping clutch the flywheel may have its own problems (has anybody resurfaced an na2 flywheel?

If the flywheel is damaged, an SOS 275 or 350 clutch would be a less expensive replacement option.

For mechanically experienced owners, a slipping clutch should be quite apparent. The OP has advised that they are not mechanically inclined and the fact that they are not able to identify whether the clutch is slipping suggests that the best advice is for them to take it to an experienced independent NSX shop or a dealership and have the problem diagnosed. Complete OEM na2 clutches are way too expensive to replace based just on forum advice.

Perhaps the best advice might be if other members can advise the OP on a competent independent shop close to them who could do the diagnosis. I am kind of 'out of the neighborhood' to do that.
 
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I suggested to take the car to a mechanic you trust to. The Acura dealership can but doesn't have to be necessarily your first option, at least it's the most expensive one. :D Regarding the quote or the potential costs of a new clutch I strongly suggest to take your car to a mechanic you trust to. The clutch of the NSX is not different from any other MT car, at least how a slipping clutch is diagnosed. Your mechanic might check other things too and draw his conclusion what to do best/first before 'feeding the expensive dealership'.
If you like to DIY that's a pretty good video: https://www.youtube.com/watch?v=Q_jwEoTZ__Y
A pretty good test can be seen at 2:00. Just don't do it too often.
Just a word of caution or 'liabilty waver': forums are a great thing in general but also some kind of a source of misunderstanding esp. while describing technical things.

Out of curiousity: do you rest your left foot on the clutch while driving? You should not.
 
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goldNSX said:
I suggested to take the car to a mechanic you trust to. The Acura dealership can but doesn't have to be necessarily your first option, at least it's the most expensive one. :D Regarding the quote or the potential costs of a new clutch I strongly suggest to take your car to a mechanic you trust to. The clutch of the NSX is not different from any other MT car, at least how a slipping clutch is diagnosed. Your mechanic might check other things too and draw his conclusion what to do best/first before 'feeding the expensive dealership'.
If you like to DIY that's a pretty good video: https://www.youtube.com/watch?v=Q_jwEoTZ__Y
A pretty good test can be seen at 2:00. Just don't do it too often.
Just a word of caution or 'liabilty waver': forums are a great thing in general but also some kind of a source of misunderstanding esp. while describing technical things.

Out of curiousity: do you rest your left foot on the clutch while driving? You should not.
Click to expand...

>Out of curiousity: do you rest your left foot on the clutch while driving? You should not.



No, I don't rest the foot on the clutch pedal.


I probably would not do this test. However, I just wonder how would a mechanic perform the test to find out if it is the clutch, would it be similar to the video above?

After calling Niello Acura Dealer for the 2nd time to ask why it is so expensive, Dave, the part service dept, explained that one would replace all of the components including Flywheel, which can not be resurfaced because it is dual disc, when replacing the clutch. And he suggested that I would want to put in the aftermarket parts such as Compt Tech or SOS parts for durability because of CTSC. OEM parts will not last very long. But at this time, we only suspect the clutch that is bad or/and might be some thing else.
 
He may have said dual disk; but, he meant dual mass flywheel. The na1 is dual disk. The na2 has a dual mass flywheel with single disk and like he said, I don't think Honda provides for resurfacing the dual mass flywheel.

If your flywheel is OK, the lowest cost solution is to replace the Honda friction disk. If the flywheel is damaged the lowest cost solution is an SOS 275 or SOS 350 clutch. If you need to replace the clutch, more 'performance' is not necessarily better. Performance clutches can be harder to drive and may make driving in stop and go traffic absolutely miserable. The clutch pedal is much stiffer and the engagement is much faster (more like an on-off switch). Check the diameter of the super charger pulley. If you have the low boost pulley then the SOS 275 may be just fine and has a feel that is close to the original Honda clutch. But, we are getting ahead of ourselves. First step is to confirm that it is the clutch that is the problem.
 
Old Guy said:
He may have said dual disk; but, he meant dual mass flywheel. The na1 is dual disk. The na2 has a dual mass flywheel with single disk and like he said, I don't think Honda provides for resurfacing the dual mass flywheel.

If your flywheel is OK, the lowest cost solution is to replace the Honda friction disk. If the flywheel is damaged the lowest cost solution is an SOS 275 or SOS 350 clutch. If you need to replace the clutch, more 'performance' is not necessarily better. Performance clutches can be harder to drive and may make driving in stop and go traffic absolutely miserable. The clutch pedal is much stiffer and the engagement is much faster (more like an on-off switch). Check the diameter of the super charger pulley. If you have the low boost pulley then the SOS 275 may be just fine and has a feel that is close to the original Honda clutch. But, we are getting ahead of ourselves. First step is to confirm that it is the clutch that is the problem.
Click to expand...

Hey, Old Guy! Thank you so very much for the info. I will need to find the time to take it to the shop, which is 2 hours drive from my place. Hopefully, it won't stall on the way there.
 

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