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Overheating, please help.

1

1clean98supra

Registered Member
Joined
30 January 2006
Messages
11
Maybe someone has had this problem. I have bled the sysem like the manual says about five times. I have searchd and read the DIY's and the FAQ's already.

I will bleed the system first then go for a short drive to test the car. When I am driving about 65 at a low RPM in 5th the car does not overheat, but when I run the RPM's up more than about 3500 the car will get warm. It also will get warm after I pull the car back in the garage after doing the test drive. If I stop at a stoplight the car temperature will start to go up, but then when I get back up to speed, the temp drops back to the middle.

When I try to bleed the system again after driving, I get nothing but hot air coming out of the rear firewall bleeder as well as a bit of air from the top radiator bleeder, would this be because I didn't bleed it right?

I had the thermostat replaced the day I got the car.

I thought the radiator might be bad, but if it is would it cause all of this air to be in the system?

One other thing, I read in a post when Scafia was diagnosing his problem and someone wrote a message that the top radiator hose is supposed to be hotter than the upper one. Evertime I get in from driving my car, the lower hose is hotter.

As much as I hope this isn't the problem, does this sound like a blow head gasket, please give me some advice.
 
So it is possible to have a blown head gasket without having milky oil? I raced dirt track Toyota's for a few years and hadn't experienced a blown head gasket without water getting in the oil. I have changed the oil twice in the past two weeks trying to get the car running right, worried about water getting in the oil, but so far haven't detected any water in the oil.

Would it be possible for air to get in the system any other way or have these symptoms with any other problem?
 
It does not sound like a blown head gasket? You say you changed the thermostat when you got the car? Is there a reason why you changed it? You maybe possibly be bleeding it wrong I suppose but I doubt it. Do you notice is smoking at all? or smell of coolant when it gets hot? You may have a faulty temp sensor..... Just trying to give you some ideas let us know.
 
If you have a leak, a cooling system pressure test would confirm the gasket leak and you should see some antifreeze in your oil.

The oil analysis for our 2003 Buick detected anti-freeze even though the temps were normal and radiator fluid was not getting low this concerned me since it has only 45K miles. A cooling system pressure confirmed a leak from intake gasket - and we just learned from the local dealer that this is not uncommon though not at this low mileage! Initial estimate $1400. GM agreed to pay for the parts (about $500) under goodwill since we had passed the 36K miles when brought to their attention; labor was $640.
 
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I had a 97 Boxster that I had paid 15.5K for, a guy traded me straight up for the boxster, I drove to N.C. in my car and picked his up. I began my drive back. Less than 30 minutes after leaving the guy and trading titles the car began to get a little warm, luckily I always keep an eye on gauges and noticed it. Knowing a tad bit about cars, I drove to the closest auto parts store and purchased a thermostat. I was 1500 miles from home at that point with only about $1,000 in my pocket to get back to Houston.

I took the car and thermostat and car to a little hole in the wall shop and had him replace the thermostat and he did a pressurized coolant fill. When I left the guys shop I decided to just take it easy that I only wanted to make it home. I assumed problem fixed because not once did the car start to overheat on the drive, but it was all highway driving. As soon as I would pull into a gas station etc., I would shut the car off.

I don't notice any smoking from the tailpipes at all.
 
A block test checks for exhaust gases in the cooling system. any good qualified shop can do this. By using a special tester the fumes in your cooling system are checked for combustion gases. i suggest this test to verify a head gasket leak.. if the tester sees combustion gases in the cooling system the blue fluid turns green. it is a very acurate test.
 
Listen to Eiffel..bleed the cooling system as the manual suggests.


If you still have the issue.

Head gaskets can fail in different ways..

1: Failure between coolant and oil passages (milky oil and missing coolant)

2: Failure between the coolant passages and the combustion chamber (Overheat under load and missing coolant) NOTE! you will NOT see white smoke from the exhaust if the failure is very small.

3: Failure between oil passage and the external seem of the head to block mating surface (Oil leaking externally at the head gasket)



Doing a "Block test" is very important..using the chemical you can see after running the motor when hot if combustion gasses are finding their way into the cooling system.

Be patient...sometimes it takes a long time to see the chemical change color.
 
Side note to all the good suggestions, is your radiator fan working when the car gets warm ? I had a blown fuse that caused the fan to fail in the past that have similar results - ok on highway drive, but will warm up as soon as I stop the car.
 
I took the radiator out just now, I am taking it by a radiator shop on Monday morning. Before taking it out I tried to bleed the system one more time as the manual shows and the car did the same thing whe driving it, It was doing fine and then I sped up a bit to 70 and the temperature went up to about 3/4 on the gauge. I then slowed back down to 60 and the temp dropped back down. When I pulled the car in the garage, the temperature gauge began to rise, so I killed the motor and then turned the key back to the on position to let the fan run for a minute to help cool the car. The radiator fan in the front was on full speed pulling air through the radiator. I cracked open the bleeder by the rear firewall to see if there was water there, but nothing came out, but steam for a good 5 minutes.

So if the radiator turns out to be fine when they test it, I will put it back in and try a block test.

While sitting in the car keeping me company, my girlfriend found a receipt under the driver's seat from Leith Acura in North Carolina, dated 12-22-06 for $576. It shows that they replaced a coolant hose and then pressure tested the car. Perhaps I will call them on Monday and find out exactly what the car was taken in to the shop for. Hopefully thy'll remember.

Anyhow thanks for the advice and I'll keep you updated. I am worried the problem may be choice number two from Zahntechs head gasket failure possibilities.
 
Just wondering how many miles you have on the car and if you asked the seller about the problem.

I read that a vaccum or compression test can detect if you have a head gasket leakage.

Good luck.
 
I was battling a overheating problem for a good year. The only time it would get hot though was at the track. The Acura Dealership I take it to finally did a compression check and sure enough my head gasket is starting to go. I suggest you get this checked out it's fast and cheap. The car goes in next week for the gasket and SOS stage 3 goodies. The labor is not cheap though since they have to drop the engine :eek:
 
I replaced the cap last weekend.

I called the owner when I had the overheating problem the day we traded cars, he claimed that he had not had a problem with it at al. He told me he had gotten a radiator hose relaced a few months beore and he had driven the car on a 300 mile roundtrip a week before I picked it up and is having no problems with it.

Sounds like I will be having a compression test done on the car on Monday. It has 135K miles.
 
he had gotten a radiator hose relaced a few months beore
Click to expand...

Consider this an admission of guilt! Burst hoses are difficult to detect while driving and a normal driver would only become aware when engine damage has resulted.

Your symptoms *sound* like a head gasket or a cracked head. A block check is in order....if it shows positive you are going to have pull both heads.

If you do have a cylinder gasket/head issue: you might as well pull the engine. While the job can be done with the engine in place, it is extremely difficult to do so. The time spent pulling the engine will be paid back 2-3:1 on assembly.

Good Luck

Drew
 
It would be cheaper/easier to test for combustion gasses in the coolant than to pull the plugs for a compression test. You can buy a kit and do this test yourself if you have a hand vacuum.
 
Compression test will likely tell you nothing...if the Gasket failure is not bad enough to give you white smoke..the compression test will not show it.


Do the block test, most auto parts stores have them...NAPA does for sure.

Make sure the system is bled properly and that the level in the bottle is at the MIN mark...then run the car till warm with the tester on the bottle neck.

After the motor is wam run the car at 2500-3000RPMs off and on for around 15 mins.

I suspect the blue fluid will turn yellow/green in that time.

Make sure that the coolant does not make it's way up to and inside the tester!..then you will have to clean it out and start over.

Good luck....JZ
 
Just put the radiator back in and did the compression test today, I got about the same from each cylinder, slightly above 180.

I checked for the block test at autozone and oreilly, neither had one. I will go to a NAPA when I get out of class tommorrow afternoon.

I will try the block test first and then if it turns out good, I guess I'll take the radiator to a shop then.
 
I decided to have a lok at the coolant tank. Upon taking it off of the car and running some water in it, I noticed that the top return nozzle was clogged up to the point that absolutely no water could pass through it, not the over flow one, but the one that connects to the intake. Anyhow I put a drill bit in it and spun it around until what appeared to be some dirt came out. I am sitting in the car right now after putting the tank back in to let it heat up. I'll let you know the result, could this be the problem? I was going to buy the block test kit and decided to try this first, the guy n the phone at Napa told me to check the entire cooling system before hand that it could be a vey simple problem. I'll let every one know in a short few minutes whethor it fixes it or not!
 

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