02' WS6 Temp too high for my comfort

[Capt Pie]

Hello!

I've really tried everything I could before posting, and I'm at the point where I need a second set of eyes on this. I'm losing sleep in fear I have a serious issue.

Background:

This is my 3rd WS6. I remember on the last two, the temp gauge never went past the half-way mark. It always sat just to the left of it. On this one, It will go to the middle and a tiny nudge past it, then come back down when the fans kick on. In the morning on cold start, I can smell a very faint smell of coolant from the vents for about 10 seconds.

Car background:

- 2002 WS6 Trans Am M6.
- 28k miles
- I bought it a month ago from the original owner
- Always garage kept, babied, never raced, never seen rain. Garage queen (California)
- Car has basic mods - cat-back, intake, Pro-kit drop. Nothing serious.


Problem / Issue:

After a couple weeks of getting familiar with this car after not having one for years, I noticed the temp gauge would go a little higher than the previous ones I had. This, coupled with the faint smell of coolant, made me check the level, which was low. I filled it up, ran it for 500 miles, and the level stayed the same.

- Car gets warmer than what I'm used to in previous WS6's
- Very faint smell of coolant on cold start for about 10 seconds, then goes away.
- Very faint smell of coolant after driving it, coming from what seems like the radiator cap

What I've done and verified:

- Fans do kick on when the needle starts to move slightly past the half-way mark, and settles in the center. Only moves back down once moving.
- Heat and A/C work fine
- Flushed / replaced coolant, and "burped" the system several times. Old coolant had 1000 miles on it previously and looked fine (dex-cool)
- Replaced water pump
- Replaced t-stat
- Replaced water pump gaskets
- Replaced radiator cap
- Replaced the belt since I had it off anyway
- Did a pressure test (note - there was a very faint air leak coming from the testers cap. Could only get an accurate read when I held it down tight. Very finicky)
- Could not find any leaks
- No smoke coming from exhaust

Additional info / Things I'm not sure about:

- After the car gets to temp and runs as described, all of the hoses that connect to the water pump are very hot
- Before replacing the parts, the engine would steadily pour coolant from one of the small holes right under the radiator cap into the radiator. This no longer happens after replacing the parts. I don't know what this means.

This is where my knowledge on this ends. I don't know what to do / check at this point and I haven't slept in two days because of it. Any help, ideas, or suggestions on what to do next would be wonderful. If you have any questions or would like pictures of anything, please let me know.

Thank you so much. Looking forward to being part of this community!

[JustinEntropyRad]

What's the running temp at idle? Is the water pump factory original? I wonder if it's no longer airtight from sitting, even though such low mileage??

All speculation.

[SMWS6TA]

Well let's see...a lot to cover.


Your car yr (99-02) have what is called a static gauge for the temperature. Meaning it doesn't show an accurate reading like on the 98's. Only 2 ways to get an accurate reading are to install an aftermarket water temp gauge or IIRC you can hook it up to a data logger and it should record the temps the pcm is seeing.

The pressure test was it done while the engine was cold or after it was warmed up? It's possible to get 2 different readings because when the block is cold everything is contracted, warm it up and everything expands, If you have a slight head gasket leak it may be in the beginning stages.

Hoses will warm up, the small tube you are referring to connects to the cross over tube for the heads that is under the intake/throttle body. You should with the cap off see coolant coming back into the radiator after the t-stat warms and opens up. If you have the car up to temp and still no coolant flowing then you may have some air still in the system causing a air lock. A PITA to get rid of but you can do it.


Our cars are also bottom-feeders, meaning they cool off when the car is driven, the air damn that is under the car forces air up into the radiator. Your temps at idle will be slight more than when your out for a drive. But you should see the needle come down a little. Make sure you have one, I have seen cars with these removed or damage.

The startup exhaust smell/vapor is most likely condensation in the exhaust. Takes a few minutes for the CATS to warm up to burn off unburnt fuel, even more so if you have headers. Now I'd be worried if you said you saw white or light gray smoke every time you step on the peddle or when you see it as a cloud behind you on the road. That is a major hint that you have coolant head gasket leak.

If the radiator cap is OEM, I'd just go ahead and replace it. the seals do go bad over time.



So far all the stuff you've done is about right. Others will chime in.





Just remembered this - one more thing to check in case you seem to be losing coolant. Check the passenger side floor board. If it's damp or even wet, looks like the heater core is leaking into the car. Can't remember what member had that happen to him last yr. But I know he had a bitch of a time finding his leak till someone pointed it out to him.

[Capt Pie]

Well let's see...a lot to cover.


Your car yr (99-02) have what is called a static gauge for the temperature. Meaning it doesn't show an accurate reading like on the 98's. Only 2 ways to get an accurate reading are to install an aftermarket water temp gauge or IIRC you can hook it up to a data logger and it should record the temps the pcm is seeing.

The pressure test was it done while the engine was cold or after it was warmed up? It's possible to get 2 different readings because when the block is cold everything is contracted, warm it up and everything expands, If you have a slight head gasket leak it may be in the beginning stages.

Hoses will warm up, the small tube you are referring to connects to the cross over tube for the heads that is under the intake/throttle body. You should with the cap off see coolant coming back into the radiator after the t-stat warms and opens up. If you have the car up to temp and still no coolant flowing then you may have some air still in the system causing a air lock. A PITA to get rid of but you can do it.


Our cars are also bottom-feeders, meaning they cool off when the car is driven, the air damn that is under the car forces air up into the radiator. Your temps at idle will be slight more than when your out for a drive. But you should see the needle come down a little. Make sure you have one, I have seen cars with these removed or damage.

The startup exhaust smell/vapor is most likely condensation in the exhaust. Takes a few minutes for the CATS to warm up to burn off unburnt fuel, even more so if you have headers. Now I'd be worried if you said you saw white or light gray smoke every time you step on the peddle or when you see it as a cloud behind you on the road. That is a major hint that you have coolant head gasket leak.

If the radiator cap is OEM, I'd just go ahead and replace it. the seals do go bad over time.



So far all the stuff you've done is about right. Others will chime in.





Just remembered this - one more thing to check in case you seem to be losing coolant. Check the passenger side floor board. If it's damp or even wet, looks like the heater core is leaking into the car. Can't remember what member had that happen to him last yr. But I know he had a bitch of a time finding his leak till someone pointed it out to him.

Thank you for the detailed reply!

The air dam is there. Once I get moving, the temp will come back down and rest just to the left of the needle. My scare is that my other two never went past that mark. I'll get a reader and hook it up to record / monitor the temps

I have done the pressure test both at warm and cool, and both times the only leak was with the actual pressure tester. I've done it twice, but I believe I got the same one. I will try again from a different parts store to make sure I get one that isn't so finicky.

The radiator cap is brand new.

I haven't checked the passenger side floorboard, but I will after driving it. I never smell coolant inside the vehicle until the next day, and it comes from the vents for just about 10 seconds, very faint. When cleaning the car weekly, I've pulled the mats out and haven't seen anything, but I was never LOOKING for it.

Before I did all the part swaps, I ran it for 500 miles and didn't lose any coolant, so I'd like to think that is a good sign. With how well it was driven and maintained, I would have a hard time believing it is a head gasket. But with these cars, anything is possible.

There isn't any smoke at all coming from the exhaust. On cold mornings you get the vapor coming out, but it's the same as any other car. The last thing I have to do is drain the oil to see if coolant is mixed in just to be sure. It isn't overheating - but it is getting warmer than I'm used to with my past two cars, so that paired with the very faint smell, leads me to believe SOMETHING isn't how it should be.

[pajeff02]

Like Scott said, don't rely on the factory temp gauge. Ours reads right around 205, no matter what the actual engine temp is. On my scanner, the temp is generally in the 185 to 195 degree range with a 180 degree thermostat. Just a note - The cooling systems in these engines will airlock when you drain and refill the cooling system, so ensure that both your hoses get hot as your engine gets up to the thermostats rated opening temp.

[RONS98TA]

You can also just check the oil dip stick to see if it looks like chocolate milk. This will indicate a head gasket also. I dont think that is your issue. You def, at full operating temp , should have a nice steady flow of coolant coming from the hose you mentioned before. It's the small 1 that you can see when you pull the radiator cap off. I don't think this will cause it to run hot, but you must have an air bubble in there causing it to not flow the water. Inside the car, you need to pull out the floor mat and pull back the carpet on the passenger side, to see if the heater core is leaking. Check for moisture or a slightly slimy feeling under the dash and under the carpet. If it is a very small leak, it will be a PITA to detect it. Good luck.

[RONS98TA]

Also make sure both fans are working. Just don't go by the sound. Get a visual that both are working.

[Capt Pie]

Like Scott said, don't rely on the factory temp gauge. Ours reads right around 205, no matter what the actual engine temp is. On my scanner, the temp is generally in the 185 to 195 degree range with a 180 degree thermostat. Just a note - The cooling systems in these engines will airlock when you drain and refill the cooling system, so ensure that both your hoses get hot as your engine gets up to the thermostats rated opening temp.

I'll have to re-check the coolant coming from the little hole below the radiator cap. On the old T-stat, it would start pouring at cold start. I haven't checked it now because it's been too hot to take the cap off safely. All of the hoses are extremely hot. The two medium sized ones right next to each other on the passenger side, and the two big ones that go to the radiator. I am going to have to wait until Friday before I can go buy a scanner. I really appreciate your input

You can also just check the oil dip stick to see if it looks like chocolate milk. This will indicate a head gasket also. I dont think that is your issue. You def, at full operating temp , should have a nice steady flow of coolant coming from the hose you mentioned before. It's the small 1 that you can see when you pull the radiator cap off. I don't think this will cause it to run hot, but you must have an air bubble in there causing it to not flow the water. Inside the car, you need to pull out the floor mat and pull back the carpet on the passenger side, to see if the heater core is leaking. Check for moisture or a slightly slimy feeling under the dash and under the carpet. If it is a very small leak, it will be a PITA to detect it. Good luck.

Ok cool - I did try checking this way and it appeared to be normal to me. I've done hundreds of oil changes and have never seen a blown head gasket so it appears to be fine. It doesn't smell any different, either. Last night I went out and pulled the floor mat, and got in there, twisted myself upside down and pulled some muscles I forgot I had. Bone dry. I got in there with lights, and sniffed around and could not find a single drop of coolant. I will try again after it has been running to see if I get different results. Thank you so much for taking the time to help!

Also make sure both fans are working. Just don't go by the sound. Get a visual that both are working.

Both fans are working. I got under it and saw that they both came on. It is really difficult to see from the top down, so I just put it up on ramps. I was really hoping it would be something as simple as this.

[theorangeguy]

Are the radiator fins full of junk? Bugs, grass, dirt, rocks, etc?

[SMWS6TA]

Good point Pat. I somehow sucked up a plastic bag and it was enough to spike my temps.

[SMWS6TA]

I'll have to re-check the coolant coming from the little hole below the radiator cap. On the old T-stat, it would start pouring at cold start. I haven't checked it now because it's been too hot to take the cap off safely. All of the hoses are extremely hot. The two medium sized ones right next to each other on the passenger side, and the two big ones that go to the radiator. I am going to have to wait until Friday before I can go buy a scanner. I really appreciate your input

Sounds like the previous t-stat had a bypass hole drilled into it. Old school trick to keep sticking t-stats from cutting off coolant.

[theorangeguy]

Good point Pat. I somehow sucked up a plastic bag and it was enough to spike my temps.

i've had the same thing happen. Seems like you guys covered all the overly complicated stuff

[SMWS6TA]

It sometimes is really just the old ball stuff that causes the problems....When I saw the bag I was like where the hell that came from? When on the road I avoid trash because you never know what is in it.

[Capt Pie]

Are the radiator fins full of junk? Bugs, grass, dirt, rocks, etc?

I spent a lot of time under the car looking for leaks and the only thing I really saw was a black widow web on the corner of the air dam, a dead daddy long leg in a web, and a few little spider nests around the nose, but I didn't see anything in the radiator. For safe check, is that something I could take compressed air and blow it out? Or would I need to remove it and hose it out. The car has been driven 2500 miles a year on sunny days, and kept in a garage with a car cover the rest of the time so there really isn't much dirt anywhere. There isn't even a spot of rust on the underside. Previous owner used filtered water to hand wash the car when needed if that gives you any indication as to how it was cared for.

Sounds like the previous t-stat had a bypass hole drilled into it. Old school trick to keep sticking t-stats from cutting off coolant.

I wonder if he was aware of the cooling issue before it was sold and tried to do this as a fix. The water pump was a stock GM water pump, so that wasn't changed before.

It sometimes is really just the old ball stuff that causes the problems....When I saw the bag I was like where the hell that came from? When on the road I avoid trash because you never know what is in it.

I'm really hoping it is something simple / easily missed like this. Seeing how it's winter and the car appears to be heating more than normal, I don't want to see what it's like in the summer. Also makes me wonder if he was aware of this issue and chose to sold it in the winter where it would be cooler outside. I think he is a pretty stand up guy and we still talk.

Bah..

Thanks again! You guys are really helpful and awesome.

[Too Fast]

Kevin.....you need to get some type of data from the PCM to see what the temps really are. Anything over 230* could be a problem, normal running temps of 195-220 are not an issue, no matter what the guage says. Until you find out the real temp, don't worry. There are small variations on mass produced vehicles, you may be experiencing that.

Based on everything you've posted.

[Capt Pie]

Kevin.....you need to get some type of data from the PCM to see what the temps really are. Anything over 230* could be a problem, normal running temps of 195-220 are not an issue, no matter what the guage says. Until you find out the real temp, don't worry. There are small variations on mass produced vehicles, you may be experiencing that.

Based on everything you've posted.

Sounds like the most logical step that I'll do tomorrow. Get real data to make sure there actually is an issue before chasing any other white rabbits (I think that is the saying? something like that)

I will report back tomorrow evening!

[Capt Pie]

Kevin.....you need to get some type of data from the PCM to see what the temps really are. Anything over 230* could be a problem, normal running temps of 195-220 are not an issue, no matter what the guage says. Until you find out the real temp, don't worry. There are small variations on mass produced vehicles, you may be experiencing that.

Based on everything you've posted.

Got a reader / recorder. I ran several tests but just found out it only saves the most recent test

At night in 45 degree weather, here are the results I pulled:

I drove it around the block, got it up to 45mph or so, then came back to the driveway and sat.

Got it up to temp where it was at 217. In the cold air, it would like to chill between 217 and 220. I turned it off, and continued to monitor. It went up to 232 degrees with the engine off. I started the vehicle, fans went on full speed, and brought it down to 215. From there when the fans turned off, it bounced between 217 and 221.

It was difficult to get the gauge where it normally sits since it was at night, cold air, and no traffic. I've had times where after the car sat after bumper to bumper, I'd start the car to see the temp gauge shoot to 3/4 of the way, then come back down when the fans kicked on and fluid started circulating.

I'm going to do some more driving tomorrow during the day to see if I get different results. Honestly it seems like the most simple fix for this is to have my fans programmed to come on earlier, as as soon as they do, it goes back down to my "happy Kevin temp"


Also, how do I upload pictures on here? I took a few i'd like to share.

[pajeff02]

Any idea what your thermostat is rated at? Could just be a cranky stat that isn't opening at its rated temp, or is sticking. Stock stat is around 195 to 198 degrees.

[Capt Pie]

Any idea what your thermostat is rated at? Could just be a cranky stat that isn't opening at its rated temp, or is sticking. Stock stat is around 195 to 198 degrees.

Just replaced it with a 186 t-stat, still acting the same.


Also last night I took the cap off when it was cold. Coolant right where I left it.

This morning, I noticed it was down about 3/4 of an inch. Forgive my lack of knowledge, but does this stuff evaporate or could this be the system just continuing to burp air out itself?

[35th-ANV-SS]

Replacing a stock temp t-stat with a lower temp t-stat will not do much in helping keep the motor temp cooler because the t-stat works in conjunction with the radiator fans. You'll need to reprogram the PCM to now have your fans turn on sooner to get the best results.