Ok first my car is basically a stock auto Trans Am with 140k miles on it. I tuned it to get the fans to come on at like 160 and it has a powerstat thermostat that is I would say 6 months and 10k miles on it. So with all that said here is the situation.

Friday night I take it to the local track, run it down once and go back to the staging lanes, as I am about to go into the box, I look at the gauges one last time and notice the temp gauge is about as far right as you can go. So I pull off the track and cut the car off immediately the fans continue to go so I just let it sit. Finally the temp goes back to normal running temp so I cross my fingers and turn it over hoping nothing is warped. Luckily it fires right up, I drive to the staging lanes maybe 1/2 mile away and park as I am parking the temp is starting to rise. So I turn it off and go sit for a few hours, I had a friend pick me up a thermostat b/c it seemed like the issue, so I go back to the car and drive home expecting a very rough trip stopping ever 2 miles. To my amazement it never got above normal temp. Well I am going to college and on Sunday I drove the 240 miles back to school keeping a close eye on it the whole time. Its an 80 degree day and cruising around 75-80 and it never gets above the normal running temp, so I to my apartment stop to get my mail, and drive to my spot look down as I'm about to turn it off and well the worst is happening it is way in the red so I turn it off. I haven't started it back yet and haven't had a chance to really do anything to it. I cant figure it out. I have never heard of a thermostat sticking sometimes(Im sure it is possible but dont know), it isn't leaking or spraying any coolant, and the fans are working like they are suppose to.

Im just curious if any others have had issues like this, or if anyone has any insight on what I should do. Thanks for looking

 

Well it looks like you have eliminated the fans, thermostat and external leaks.

Is the radiator topped off? (didnt mention it)

Your water pump might be smoked causing the coolant to not flow through the motor.
Another possibility could be a clog in the cooling system.

 

So did you do the thermostat?

 

Looks like he did.

 

Next time it gets hot according to the guage, pop the hood and see if the engine is really getting hot. You should be able to keep your hand on the intake at normal operating temps. If its too hot because your temp guage went into the red, there is no possible way you can keep your hand on it, or even the strut tower or air lid will be too hot also.

I say this because you could just have a failing temp sensor in your drivers side head. Seen it many times. You say nothing spraying out or leaking, well at red line or FARTHER to the right on the guage you should be loosing coolant into your overflow.

If your car is a 99+ then your engine will run perfectly with a failing temp sensor. Unlike my 1998, which will not run with a failing or failed temp sensor....or at least it runs like its going to fall apart.

And yes...t-stats can stick and **** with you for a week or two. So that very well could be the issue, even if its brand new. But first see if you're really getting hot or not.

.

 

When I changed the Tstat last time I changed the sensor also, it does seem to be getting hot but I admit I did not touch the intake but after poping the hood it was very hot. I didnt change the tstat yet b/c it seemed like it was a one time thing. I may get the radiator flushed after I change the tstat, as I think it would be crazy to flush it and then change the Tstat.

 

Yeah I felt like you didn't change it go ahead and do it.

 

Sorry to hear your car over heated again. Sounds like you got a plan in fixing the problem a flush may help you. Before I did a radiator flush on my car would run like 212 all the time I did the flush and it runs 193ish all the time now. Do that change your t-stat and if that doesn't work then you might try cleaning off that small intercooler looking thing that's behind the radiator. I forgot what its called I've seen on here where guys have done that and its fixed their overheating. Since its only over heating while the car isn't moving it seems like air flow is inadequate but at crusing speed you aren't gonna notice it.

 

Yea Im gonna do the change this weekend, but man is it going to suck doing it in my apartment complex parking lot. Who does the radiator flushing?

 

The best way to flush the radiator is with the t-stat out. Here's my write-up to flush and get every single drop of old coolant out.


Best/easiest way to flush and get every drop of old coolant out.

-Cold engine.
-Remove radiator fill cap.
-Remove the t-stat from the housing. Leave the housing attached to the rubber radiator hose, just remove the 2 housing bolts and pull it away from the water to pump to get to the t-stat. (2-3 minute job).
-Put t-stat housing back on. (1 minute) Just put one bolt in, no need to put them both in, there’s no pressure in the system during the flush.
-Take the entire radiator drain valve (petcock) "off" and let it drain, don't just open the valve itself. It'll drain faster with it off and that’s what you want. ((Buy a new petcock valve before starting this flush process, sometimes they break when you remove them all the way just because they're cheap plastic and they get briddle over time, they're like $2.00))
-Take a hose and stick it in the radiator fill cap, running medium to high.
-Start the engine.
-Let it run for about 15-20 minutes or until the water is running out the drain CLEAR.
-((If you want to, you can wait till it runs clear, close the drain valve, add a bottle of radiator flush and let it run for 15 minutes, then drain it all again. Then open the drain and put the hose in for about 5 minutes run it all out till its CLEAR. The flush chemical will help break up the crap thats stuck DEEP in there.))
-When it runs clear your entire system is clean.
-Remove the overflow reservoir from the car and clean it out real good. (I had to use gasoline to clean mine out because the sludge and grime was so thick inside. The gas broke it all down and then it flushed right out. I filled it about 1/3 up with gasoline and shook the hell out of it real vigorously, the black stuff kept coming out. I did that like 4 seperate times till no more chunks of black crap came out. Make sure the lines that go to the reservoir are also cleaned out. My sludge came from my power steering fluid leaking into my coolant system.)
-Put the t-stat back in.
-Put the overflow reservoir back in.
-Put the drain valve back in. Use the new one, what the hell.
-Put half a jug of Dexcool in the radiator. (Or if you live in very cold places, 1 to 1 ½ jugs of Dexcool)
-Fill the rest with water.
you do not need to use distilled water, clean hose water is just fine, just make sure your city water is clean and not total crap quality.

**Bleeding the system of air:
Start it up and let it run and warm up till the t-stat opens. I rapidly squeeze the upper radiator hose like 20 times while its warming up to help move any air bubbles through the system and by the t-stat on the engine side. You’ll see the level drop as you squeeze it, its sucking the coolant through the system. You wioll soon see the coolant start to flow in the radiator fill neck, once it starts to flow the level should drop down alot, immediately top it off with coolant/water. Then the flow will stop. Wait one more time for the t-stat to open again and start to flow, if it drops down again top it off again. Do it a 3rd time if you want to make sure. I always massage the upper hose during the whole process to keep any air bubbles moving through. Always works like a charm. Just keep checking your temp gauge until the t-stat opens for the first time to make sure it’s not sitting there overheating from a trapped bubble. May take 10-15 minutes for the t-stat to open the first time.
If you do start to get hot while sitting there and the t-stat will not open…..you have an air bubble on the engine side of the t-stat. Shut the engine off and rapidly squeeze the upper and lower radiator hoses again. Then start the engine again and see if the t-stat will open. Sometimes you just have to work those hoses to move the air through. Even after it seems topped off after a couple cycles…check it the next time you have a cold engine…top off if needed.

 

Wow that is a great writeup, Ill let yall know how it turns out

 

Had a busy day today. I woke up and changed the thermostat, turns out that was not the promblem. So after that I took it to get it flushed and on the way it got to 260 so I pulled over popped the hood and it wasn't really hot at all. I had my hand on the intake and radiator cap and they were both not very hot. So I got it flushed and also picked up a new temp sensor and after the flush I changed the sensor. I only got to drive 5 or so miles but it was running at operating temp. So maybe it is good

 

I hope you got the problem sorted out. I guess you will find out in a couple days.

 

I also hope you got it worked out...Hopefully it doesn't happen EVER again

 

Great. Yeah, those damn temp sensors like to scare the everluvin crap out of us......


.

 

Does the temp sensor pop up a code?I think i got the same problem.After 5 minutes of running you cant even touch the lines.Plus the engine block is extremly hot.I need help