# 1st time overheating going up mountain



## snowwy66 (Nov 5, 2017)

You'd be losing coolant with a head gasket. 

One thing to try is to sit with the brake pedal applied and car in gear. Rev the motor and see if it heats up.

You obviously want to start at operating temp and not from cold. 

Don't know it's a good idea with today's cars but it's how we determined head or gasket back in the day with the 1 ton fire trucks. I worked for the county as a wrench. Once determined. Back in park and let idle. Didn't take long to cool back down.

And howdee neighbor. I just recently moved to the next county down.


----------



## 93bandit (Mar 2, 2020)

snowwy66 said:


> You'd be losing coolant with a head gasket.
> 
> One thing to try is to sit with the brake pedal applied and car in gear. Rev the motor and see if it heats up.
> 
> ...


I am by no means an expert, but holding the foot brake while reving the engine is a good way to overheat the transmission in a hurry, especially the torque converter. I don't think I would recommend doing this.


----------



## FMFRM250 (Jan 18, 2019)

snowwy66 said:


> You'd be losing coolant with a head gasket.
> 
> One thing to try is to sit with the brake pedal applied and car in gear. Rev the motor and see if it heats up.
> 
> ...





snowwy66 said:


> You'd be losing coolant with a head gasket.
> 
> One thing to try is to sit with the brake pedal applied and car in gear. Rev the motor and see if it heats up.
> 
> ...


Yes Howdy neighbor! Thanks


----------



## FMFRM250 (Jan 18, 2019)

Also I noticed coolant 1/2 inch low in overflow bottle. But after topping off and two more trips up canyon no movement.


----------



## Barry Allen (Apr 18, 2018)

FMFRM250 said:


> the temperature guage goes to the red I turn the A/C off and it immediately goes back to normal vertical position it has always stayed when going up mountains for years


That is a very weird thing that seems like a glitch more than a serious overheating problem.


----------



## snowwy66 (Nov 5, 2017)

93bandit said:


> I am by no means an expert, but holding the foot brake while reving the engine is a good way to overheat the transmission in a hurry, especially the torque converter. I don't think I would recommend doing this.


You're right. You're no expert.

And we never burned one out.


----------



## 93bandit (Mar 2, 2020)

snowwy66 said:


> You're right. You're no expert.
> 
> And we never burned one out.


Well alrighty then... I didn't realize I you were an expert, I'll be sure to keep that in mind next time. 

A 1 ton fire truck has different transmissions than a 16 Chevy Cruze.


----------



## snowwy66 (Nov 5, 2017)

93bandit said:


> Well alrighty then... I didn't realize I you were an expert, I'll be sure to keep that in mind next time.
> 
> A 1 ton fire truck has different transmissions than a 16 Chevy Cruze.


Really?


----------



## ChevyGuy (Dec 13, 2014)

Keep in mind the temp guages in these cars are fake. It's a computer readout. As long as the computer thinks the car is in it's normal operating range, the gauge will be parked at exactly one tick below half way. If it goes above that, it's a measure of how much the computer wants you to panic.

You'll need some other way of measuring temps to get a true picture. 

How old is the coolant? I'm wondering if it's gone bad and clogging the radiator. That's the only thing I can think of that would be affected by the sitting.


----------



## FMFRM250 (Jan 18, 2019)

Coolant was flushed when I preventively replaced the thermostat 2years 60k ago. I was able to verify 155 degrees with a borrowed scan tool . Thinking of throwing the old “known good” thermostat “. Back in it?


----------



## ChevyGuy (Dec 13, 2014)

It wouldn't hurt to pull the existing thermostat and put it in a pan of water and make sure it opens up all the way. Use the old one for comparison.


----------



## FMFRM250 (Jan 18, 2019)

Thanks!!!


----------



## Barry Allen (Apr 18, 2018)

ChevyGuy said:


> It wouldn't hurt to pull the existing thermostat and put it in a pan of water and make sure it opens up all the way. Use the old one for comparison.


What does a thermostat cost? For the trouble of testing it, a few bucks can buy a replacement that is a "shotgunning" solution?


----------



## Barry Allen (Apr 18, 2018)

ChevyGuy said:


> Keep in mind the temp guages in these cars are fake. It's a computer readout. As long as the computer thinks the car is in it's normal operating range, the gauge will be parked at exactly one tick below half way. If it goes above that, it's a measure of how much the computer wants you to panic.


That's the reason I say this is a computer glitch. To have a temperature gage that redlines or exceeds and then snaps back to normal when you turn off the AC has got to be the computer doing weird stuff.

Some coder typed a 1 instead of a 0 (or vice versa).


----------



## ChevyGuy (Dec 13, 2014)

Barry Allen said:


> That's the reason I say this is a computer glitch. To have a temperature gage that redlines or exceeds and then snaps back to normal when you turn off the AC has got to be the computer doing weird stuff.


I don't remember seeing posts here before with that observation. I think it's unusual. Regardless of the computer's response, I'd say this is an issue to take seriously as it could result in engine damage. 

Turning off the A/C will allow cooler air to get to the radiator. If that radiator is plugged up, that might be why it's experiencing problems on a hill.


----------



## FMFRM250 (Jan 18, 2019)

Are you saying because the condenser is in front of the radiator and while it is running it prevents cooler air from reaching the radiator. Once turned off the air hits the radiator at its normal temp not after passing by the condenser while operating? A thermostat is going to be $50. The weird thing about the temp rising was I had a scan tool attached and saw it climb up then drop rapidly. Back in the early 2000's I had a 2001 cavalier that ate thermostats like candy. The car would run fine around town in Kingman AZ at the time but drive up the hill from BullHead City to Kingman and up would go. Mechanic feels it is head gasket failing on the exhaust side ? Thank You everyone!!


----------



## snowwy66 (Nov 5, 2017)

The condenser is another radiator with heat.
So when the ac is running. 2 radiators are shedding heat. The coolant radiator won't be able to cool down as much. 

My semi runs about 10 degrees hotter with the ac on.


----------



## Barry Allen (Apr 18, 2018)

ChevyGuy said:


> I don't remember seeing posts here before with that observation. I think it's unusual.


This is what the original post states: "while traveling 1-80 almost near Park City the temperature guage goes to the red I turn the A/C off and it immediately goes back to normal vertical position"

My comprehension of that is a hot-running car and then, turning off the AC, it drops back to normal.

I guess I don't know that it is finger-snap quick, but it does seem to be a quick resolution to the problem.


----------



## ChevyGuy (Dec 13, 2014)

FMFRM250 said:


> Are you saying because the condenser is in front of the radiator and while it is running it prevents cooler air from reaching the radiator.


Correct. With the A/C off, the radiator will get cooler air. If the cooling system is marginal for some reason. that could make a difference. 

Question, when driving up the hill, what was your "air speed"? If you had a tailwind that was about the speed you were traveling, your airspeed would be near zero. That's not going to push much air though the radiator. And I'm not sure as the car will turn on the fan at highway speeds.


----------



## FMFRM250 (Jan 18, 2019)

UPDATE !!! I have over 133k as I travel for work Salt Lake City, Utah to Seattle, almost Canada, Denver, reno etc.. Was looking at my engine compartment and it was al coated in dirty black salty grit and I was thinking could my condenser & radiator be plugged up with this stuff as well? Took it to the local self wash place, and popped the little cover under the hood and saw the small place between the condenser and radiator full of bugs. So I carefully power washed it all out. Not sure if I got it all, but immediately after leaving I told my wife does the A/c seem cooler and she agreed. So then we drove up to Park City, Utah at 103 degrees outside with the A/C on and it only moved one line past normal. I can not believe it was just full of crap and had no air flow. I just wanted to make sure I followed up with the fix.


----------

