I think my thermostat is stuck closed--HELP! - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Teddydog · 01-04-2018, 05:53 PM

Last night on the way home, I drove about 10 miles on the freeway and stopped for gas.

After getting gas and getting back onto the freeway, I quickly got a DIC message about overheating, then a more severe "idle engine" message and finally a "stop engine" message. Somewhere in there is suddenly dropped back to normal temperature and the DIC message went away. But then I was watching and could see the normal temp gauge climb up, drop down, climb again. So I was thinking it was a sensor problem, not actual overheating.

When it did it again and stayed like that (about 2 miles later), I pulled over.
It was a bad place to pull over, but I did and let it cool down for a while. I limped home with several stops to pull over, using back roads instead of the freeway for safety and ease of finding places to pull over. Initially, it seemed like the problem would go away for a short while (back to normal operation temp), but then climb back up to high and stay there until I shut off the engine and let it cool off a bit. By the time I got home, it was no longer returning to normal at all, so the stops got more frequent and longer.

This seems to me like the thermostat is sticking closed, causing the high temps as the water is stuck in the engine. When/if it decides to open, temp quickly goes back to normal when flow is restored.

Normally, a thermostat replacement is a simple job. When I called a shop for a quote for a flush/fill/replace, I was quoted 2 1/2 hours for labor for the thermostat! Holy Crapballs! Looking around a little, I guess it is way on the back of the engine, passenger side? REALLY? WTFH?

Can anyone supply further details on this job? Is it HARD? Or does it really take a while? I'm not really set up to drain and refill my cooling system in my driveway, thus was looking for a shop to do a flush/fill (it needs it anyway).

I have also seen a diagram that seems to show some sort of housing on the FRONT of the engine by the water pump. Would that be involved in a t-stat replacement?

HELP! Thanks.

Rob

Screwblower · 01-04-2018, 08:24 PM

Strange. Usually those hang open.
Had any issue before?

Sounds like a air pocket .

Pop the hood next time, feel of the top hose.
Collapsed or pressurized ?

acammer · 01-05-2018, 12:33 PM

Agree - sounds like air.

It's real easy to change the thermostat yourself - drain the coolant, pop the thermostat housing, and replace. Very minimal if any coolant loss that way - you can catch it all with a rag. Then fill it up till full, run the engine, let it push out the air, keep filling, once the temp comes up cap it off and you're set.

xc_SS/RS · 01-05-2018, 12:55 PM

to see if you've got a stuck thermostat: feel the hose that routes hot coolant to the radiator once the car is warmed up. if it's cold, and coolant temps are above 210-212, your thermostat hasn't opened and is probably stuck.

another thing is air bubbles in the cooling system as mentioned above. have you drained and refilled your coolant recently?

Teddydog · 01-09-2018, 12:39 PM

I didn't mention it specifically, but my car is an LT v6. I was shocked when quoted so much labor. My experience with other cars is that the thermostat is front and center on top of the engine. Not so for the LLT. Apparently it is in the BACK on the passenger side and is pretty well covered. Also the hose that goes to it is a rigid pipe, I think. I suspect all you guys with the "it's real easy" comments have V8s with a more traditional setup for the cooling system. : )

No, the coolant has not been changed or flushed since the car was new. It was already on my to-do list to get it flushed. I don't see how air can have gotten into the system.

Can anyone who has done this work on an LLT chime in about this job? Thanks!

Rob

acammer · 01-09-2018, 02:00 PM

Quote:

Originally Posted by Teddydog

I didn't mention it specifically, but my car is an LT v6. I was shocked when quoted so much labor. My experience with other cars is that the thermostat is front and center on top of the engine. Not so for the LLT. Apparently it is in the BACK on the passenger side and is pretty well covered. Also the hose that goes to it is a rigid pipe, I think. I suspect all you guys with the "it's real easy" comments have V8s with a more traditional setup for the cooling system. : )

No, the coolant has not been changed or flushed since the car was new. It was already on my to-do list to get it flushed. I don't see how air can have gotten into the system.

Can anyone who has done this work on an LLT chime in about this job? Thanks!

Rob

Apparently I failed reading comprehension. Multiple times.

Sounds like a real pain in the neck. Good luck!

Hellfighter · 01-11-2018, 02:46 PM

Isn't the coolant Dexcool, that needs to be changed every 3 years? 2009-2010 model, and is now 2018? Has not changed? seems like sludge would keep your stuff stuck or turn into sludge or something, someone chime in on this, sounds like hell.

polizzio · 01-13-2018, 09:35 AM

Quote:

Originally Posted by Hellfighter

Isn't the coolant Dexcool, that needs to be changed every 3 years? 2009-2010 model, and is now 2018? Has not changed? seems like sludge would keep your stuff stuck or turn into sludge or something, someone chime in on this, sounds like hell.

Oh yeah, that's a min of 8 years without a coolant flush. Best thing the OP can do is take it to a Chevy dealer or reputable shop and have them troubleshoot/repair.

8 years without a proper coolant flush brings in so many possibilities, and none are good. Mine is a 2012 V6 and my manual says "routine schedule" every 5 years or 150k miles. I just did mine like 2 months ago, flush and replace. And 5 years is a long time on coolant really.

If you neglect required service, you're gonna get a big surprise and big repair bills.

DON'T neglect required services, follow the Chevy schedules closely.

Teddydog · 01-17-2018, 12:55 PM

I THOUGHT I was following THIS part of the maintenance schedule:

First Engine Oil Change After
Every 240 000 km/150,000 Miles
. Engine cooling system drain,
flush, and refill, cooling system
and cap pressure check, and
cleaning of outside of radiator
and air conditioning condenser
(or every 5 years, whichever
occurs first). See Cooling
System on page 9‑17. An
Emission Control Service.

Note this appears to be the first mention in the Maintenance Schedule of the cooling system other than inspection. I did NOT see the parenthetical note about "or every 5 years, whichever occurs first." But why would I be looking there until I hit the section titled "Every 240 000 km/150,000 Miles". That's a messed up way to write in an earlier service need! 150,000 miles is TEN YEARS of average mileage. Why would they put a small note in the service area FIVE YEARS LATE????

So yeah, NOW I know the coolant is old. I was planning a flush/fill around now anyway.

I still have not done anything with this. Fortunately I have an extra vehicle to use.

Rob

01-04-2018, 05:53 PM	#1
Teddydog Drives: 21 LT1 RS M6 in SSM Join Date: Jul 2009 Location: Dupont, WA Posts: 454	I think my thermostat is stuck closed--HELP! Last night on the way home, I drove about 10 miles on the freeway and stopped for gas. After getting gas and getting back onto the freeway, I quickly got a DIC message about overheating, then a more severe "idle engine" message and finally a "stop engine" message. Somewhere in there is suddenly dropped back to normal temperature and the DIC message went away. But then I was watching and could see the normal temp gauge climb up, drop down, climb again. So I was thinking it was a sensor problem, not actual overheating. When it did it again and stayed like that (about 2 miles later), I pulled over. It was a bad place to pull over, but I did and let it cool down for a while. I limped home with several stops to pull over, using back roads instead of the freeway for safety and ease of finding places to pull over. Initially, it seemed like the problem would go away for a short while (back to normal operation temp), but then climb back up to high and stay there until I shut off the engine and let it cool off a bit. By the time I got home, it was no longer returning to normal at all, so the stops got more frequent and longer. This seems to me like the thermostat is sticking closed, causing the high temps as the water is stuck in the engine. When/if it decides to open, temp quickly goes back to normal when flow is restored. Normally, a thermostat replacement is a simple job. When I called a shop for a quote for a flush/fill/replace, I was quoted 2 1/2 hours for labor for the thermostat! Holy Crapballs! Looking around a little, I guess it is way on the back of the engine, passenger side? REALLY? WTFH? Can anyone supply further details on this job? Is it HARD? Or does it really take a while? I'm not really set up to drain and refill my cooling system in my driveway, thus was looking for a shop to do a flush/fill (it needs it anyway). I have also seen a diagram that seems to show some sort of housing on the FRONT of the engine by the water pump. Would that be involved in a t-stat replacement? HELP! Thanks. Rob

01-05-2018, 12:33 PM	#3
acammer GPI Sales Consultant Drives: 2011 Camaro 2SS SGM Join Date: Jul 2016 Location: Weedsport, NY Posts: 2,794 View My Garage	Agree - sounds like air. It's real easy to change the thermostat yourself - drain the coolant, pop the thermostat housing, and replace. Very minimal if any coolant loss that way - you can catch it all with a rag. Then fill it up till full, run the engine, let it push out the air, keep filling, once the temp comes up cap it off and you're set. __________________ GPI Max Package 2.0: Brodix BR7 heads/GPI porting, MAX3 cam, ST2116LSR, BSR Max Lift rockers, LS7 LSXR with 103mm TB, Vararam OTR, Mcleod RXT, G-Force/Strange 9" IRS setup with 4.63 gear. 551whp, 11.1@124mph. *Got a question about a GPI product? Feel free to shoot me a message!*

01-05-2018, 12:55 PM	#4
xc_SS/RS Drives: 2010 Camaro SS/RS Join Date: Mar 2014 Location: somewhere in MD Posts: 4,884	to see if you've got a stuck thermostat: feel the hose that routes hot coolant to the radiator once the car is warmed up. if it's cold, and coolant temps are above 210-212, your thermostat hasn't opened and is probably stuck. another thing is air bubbles in the cooling system as mentioned above. have you drained and refilled your coolant recently? __________________ 2010 2SS/RS Z/28 intake, NW, FAST 102, speed engineering LT's, some exhaust, ATI -10% pulley, GM flex fuel injectors, DSX flex fuel sensor, MGW shifter, HP Tuners, some suspension work, stickers and a little weight loss. 12.63 @113.53

01-11-2018, 02:46 PM	#7
Hellfighter Drives: 2013 Black ZL1 Join Date: Mar 2011 Location: Sugar Land/Texas Posts: 2,354 View My Garage	Isn't the coolant Dexcool, that needs to be changed every 3 years? 2009-2010 model, and is now 2018? Has not changed? seems like sludge would keep your stuff stuck or turn into sludge or something, someone chime in on this, sounds like hell. __________________

01-04-2018, 08:24 PM	#2
Screwblower Drives: 14' 2ss convertible Join Date: Oct 2017 Location: In my underwear Posts: 119	Strange. Usually those hang open. Had any issue before? Sounds like a air pocket . Pop the hood next time, feel of the top hose. Collapsed or pressurized ?

01-09-2018, 12:39 PM	#5
Teddydog Drives: 21 LT1 RS M6 in SSM Join Date: Jul 2009 Location: Dupont, WA Posts: 454	I didn't mention it specifically, but my car is an LT v6. I was shocked when quoted so much labor. My experience with other cars is that the thermostat is front and center on top of the engine. Not so for the LLT. Apparently it is in the BACK on the passenger side and is pretty well covered. Also the hose that goes to it is a rigid pipe, I think. I suspect all you guys with the "it's real easy" comments have V8s with a more traditional setup for the cooling system. : ) No, the coolant has not been changed or flushed since the car was new. It was already on my to-do list to get it flushed. I don't see how air can have gotten into the system. Can anyone who has done this work on an LLT chime in about this job? Thanks! Rob

01-17-2018, 12:55 PM	#9
Teddydog Drives: 21 LT1 RS M6 in SSM Join Date: Jul 2009 Location: Dupont, WA Posts: 454	I THOUGHT I was following THIS part of the maintenance schedule: First Engine Oil Change After Every 240 000 km/150,000 Miles . Engine cooling system drain, flush, and refill, cooling system and cap pressure check, and cleaning of outside of radiator and air conditioning condenser (or every 5 years, whichever occurs first). See Cooling System on page 9‑17. An Emission Control Service. Note this appears to be the first mention in the Maintenance Schedule of the cooling system other than inspection. I did NOT see the parenthetical note about "or every 5 years, whichever occurs first." But why would I be looking there until I hit the section titled "Every 240 000 km/150,000 Miles". That's a messed up way to write in an earlier service need! 150,000 miles is TEN YEARS of average mileage. Why would they put a small note in the service area FIVE YEARS LATE???? So yeah, NOW I know the coolant is old. I was planning a flush/fill around now anyway. I still have not done anything with this. Fortunately I have an extra vehicle to use. Rob