[ItsChristianInHD]

I was wondering if we/anyone figured out why the thermostats on the LGX go bad. I replaced mine earlier this year but then I came to the realization, my car is 7 years old and I always thought the coolant change was every 7years/150k miles or whatever. Turns out it’s 5 years.

Is it dexcool that causes this issue? If you don’t change it at the recommended time it causes the thermostats to go? Or is it just a cheap part/design flaw?

I wonder if anyone figured that out.

[Gen6cyl]

My 21 lgx has 73k miles with no thermostat problems. My manual says change at 150k miles. Says nothing about time. I might try the strips you dip in the coolant to check the condition.

[conall]

I don't know the answer to your questions.
But, mine went bad and was replaced at 6 years;
and I only had 41.5k on mine.

[ctrlz]

Originally Posted by ItsChristianInHD

I was wondering if we/anyone figured out why the thermostats on the LGX go bad.

It is rare that anyone looks at replaced parts to do any kind of failure analysis. I always do, but I don't work in a shop with pressure to get things in and out.
I do have a connection at a local chevy dealer, and I am dying to get my hands on a few oil pumps to give them a look over.

[ItsChristianInHD]

Originally Posted by conall

I don't know the answer to your questions.
But, mine went bad and was replaced at 6 years;
and I only had 41.5k on mine.

Around same time/mileage for me too. I was always curious and I know it’s a really out the blue question but I see it a lot in the Facebook groups of V6 thermostat issues and I’m just like “is there a design flaw or are we missing something?” lol.

[ItsChristianInHD]

Originally Posted by Gen6cyl

My 21 lgx has 73k miles with no thermostat problems. My manual says change at 150k miles. Says nothing about time. I might try the strips you dip in the coolant to check the condition.

Share your secrets!

But yep on mine it’s says every 5 years, lol.

Or every five years, whichever
comes first. See Cooling
System 270.

[Gen6cyl]

Originally Posted by ItsChristianInHD

Share your secrets!

But yep on mine it’s says every 5 years, lol.

Or every five years, whichever
comes first. See Cooling
System 270.

Maybe GM changed something about the thermostat in later years.Our GM manuals must be different, 270 on mine is about fuses. Can't find anything about time just 150 k miles. As far as secrets I think removing the engine cover and hood liner helps but probably not with thermostat. A hood vent like the lt1 would be nice.

[truckrglenn]

2017 service

[truckrglenn]

Originally Posted by ItsChristianInHD

Share your secrets!

But yep on mine it’s says every 5 years, lol.

Or every five years, whichever
comes first. See Cooling
System 270.

See my post above. Are you sure that you're looking at the 2017 Chevy Camaro Manual? I just looked and there's nothing about changing the coolant in that section other than the mixture and:
"See Maintenance Schedule - 336

Did you mistake this for coolant:

(6) Replace brake/clutch fluid every
five years. See Brake Fluid - 278.
and Recommended Fluids and
Lubricants - 346."

[S.Macias]

To the original question the thermostats were faulty to begin with where they wouldn't fully open. Unfortunately no one makes a performance 160 degree thermostat for the V6 (or none I can find) to replace with other than OEM.

Original coolant replacement was 150k miles or 7 years. Now its recommended at 5 years or 150k miles. It's the (4) on page 342 of the service manual that list 5 years.

Honestly it's really easy to do. I change mine every year. The LGX only needs 1.5 gallons, so one $30 concentrate bottle is enough when mixed with distilled water. Not a whole lot of videos on the LGX but it's fairly easy to do.

There is a small plastic valve on the radiator towards the bottom on the passenger side. It unscrews but not all the way. Have a large catch underneath. If you want to be lazy you don't need to remove the bottom but it gets messy. I actually drilled a small hole and run a filter from the radiator drain to under the car. Takes a minute to drill and place. Usually once it stops dripping I add some fluid to push out a bit more. Close the valve and add coolant. System is self burping so fill until full. Then turn the car on and let it warm up with the coolant cap off until it's warm and add as needed. That easy.

[Gen6cyl]

Originally Posted by S.Macias

To the original question the thermostats were faulty to begin with where they wouldn't fully open. Unfortunately no one makes a performance 160 degree thermostat for the V6 (or none I can find) to replace with other than OEM.

Original coolant replacement was 150k miles or 7 years. Now its recommended at 5 years or 150k miles. It's the (4) on page 342 of the service manual that list 5 years.

Honestly it's really easy to do. I change mine every year. The LGX only needs 1.5 gallons, so one $30 concentrate bottle is enough when mixed with distilled water. Not a whole lot of videos on the LGX but it's fairly easy to do.

There is a small plastic valve on the radiator towards the bottom on the passenger side. It unscrews but not all the way. Have a large catch underneath. If you want to be lazy you don't need to remove the bottom but it gets messy. I actually drilled a small hole and run a filter from the radiator drain to under the car. Takes a minute to drill and place. Usually once it stops dripping I add some fluid to push out a bit more. Close the valve and add coolant. System is self burping so fill until full. Then turn the car on and let it warm up with the coolant cap off until it's warm and add as needed. That easy.

Thanks, good information.I only remember hearing 16,17 year lgx having thermostat problems. Do you think thermostat should be replaced at 5 years or see it will make to second change. When should the second change be done ? Is a drain and fill good enough, flush not necessary,? I hope so. Did you fill at top tank? Thanks

[S.Macias]

I don't necessarily think the thermostat needs to be replaced every five years. I'd wait until you first notice it's stuck and then change. Mine was replaced around 75k miles and I'm at 157,500 this morning and no issues to report with it.

I don't think a full flush is needed unless when you notice significant debris from draining the coolant. Mine was changed at 45k, 75k (thermostat replaced), 100k, 145k and at 151k (hose sleeves installed). Haven't really seen any debris or signs of corrosion. Nonetheless I usually add coolant with the drain valve open to help push out more old coolant. Might not be a perfect flush but figure it's better than drain and fill

Top tank is filled, bottom goes up to the line about 1/3 the way. All done when completely cool.

One thing I would recommend replacing is the coolant cap. The cap expands to release pressure but after a few years mine didn't fully expand one day and collapsed the upper hose slightly. Thankfully I caught it right away but a good $10 buy for a piece of mind.

[Gen6cyl]

I think I'll do it the way you did, S.Macias, before 100k miles. Also I will keep a watch on the top radiator hose. Thanks

[ItsChristianInHD]

I got busy I didn't get a chance to circle back. Great information!

I'll keep an eye on my top hose as well.