I have never replaced one, and I have put 55k on this car, so not sure when it was replaced before (if at all).
When to replace thermostat?
- Thread starter Dohc98vteC
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Wouldn't be a bad idea to replace it as a preventive. Thermostats are cheap. Get a quality brand. Usually I have it replaced if the shop is flushing the cooling system. No need to rush into it, just have it done next time you take the vehicle in to the shop for some other service. If you haven't changed out the coolant, get it done also (in fact that would be a good reason to take it in). Make sure they flush the whole system (block and radiator) if it hasn't been done before or in a long time. Your manual should tell a frequency for cooling system maintenance.
On my own cars, I leave them alone until they act up or if it has ever been overheated from any cause. Currently 230,000 miles on the original t-stat in one of my cars.
I change the thermostat about every two years on three cars. In my experience the number one cause of stopping while running down the road, excluding flat tires, is the cooling system. It can also be the most expensive kind of breakdown.
I just replaced the one on my '94 Grand Am with ~ 177k miles as "preventive".
As I said above, if his coolant is in need of change, he should take it in asap and have thermo changed with the flush, but if his coolant has been maintained, he can wait to next convenient opportunity to do thermo.
So I take it thermostat failure can usually be traced back to neglecting proper a good coolant flush interval? Also, if a thermostat fails does it usually fail to open or does it fail to close? That's quite a scary thought if it fails to open and you're not paying attention to the coolant temp gauge!
I would change it every 100K miles as PM. It is my understanding that they don't fail often...
You can buy thermostats from AutoZone that fail open. I'm sure others have it as well.
Good call, BenJamm. I replaced one on my 92 Elantra just because it had been in there for a couple hundred thousand, and the new one, an all stainless/copper Stant failed to the barely open position inside of 5K. I put the old one back in it, and never had another issue with it. The old one was like new to begin with, shoulda left it be.
I'm going to make it a habit to replace mine every 7 years when I flush out the Amsoil coolant.
Yeah I have 130K on my thermo. I flush the radiator every summer though.
My only advice would be to toss the thermo in boiling water with a thermometer to see if it opens at the listed temp. before you go to install it.
My only advice would be to toss the thermo in boiling water with a thermometer to see if it opens at the listed temp. before you go to install it.
whever I replace a water pump and then the coolant hoses get replaced.
Similar here at 192K miles. My T-stat typically takes a home mechanic 4 - 6 hours to change. A total PITA. Even the dealer prices it out at 2.75 hours. So it stays there until it acts up.
I change my tstat when I change the radiator/heater hoses.....about every 30K-40K. People still change their hoses right? It's amazing that most people don't do the most basic of maintenance to their cars/trucks these days.
But when it does fail, you'd better hope it sticks open and not closed.
iT FAILED ON MY 97 iNTEGRA at around 90k. When that happened the car warm up slowly and the temp dives when I turn the heat on. Make sure you get one that failed on the open side. The t-stat on my wife's corolla has 100k miles on it and is still working.
I changed my t-stat only once in 35 yrs of driving, as pm.Only 2 brakedowns in my life. The first one 30 yrs ago was due to a pin size hole in the upper radiator hose. The second was a false brakedown due to driving up a steep hill in open loop mode, which cause red engine light to come on.
The best PM is change the coolant every 30k with distilled water. Also keep duct tape and spare coolant in the truck after 100k miles. By the way rubber coolant hoses are far superior than they were 20 yrs ago. I replaced my radiator hoses just recently with 11yrs and 100k miles on them, I saw no visible wear on them. That means no soft spots or swelling on either ends, with no chaffing on the inside as well.
The best PM is change the coolant every 30k with distilled water. Also keep duct tape and spare coolant in the truck after 100k miles. By the way rubber coolant hoses are far superior than they were 20 yrs ago. I replaced my radiator hoses just recently with 11yrs and 100k miles on them, I saw no visible wear on them. That means no soft spots or swelling on either ends, with no chaffing on the inside as well.
that can also be a bad thing. This 3.0L v6 vulcan engine in my 91 ranger hates T-stats. even good stant t-stats would only last 1 month at the most.
The system is clean and has been flushed and am using good coolant.
I even went so far as to getting bent over at the FURD dealershop and spent $18 !!! on an OEM unit. That lasted 2 months then started acting up.
I purchased one of those failsafe units from AZ in a lower temp since summer had arrived. No more than 1 day after having it installed, it locked in the open position. Boy was I ---- off!!. So I took it out, cut the ---- tabs off that allow it to lock open, and it's been fine since. Opens at about 190 like it's supposed to.
Do you also change the heater hoses and bypass hoses, oil cooler hoses, etc that carry coolant?
Every 40,000 miles seem like a very short interval to change hoses.
Hoses have improved drastically since the 1970's when I used to change hoses every 2 or 3 years. I've seen cars with 200,000 miles and 15 years old with the original hoses! I wouldn't take it that far...
Every 40,000 miles seem like a very short interval to change hoses.
Hoses have improved drastically since the 1970's when I used to change hoses every 2 or 3 years. I've seen cars with 200,000 miles and 15 years old with the original hoses! I wouldn't take it that far...
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