So what are your opinions on thermostats?

[cusideabelincoln]

I have this weird issue that my car, when it was running, ran a little bit hotter than it should even after replacing the thermostat with another OEM one.

I'm thinking of putting in a cooler thermostat, and I'd like to hear what your opinions and experiences are in the matter. Should I go with a 160 degree thermostat or will a 180 degree be better?

Whenever I save up some money, I do plan on putting a chip in the car. From what I've read, 160 degree stat works best with an aftermarket computer. Since thermostats are cheap, I could probably put in a 180 degree thermostat now and consider a 160 degree one later.

Opinions? Thanks.

[geoffinbc]

Low temp stats cause a lot of long term problems and return no benefit.

If your engine never gets hot enough to get water to its boiling point then the water in the crankcase will never evaporate. This causes the oil to become acidic and over the long term it will deteriorate your bearing material. You should not even run a 180* Stat it should be the stock one. Also complete combustion happens around 200*F giving you the most power. Oil is also at its optimum temperature meaning its flowing easy and not wasting power. Your gas mileage will even be better.

Hot is fine 200F to 215F is completely normal if running hard. Water in the rad is under pressure so it wont ever boil until it gets really hot and thats what you have to worry about. If steam pockets form heat wont be removed and you will get hot spots which can be damaging.

If you are relying on your stock gauge then ignore it. It is just a gauge to show a general idea. A scanner on the ECM will show a more accurate temp.

[IsaacHayes]

Whats the opinion on a drilled stat? I noticed a replacement 2.0l stat had a hole in it..

[cusideabelincoln]

I was a little skeptical to switch to a lower temp since the cylinder walls do have 90+ thousand miles of wear from running at OEM, so a lower temp might give me more blow-by. I don't really know if it would be noticeable or significant.

Also I don't have a temperature gauge in my car, just a temperature warning light which I've never seen come on. The only gauges I have are a speedometer and odometer and then a bunch of warning lights.

[ForcedFirebird]

Mine came with a 190*, and I went to a 180* with no problems. Just avoid going overboard, go too low and your car will never reach optimal operating temps.

[PCGUY112887]

What car do you have? I don't think I've ever seen a car that didn't have at least a temp gauge.

[cusideabelincoln]

It's a 92 Lumina.

There are a few early 90s GM cars which only had electronic gauges and warning lights.

[IsaacHayes]

Yeah don't ever go lower than 180. Any lower than that and the ECM will run in open loop and burn tons of fuel.

[SappySE107]

No it doesn't.

[IsaacHayes]

? I was always under the impression a 160 wouldn't allow the ecm to go into closed loop cause it thinks the engine is still too cold? That the temp was 170 or something....

[loner666]

itll come out of open loop but it will still use more fuel then say with a stock 195* thermostat..the general rule now is usually stay stock but if you have a 195* then going to 180* wont really effect it enough to notice

Ive been running a Hypertech 180* for almost 2 years now..no problems yet

[IsaacHayes]

Ah I see. What about drilling a hole in your stat? Good or no?

[torq455]

there's a reason the stat opens and closes. drill a hole and you might as well as take the stat out all together. though from the ones i've seen, there is an extremely tiny hole. assuming that's there for the cars in very cold climates where the stat isn't required to open much. that will force a very small amount of coolant though the radiator. otherwise, cold weather and short trips will turn the coolant in the block acidic quickly. using a 180 will not cause problems nor prevent the oil from getting hot enough to boil off any moisture in the crankcase, and won't cause and premature cylinder wear. had 180 in my sunbird 2.0 for 5 years and put at least 100K on it after i installed it! i saw it not too long ago. it had 230K on it then!! i used to run a 160 in my 94Z, but had to custom make that. that will cause the wrong kind of cylinder wear. won't allow the block to thermally expand correctly, and you will loose mileage. a cooler stat will gain you more power especially if you tune for it by adding. timing.

[SappySE107]

I drill a hole in mine to help get the air out. It certainly acts different than if you run no stat, so its not the same at all. No stat I saw 150 degrees. I see normal stat temp with the hole. Wasn't aware of acid but I haven't had a car together long enough to really worry about it.

[torq455]

my car went into closed loop today at 111*....sooo not an issue. Ben, i'm speaking more from a manufacturer's point of view of longevity and reliability.