2G Thermostats Reviewed

[Rock2610d]

So, I have been running a little hotter than I like and decided to check my thermostat. I have a new oem style radiator, new water pump, no front mount intercooler, new cap on water housing. Car runs at 203 to 206 while highway driving and up to 213 in town. Not bad but I would like to keep it a little lower. SO:

I tested multiple thermostats. AC Delco 180 degree, Multiple Stants 170 and 180 degree, and two OEM Mit thermostats and one NAPA unit that had Stant on the box. NONE of these opened at their advertized temps. All of them had approximately a 1 inch spring limiting their wide open setting to about 1/2 inch. Most of the 180 degree units cracked at about 185 or so. The 170 degree Stant I tested cracked at 174 ish.

The only one with a bleed hole and poppet was the OEM units. None of the above worked to get my car running cooler. Even the 170 degree unit eventually ran at 203 to 206 on the highway.

Now, the fix. GATES Thermostat part number 33987 Its spring is 1.5 inches long and cracked spot on 180 degrees. Full open has a tad over 3/4 inch opening, which is alot when it comes to flow. My car now runs at 196 degrees on the highway and tops out at 203 in town. Fans do not even kick on unless I turn on my AC, and then goes to 196 degrees pretty quickly.

Photo attached of a oem unit and the gates unit.

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[estoyaqui30]

I just ordered one. ID like to bring down my temps a little too.

 

[Zex4g63]

I've been running the gates. Car runs cooler than it did with the oem.

Hits the like button

 

[2gmitsueclipse]

Were all of the units tested new at the time of the test? Were they tested in a pot of boiling water?

 

[Rock2610d]

Another couple things I forgot to mention. The opening size of a stock thermostat is 1.3 inches, the opening size of the stants is 1.6 inches and the opening size of the Gates is 1.5 inches. The Gates also has a bleeder hole and poppet just like the OEM unit instead of a V notch like the stants.

All were new except one of the OEM units. It was the one that was in the car when I bought it new in 1996. It actually cracked at a very high 190 degrees plus or minus a couple degrees.

Yes they were all tested in a pot of boiling water with a thermometer.

I was able to detect the crack temp by using tongs and lifting the thermostat top out and if it cracked the water that pooled on top of the stat would drain. If it was not cracked the water on top of the stat would just sit there.

 

[2gmitsueclipse]

Good work. I myself am a fan of gates products. Maybe a couple more could be added to the list. For example the Mishitomo stats both "stock" and "race".

 

[Rock2610d]

Could not find a stock temp mishimoto and did not want to pay the price for a race version that I would not use.

 

[boost97gst]

This is interesting. I swapped to a stant 170 and had noticeable drops in temps but the biggest by far was taping the condenser to the radiator. That helped drop things nearly 10 degrees

 

[Rock2610d]

Well now I am really confused. My second brand new OEM thermostat came in today. And guess what.....this OEM from Mit thermostat, in a MIT box looks EXACTLY like the GATES unit. Not the one that originally came out of the car from factory as pictured. So, I guess Mit is using Gates thermostats now? Moral of the story is that BOTH the thermostats in the posted photos are OEM Mit thermostats!

 

[enriquez2000]

I know its an old thread but did the gates part number change? If i search rockauto for our cars i get a diiferent number

 

[chrysler kid]

The OP doesn't specifically state to use only a gates thermostat, but that he used a gates thermostat part number which makes me think he found this thermostat under another vehicle which would work in our cars

 

[enriquez2000]

The OP doesn't specifically state to use only a gates thermostat, but that he used a gates thermostat part number which makes me think he found this thermostat under another vehicle which would work in our cars

Would this be the same for a 1g 6bolt? I noticed the rubber ring which 1g does not have.

 

[2gmitsueclipse]

Would this be the same for a 1g 6bolt? I noticed the rubber ring which 1g does not have.

You are correct, the tests were all completed for 2g thermostats. The equivalent Gates part number for the OE temp thermostat for the 1g is: 33489S

 

[1990TSIAWDTALON]

I have noticed because I am still a Chevy guy to, but now a dedicated DSM'er, that my Chevy thermostats appear to be the same physical size as our DSM units but I haven't tried them yet. I have a zip lock bag with 3-4 Chevy thermostats in it and they sure look like the same size in diameter. Maybe someone could try one of the 160* Chevy units (or I will) and give some feedback as to if they work or don't work. I will look again, I was thinking that they had a larger opening also for better flow, but it might have just been my eyes deceiving me. Just thought I'd throw that out there, if you are at a parts counter you might compare the two.

 

[chrysler kid]

I work a parts counter but I'll be honest, your hot running coolant temperatues in most applications have nothing to do with your thermostat. If your car is getting up to 210 with a 180 degree tstat it's going to get up to 210 with a 160 tstat. The better question to ask is what temperature do the fans kick on at. Its not like the 180 Stat affects how much water your pump is pushing past the radiator when fully open. You might as well not run a thermostat and just port the crap out of the housing but it's going to run 210 eventually


the thermostat just gets your car up to the operating temperature the car was Designed to run at. I will also state that I live in the south and I don't have winter so it's always going to be hot under the hoods here

The engine was designed to run at the most predictable constant temperature and has a thermostat to restrict cold coolant flow until it reaches that temperature.

 

[ThunderChild]

think of the thermostat as a EBC for your cooling system, tho the operation is slightly different. a thermostat doesnt get to temp and just stay open, its almost PWM because it will open, then close and re-open all relative to the temperature its designed to open/close at. the other part is the t-stat only has a certain size orifice to allow coolant through, like a metering system.
a colder t-stat will open sooner, in an attempt to maintain that temperature. trouble is, the fans wont come on till much higher, so if youre cooling system cant support that temperature without fans, theres no point really unless you live in a desert climate where its always 95-110*. even then its just a matter of time.

on the opposite hand, running too cold or w/o a t-stat could cause excessive warm up times or never fully reach operating temp, which would be bad. for drag racers it could be a livable change, especially with a filled block or smaller rad.