I've been running a 160* thermosat for a little while now and it runs real cool, whch I liked. But on the dyno, my air/fuel ratio was a low and it was suggested to me that 160* is too low ad I should run a 180*.

I thought running too rich and too cool also contributed to my stalling once and a while, so I've decided today to put in a 180* today. While doing this, I lost a little bit of coolant, and the thermostat seemed very long (it touched the bottom when I installed it). So to make sure everything was okay, I took the car for a 15-20 minute test drive and it almost overheated. It stayed at 1/4 before redline, and then started slowly creeping towards 260*. I took it back to the house and put more coolant in it, waited for about 5 minutes ad took it out again, no change.

Is this normal? I didn't think that 20* more would make me overheat, when with my 160* stat, I rarely even reached the half way point. Is something wrong, or should I jsut wait until the car cools all the way down with the new coolant in it before I test it again?

 

Sounds like you have not bled all the air out.

 

I knew I forgot something. I don't think I even know how to do that. It's late now anyways. I'll have to wait til tomorrow and try to bleed the system. Thanks shoebox.

 

His car is a 3.4. Do those need to be bled?

 

I think they (Summit Racing) might have sent me the wrong one. The thing was seemed too long, it fit, but the bottom of the thermostat touched the bottom of the thermostat housing. And that can't be right. It was about 2 to 3 times longer tha the 160* and the stock 195* thermostats I have in my garage. Also, I've never had to bleed it before.

 

Anyone know where the air bleed valve is on the 3.4?

 

my mom's '00 chevy venture has a 3.4. runs cool as crap. the thing only gets 1/8 of the way up on the temp guage. that engine sounds badass too.

 

What about the 180* stat being so long it hits the bottom of the thermostat housing, isn't that wrong?

 

yes

 

Well, I did miss it being a V6 . You may have gotten an LT1 thermostat by mistake. There is not a bleed procedure on the 3.4.

 

Someone told me to do this:

But that didn't work. The thermostat is definitely the culprit. This caused me a lot of greif and extra work. I might not even be able to meet my GF in time. Summit Racing shall feel my wrath.

 

That's pretty much a fill procedure for most normal cars not requiring a special bleed procedure.