180 or 195 Thermostat

[c3po]

I had an issue with my 180 degree thermostat on my 1983 Chevrolet El Camino that no longer has any emissions equipment, the thermostats I have are the Robertshaw ones, the temp would go up to 180 degrees and then fall way down, I also had a little coolant seeping out of my lower radiator hose, made sure the hose was tight, thinking I needed to relieve some pressure I had a Robertshaw 195 thermostat and I drilled a small hole, no more leaks but what is interesting is the temperature goes up to 195 degrees and stays there, could it be that the 180 degree thermostat was bad because usually the temperature should stay in 1 place not go up to temp drop far down and come up again, wondering if small block chevy's just like 195 thermostats, my temp gauge looks like this 100-220-260, with the 195 stat it stays at the 1st 2 of 220, with the 180 stat it would barely come up to the 1st 2 of 220 and then drop down near the 100 mark and come up again, maybe by drilling the hole in the thermostat it is relieving pressure and before the pressure was so great it pushed so much coolant through that the gauge really dropped, since things are working so well do I stick with the 195 or go and get a 180 and drill a hole in it.

 

[Big Jim]

I think the 180 stat was bad.

I know that many disagree, but I believe in using the stat temperature the factory specifies. If you don't, you risk poor gas mileage due to the PCM thinking that the car is not fully warmed up and staying in "choke" mode much longer. Don't mess with the factory stat unless you have the ability to reprogram the PCM to compensate.

 

[c3po]

This car no longer has any computer controlled stuff, it has a carburetor on it, the only emission device is the PCV, think of it as a small block chevy from the late 1960's before all of the emission junk, I would think with it running 15 degrees hotter there would be less of a chance for deposits to build in the engine even though I am on my 2nd Maintenance Dose of Auto-rx, The more I think about it I think the 180 stat was bad, have had a few of these problems with 180 thermostats so maybe just stick with the 195 thermostat.

 

[Big Jim]

Wise choice.

 

[sciphi]

This is comparing apples to kumquats, but I recently put a 180 degree stat into my 1999 Buick LeSabre (without messing with the PCM) and can only say good things about it (knocks on wood). The stock stat is 195 degrees. I did check the new one on the stove first to ensure proper functioning before installation.

 

[c3po]

I have to warn you that putting a lower temp thermostat on a car that has a computer in it like yours can cause problems where the car's computer thinks it is running too cool and it can run a little rich, whereas my 83 does not have any computer stuff, that 15 degree difference could mean that you are not burning byproducts as well and you may run the risk of clogging your converter, it looks like you live in upstate N.Y. that 180 stat may be to cold for the winter, with your car the gas mileage may not be as good with the lower thermostat.

 

[sciphi]

I've gotten some of the best mileage I've seen out of the car with the 180 degree stat in. Granted that's summer driving. I will have to wait another 6-7 months to determine any differences in winter driving. I can get a re-programmed PCM to deal with the 180 degree stat, although that is more for performance driving.

Another reason I did it is to hopefully delay the degradation of the plastic upper intake manifold around the EGR port, a known problem on the Series II engines.