Cooling System Thermostat

At least 192 or 195.

The hotter the better for interior heat.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Jack Dow wrote:

Get the standard one (192??) A lower one will not let the engine warm up to a good operating range for fuel economy. Your '89 has a temp sensor that should sense full temp and tell the computer to go to closed loop. IIRC, that sensor kicks in around 160 degrees so you MIGHT be able to use a 180 degree thermostat if you have some other problems.

Consider doing a full drain, chemical flush agent, power flush, and refil with new antifreeze. Takes a couple of hours, does wonders for better cab heat, lower engine temp, etc.

Cheers.

Jack Dow wrote:

I just bought one for my '85 four weeks ago, and tried to buy a hotter one (trying to get more heat from the heater), but the standard 195 was all that was available. With my three-row heavy-duty radiator, too much heat has never been a problem.

Many will tell you that hotter (195) is better because vaporization is better.