Thermostat Question...

Hey folks,
I have a 95XJ 4.0, AW4, I am starting to have some heating problems. It is getting into summer time, and I live in the southwest. I just replace the waterpump (it was bad) and thermostat. I replaced the thermo with a stock 195F. Does anyone have any bad things to say if I replaced it with a 180F, not a 160F but a 180F.
Thanks,
Sean

I wouldn't go below the 180. The computer gets a bit fussy when you go below that. I've got a 180 in my 2000 XJ but I also have my computer modified. Even when I change the computer back to stock, I don't notice any significant problem. Mostly in the winter my heater doesn't put out a lot of heat.

A 180 is fine...the only problem is when the crankcase doesn't get warm enough to burn off condensation. With a 180 you shouldn't have any problems. But I wouldn't expect a 180 therm. to solve any overheating issues...sometimes it will disguise it, but the problem IS still there.

John

How old is the radiator? It might be going bad (plugged core). Or it could be a bad fan clutch or aux fan. Food for thought.

I have a robertshaw 180 tstat in my stroker. Works great.

K

What's the point? The purpose of an automotive thermostat is to keep the operating temperture UP, not down. The engine was designed to operate with a 195 degree thermostat. If it doesn't operate correctly with the correct thermostat, find and fix the problem, don't try to hide it with a band-aid solution.

Rock.Wgn said:

Hey folks,
I have a 95XJ 4.0, AW4, I am starting to have some heating problems. It is getting into summer time, and I live in the southwest. I just replace the waterpump (it was bad) and thermostat. I replaced the thermo with a stock 195F. Does anyone have any bad things to say if I replaced it with a 180F, not a 160F but a 180F.
Thanks,
Sean

Click to expand...

As Eagle correctly pointed out, you won't gain anything by replacing your new stock t'stat with a lower temp. unit. Some of us have 180* t'stats but thats only because we've added many performance mods or have strokers and we want to raise the threshold for the engine to ping.
If your engine overheats on the highway and runs a normal temp. in slow traffic, the likely culprit is a clogged radiator in which case, I'd suggest a 2-row Modine replacement. You could try flushing the whole cooling system first to see if that helps. You could also pressure wash your A/C condenser because the fins may be clogged up on the outside with insects and dirt.
If your situation is the reverse, either your viscous clutch in your mechanical fan is shot and it's not pulling in enough air, or your auxiliary electric fan isn't working.

I would recomend one of the hi-flow thermostats, Robert Shaw or Mr. Gasket. I think they are the same. Part of the problem with a lower temp thermostat is that the oil might not warm up enough, and not burn off any collected water. This is also the problem with short trips. Since you are in the Southwest, it probably isn't a big concern, but a northern climate it would be. Hesco also makes a hi-flow thermostat housing. I have one, but since I have run it and made a bunch of changes I can't comment good or bad about it.
Tom