Join Date: May 2004
Location: Southington, CT
A couple summers back, I replaced my thermostat along with my radiator (rad was missing about half its fins). Unfortunately, the t-stat I got must've been of the really cheap variety, now that I'm driving it in the winter I'm suffering with poor heat and a vehicle that won't get to temp properly under low load.
Symptoms: Temperature comes up to the 210 mark on warmup, then drops to what I assume is 155 (midway between 100-210), then comes up to just shy of the small hash to the left of 210. If I get stuck in traffic and start moving again, it'll drop to near 155 and crawl back up to just shy of of the small hash mark again. As an aside, what does that mark indicate? 182.5?? During the summer it runs at that mark pretty much all the time, which I find strange since I thought the 4.0 was supposed to have a 195 deg F thermostat, which shouldn't run this cool if I'm reading the gauge correctly.
It seems my thermostat is opening too much at the low end of its operating range. My dad's YJ with the 2.5 behaves similarly with a similarly sourced t-stat. I don't think mine's defective, just poor quality. The one that I replaced behaved well, no idea where the PO got it. Could've been factory original for all I know. I should've left it in apparently.
Where do I get a good t-stat? What are the brands to get or avoid? Should I just go to my local dealer? Quadratec sells an "Omix-Ada, Inc" t-stat for a premium price. 4wd.com sells an "offroad only" 195 deg thermostat. No explanation of why it's "offroad only" though.
Any tips? Go factory or go home for a quality thermostat? Seems a silly thing to have to go to the dealer for, but I will if it gets me what I need.
1995 YJ, 5spd, Forest Green, 4.0L, off road package, soft top, 230k miles and counting