New to YJ's...engine temp ? -
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Unread 08-18-2011, 06:24 AM   #1
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1995 YJ Wrangler 
Join Date: Aug 2011
Location: Wyoming, DE
Posts: 41
New to YJ's...engine temp ?

Hello all!! I will first start by sayin that I bought a 95 wrangler about 3 weeks ago and love everything about it so far! Its only the 2.5 liter but its a good start for me. I bought it on a Wednesday night and had it driving on the beach Thursday morning. I am very surprised how easy everything is to get too. I had to replace 2 exhaust/intake bolts that came out and I could stand on the front axle and work. Pretty cool. Anyway, let me stop rambling and get to my question. The PO of the jeep put in an electric fan a lower t-stat in and the engine temp never gets to 200 degrees. Right now where I live its about 85 degrees. At night when its cooler, (about 70 degrees) the temp will only just get past the 125-150ish degree mark. Obviously, its never good to let your vehicle overheat but is it possible to hurt the jeep by letting it run too cool? Sorry if thats a dumb question, I just figured I would ask.



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Unread 08-18-2011, 06:35 AM   #2
Web Wheeler
1991 YJ Wrangler 
Join Date: Dec 2010
Location: 14304 Niagara Falls, NY
Posts: 2,540
It won't cause permanent hurt that I can think of, but it won't run right either. The factory thermostat is set at 195 deg. and it usually reads about 210 on the dash gage. Worst it'll do is foul the plugs from running too rich (too much gas). I'm sure the computer will be a lot happier with the proper thermostat put in, and probably give better MPG's too. The thermostat is like any other unit, available at Autozone, etc. for 10 or 15 $.

Congrats on the new jeep!
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Unread 08-18-2011, 06:39 AM   #3
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1989 YJ Wrangler 
Join Date: Dec 2004
Location: Frederick, MD
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One drawback, at least in the summer, is that you may see a bit of a hit in fuel economy, (such as it is anyway!) , because the engine will be running at a temperature lower than the ECM expects to see when fully warmed-up, and it may richen the fuel mixture a bit to compensate. You may freeze your feet off in the winter!
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Unread 08-18-2011, 06:41 AM   #4
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1993 YJ Wrangler 
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^x2. to add to that, if it runs too cool, the computer will never come out of 'warm up mode' thus causing some issues. may not be major ones, but issues none the less. you're better off switching back to the factory 195* Tstat. though if over heating is a concern, you could search the web to see if theres a hi flow one out there.

happy trails!

EDIT: Biker beat me to it ha
If you can't be safe be deadly.
We are what we repeatedly do. Therefore, Excellence isn't an act but a habit.
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Unread 08-18-2011, 06:42 AM   #5
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1989 YJ Wrangler 
Join Date: Apr 2008
Location: Detroit, Michigan
Posts: 14,964
If the engine doesnt get warm enough it will not go into closed loop on the Engine controller (ECU). That will cost you some $$ at the pump because it's not running as effeicently as it should without the O2 sensor being used to feed back the fuel level in the exhaust. Read through a few post about the thermostat housing. Its a little tricky with the thermostat. It likes to slip when you are putting it in and if you crank down the housing bolts it will crack the housing. They are also a little pita to get sealed.
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Unread 08-18-2011, 06:56 AM   #6
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1995 YJ Wrangler 
Join Date: Aug 2011
Location: Wyoming, DE
Posts: 41
Awesome, thanks guys for the quick replies. I did notice the t-stat housing looks like it may be tricky due to the fact that it is sideways haha. I will read up on it so I make sure that when I change it out, I will do it the best way possible. Thanks again!
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