better t-stat?

[jimgrms]

will tylenol work????

 

[Yucca-Man]

I'd second the small hole a 12 o'clock. But with a 195 thermostat. The motor runs at or close to 210 all the time when it's working correctly.

 

[collkid]

With it having a 180* t-stat in it already, I'd be more concerned with if it's stuck open and not allowing the engine block to build heat.

Secondly, see if you can get a liquid thermometer and test the actual temp of the coolant at operating temp and double check that it's not reaching 180*.

I wouldn't want a higher temp t-stat in an XJ with a 4.0.......

Isn't 195 Stock?

I ran a 180 in my old Jeep, twas a dumb Idea, didn't get hot enough and the heater sucked and got worse MPG.

 

[YELLAHEEP]

Isn't 195 Stock?

I ran a 180 in my old Jeep, twas a dumb Idea, didn't get hot enough and the heater sucked and got worse MPG.

Well after consulting Google I've confirmed that 195* is stock for the XJ's. Initially I assumed 180* was and figured that was a good thing to stick with to manage over heating issues. I guess when I've replaced t-stats inthe past I didn't memorize what degree rating was going in......

I wouldn't have thought 15* difference would cause a "cold" engine/heater condition but I've never had an XJ engine run "cold" either.

So yeah I suppose Mike would likely be fine with a 195* t-stat.

 

[Hypoid]

I wouldn't have thought 15* difference would cause a "cold" engine/heater condition but I've never had an XJ engine run "cold" either.

So yeah I suppose Mike would likely be fine with a 195* t-stat.

Yup! Not to mention, engine temp affects more than the EFI parameters:

The SAE ran baseline engine and fuel consumption tests. They are published in SAE manuals that you can buy for $$$. I was lucky enuf to have access to them at a place I worked. There is one manual I would dearly like to have if anyone has a spare $400 that they want to give me... Anyway- The baseline for engine wear was picked to be 180°F for the SAE tests. For every 10°F under that temp engine wear doubled. So at 160°F the engine is wearing at 4 times the rate as it would a 180°F. The paper did not go into higher temp applications but it follows that engine wear is probably halved at 190°F. This wear rate is caused by a chemical reaction that occurs at the cylinder wall that erodes the cast iron surface. The resulting particles of cast iron that are released also abrade the cylinder walls. The rings, bearings, and other engine components also wear more rapidly due to these particles carried in the oil. An oil filter only removes a certain % of the particles on each pass (called a beta ratio by filtration Engineers). So the more particles produced the more circulate in the oil. Each particle abrades all of the surfaces it comes in contact with and produces more particles. This wear mechanism does not have anything to do with the oil film. The fuel consumption per brake HP also increased at temperatures under 180°F but I can not remember those figures. You can see the effects of engine coolant induced wear rates on many inline-6 engines where the #1 cylinder has a much higher wear rate than the rest of the cylinders. Check a few of those engines in the junkyard and feel the ridge on #1 and compare it to #4,5, or 6... Increased engine temps are just one of the reason we see higher engine life from newer engines. Even higher engine temps get into other problems with material breakdown and degradation.

Reference cited: http://www.ford-trucks.com/forums/showpost.php?p=2079702&postcount=41

I'll be testing that observation about cylinder wear.

 

[in4aride]

ya well all they had anyway was a 195* tstat anyway. got it tossed in but havent had time to do much else as im getting ready for tonights fun

but we will see how it goes

 

[in4aride]

musta done something right, jeep warms up to right about 200, then drops about 20* then goes back up no problem.
heat is a whole lot better too and was definitely well worth the tstat change
thanks for the input guys :thumbup:

 

[Yucca-Man]

Did you drill it before installing it? Or do the aspirin thing? I learned the drilled t-stat years ago made a big difference in resolving many of my heating/cooling problems.

 

[in4aride]

i did

 

[Yucca-Man]

:thumbup: