Not overheating...but running warm

[yossarian19]

5 ppm is the rule of thumb, though most that I've even thought to test were 30 or more ppm of hydrocarbons. That's when a customer comes in saying "yeah, it got pretty hot and now it doesn't run right". At 5 ppm, it's a very slight leak.
I'd try some head gasket or block sealer & follow directions exactly. I've got limited experience with the stuff but on the one car I applied it to, it seemed to work.
At $15 or under and an hour or two to try it, what have you got to lose?

 

[Boss Cherokee]

The fan did slowly spin to a stop with the motor hot. I just finished putting the ZJ clutch in and did the same test drive.

I am wondering my XJ is a 95. I purchased a ZJ fan from a pic a part but it is practically new. The fan appears bigger diameter wise than the original! It does appear to have more resistance than my factory one! It has a big nut on it where it would attach to the engine mount but the engine mount appears to be a 4 bolt bolt on flange! I have not pulled the old one afraid only to have to reinstall it!
Sin Any comments!
I have similar temps and similar issues as pipe wrench so I thought I'd keep the post going to help others as well.
95 4.0 auto dblr 231/300 4.56 36''x15.50x15. trans radiator eliminated only running thru dual pass Deraile cooler with it's own 10" fan.
I can not believe it's the CAT since I pass smog without issues every 2 years! NO codes. Radiator clean was replaced 4-6 years ago but less than 6000 miles on it, water pump new with home made impeller shroud. New cap, new thermostat!
Has boiled over once or twice but does not show head gasket symptoms. I will pressure test today, aux fan works and comes on at temp.

 

[yossarian19]

My first thought is "lose the impeller shroud".
Is your ZJ fan clutch from a V8 or a 4.0? I didn't have any large / centered nuts on mine...
Running 4.56's and 36" tires, you are taxing your cooling system a bit. I'm not saying you don't have any other issues, just that yes, the engine is working harder than the engineers designed for.

 

[Boss Cherokee]

Thanks I figured as much. The Fan may not be a ZJ 4.0 but a V8. I got it about a year ago and can not remember! So I take it it must be a 4.0! Shame the clutch is tight! My fan clutch is spinning 2-3 revolutions after I shut off the motor at running temps (210*)

 

[yossarian19]

Yeah, it has to be a 4.0. A new clutch is $55 at Napa where I got mine. Not free but not too bad, either. From the sounds of it, a new fan clutch should be in your (near) future. Loose clutch = less airflow = less temperature drop across radiator at anything under 30 mph.

 

[Boss Cherokee]

Thanks Y19 I will change out the clutch. Last thing if there are 2 choices such as heavy duty or regular and/or a specific name brand that's better please let me know if not there is no need to reply! Thanks

 

[yossarian19]

I'd go with NAPA or Hayden. Supplies / odds & ends I'm finding Autozone and Oreilley's to be fine... for parts that need to work as designed, NAPA.

 

[Boss Cherokee]

Bought the XJ clutch fan today from O'Reileys $36.00 but as I walked out of the store I thought about switching to ZJ part. I went back in and checked it was a different part # so I ordered it and will compare it tomorrow. The ZJ model is $56.00. The Xj part seems cheap tin but it was a Hayden part! Ifind out tomorrow!

 

[Boss Cherokee]

I received the ZJ clutch today and WOW! Compared to the XJ part, both being new side by side! The ZJ is hands down superior. I was tempted to test the two by welding up a bracket with a nut to check torque resistance but I wanted to get it on before dark! I test fired the Jeep and at idle it stayed at 205ish stomped on it for 20 minutes or so up and down 1/2 mile of 6%+ grade and after 20 minutes the secondary fan finally kicked on! I am looking forward to the heat this weekend to try it out! I did power spray the condenser and radiator while I had the shroud out but it appeared clear of dirt and grease. The water pump and accessories mentioned are 6 months old with a shroud on the water pump, new lower hose, thermostat, cap and anti freeze.

 

[yossarian19]

Yep, that's why I like my ZJ clutch too : the electric becomes a "once in a while, when needed" fan instead of an integral part of the cooling system. My regular driving habits, it won't *ever* come on until ambient air temps are 90+.

 

[Boss Cherokee]

thanks for bringing it back up! as I said I had bought a ZJ clutch but obviously the wrong one from pick a part! Ive had for near a year and realize now what a differance it makes. I stoppedrunning my 85 XJ with the V8 because of eat issues in summer weather due to a 60 over bored block. I was fed up and stopped wheelin then i built up my this 95 only to have similar issues but this was too easy. I am recharged and will start some new changes such as new arms to replace my radius arms. Thanks again for the suggestions! Sorry fat fingers small keyes!