I installed the HD fan for more airflow when driving in deep sand. The improvement to the AC while idling was a side effect. Regular duty would be fine for normal conditions, considering the cooling system is in good working order and the air passages through condenser and radiator are clear.
Seems a common issue is silt and crud buildup in the cooling systems of our aging XJs.

 

Yes. Fix it before your starter gets ruined.

 

Yep

 

Could it be from your oil sender?

 

It's actually clean around the sending unit, so it's gotta be the adapter o-rings. I did think that though. Really just hope it's not the rear main on top of this. I'd prefer to not dig into that project.

 

Ever read this?




I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.

Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?

A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.

First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.

Revised 02-26-2013

 

I dream of one day owning a 4.0L that doesn't leak oil. I know it's possible, but all of mine have. Right now I have a 5.9L that burns more than it leaks, so I'm on the right track

 

^^^Sure have, and so far I'm down to the oil filter adapter seals. No wet spots around the valve cover, like just mentioned, nothing around the sender unit, so adapters next. Since there's oil running down the bottom of the oil filter, I hope that's my end point, but we'll find out once I get the seals replaced. Thanks for the assistance!

 

I swapped the steering from my ZJ to the XJ(since it was all brand new, and it's parked), the drag link collar is bottomed out to get the steering wheel straight. What's the best way to figure out what part of the steering system is un-aligned? The drag links are the same part from ZJ to Xj right? Can the steering wheel even be off? I replaced the clock spring and it looked pretty much impossible to screw up the alignment there. Does that mean someone had the pitman arm off at one point?

 

[QUOTE=salad;3257703]To check spark, you need one, or several, of these guys:



As for the crank-no-start, you might have a fuel leak somewhere, sure. Pull the plugs and see if they're wet. Wetness would indicate a slobbering injector. May also be a check valve, but if it shoots up to 48 immediately when the key is turned, a leak isn't terribly likely.

What other troubleshooting has been done? Have any electrical connections been refreshed? Are all fuses and relays good?

Do you own a scanner?

XJs are very reliable when taken care of. It doesn't take much to keep them in good shape, but almost all of them have been abused and neglected.







If 42 lbs. residual is enough pressure to start, I guess I'm chasing spark. I used to have one of those lights, looks like I might need another. So, I take the coil rail off to expose the plugs and test from there to the plug tip? Sounds awkward but I'll give it a shot. I have to pull the rail to check plugs anyway, I found the meter test proceedure for the coils also. I'm going to test the tps today, found a good clear thread on that, then start looking for crank/cam sensor test threads. I really don't want to start replacing things, the crank sensor looks like it'll really be a pita to change without being pretty sure it's bad first. I need to get under there with a mirror anyway to check the harnesses for rat damage, not unheard of around here.
I have an OBD scanner, it pulled an old #3 misfire code (from heat sink problem) I erased that and it didn't come up with anything new, so I'm pretty sure it's working. The guy I got the jeep from seems to take good care of his rides, lots of new stuff on it and everything working great till now. Fuses and relays are the first thing I checked, I just put a sub under the seat before it decided it wasn't going to start, I backtracked and disconnected all that thinking I might have shorted something and blew a fuse

 

I read somewhere that the ZJ drag-link is slightly longer than XJ.

 

what do you have a 5.9 in?

 

in his sig:
1986 Jeep J-10, 5.9L 360, TF727

 

Thanks for the feedback - I think you are right as far as removing the radiator.

Wish I didn't have to - I think I am going to try and use the shortest "screw" and use a nut or bolt as a spacer to give the puller enough length to get the harmonic balancer off the shaft, without being too long and requiring me to remove the radiator. Worst case I will just drain the coolant and remove the radiator, but it adds like 1-2 hours to an otherwise simple task.

I am going to make a how-to as there really aren't any good how-to's for a timing chain replacement for the XJ. Tons for the Wranglers but not for the Cherokees it seems.

 

I'm on the app so can't see signatures, thank you