Been thinking my 0331 head is cracked or my HG is bad because my 4.0 was drinking some coolant.There is a little bit of creamer on my oil filler cap also. So went to hardware store and bought 5 quarts of oil went home and cracked open the oil drain plug and let er' drain. i come out 20 minutes later and there is a nice layer of coolant on the bottom of my clear oil catcher pan. Im perty sure im gunna be ripping into the engine soon.. second vehicle i have bought with a blown HG. i have awesome vehicle buying skills i guess. Can anyone suggest/confirm anything for me? I just bought this Xj a month ago damn it. my oil pressure is doing the 0 PSI at idle when warm thing to. runs at 40 PSI until warm. then it drops to 15-20 when cruising at any speed and at idle or low RPM it drops to 0-10. Oh any my rear pinoin seal has begain leaking.

2001 XJ I6 177xxx

Sorry for long post lol, any help is greatly appreciated!

 

More than likely the head is cracked and the bearings have been wiped out...
Time for a replacement engine or a new head and have yours freshened up.
Verify oil pressure readings with a manual guage just to be sure.

 

i have replaced the oil pressure switch. and i have a little bit of oil coming from the very bottom pulley in the front of the motor. so you are saying i need to rebuild my motor Rmart? this is the first time i have pulled coolant from the oil. so it has not been in there long. maybe 2 weeks. it seems to run sluggish sometimes but other times it runs like a beast, i just dont get it :/ my 4.0 is weird lol. And i just got my 2 inch budget boost today lol. Rocky road makes some beefy shackles.

 

Pop the valve cover and look for cracks between cylinders #3 and 4.

 

I am almost certain the pressure allowed by jeep is between 35 and 75. mine runs at 30 to 50 depending on the day and has done so since day one. with yours being so low and the coolant issue, I would rebuild as soon as possible.

x2^ on frankz's response, late models 4's are notorious for a weak part in the head, but it's kind of a crap shoot as to if you have a weak head or not. I would guess you probably do. Sorry about the bad luck man.

 

Ya th 0331 Head was used in 2000 up XJ and they have a weak spot between #3 #4. they had to add more nickle to the casting or something later on.the oil pressure has been low since i bought it. They told me they had it checked out and it was the sending switch. replaced it and no luck. Thank you guys for the help.

 

The oil pressure at warmed up temp. is between 10 and 15 psi. (some of you guys better catch up on your reading it helps you to answer right).Roughly 10 psi per 1000 rpm. Try draining again after you run some junk oil like valoline pensoil,etc through it then refill with good oil,and a can of stp,and see what happens, my head cracked also but i caught it right off, so give it a shot.

 

OK, i pulled the valve cover a minute ago and snapped some pics. My XJ needs to go a little easier on my wallet and the creamer lol. Found that creme like substance on my oil filler cap a couple days ago so i new it was gunna be in there. I could not make out a crack in between #3 and #4 but im gunna rip it apart and have the head magnafluxed. Am i missing anything here guys? Oh ya, The head im going to get if it is cracked is a reman. with a three angle valve job, what is the benefit of this? and YES i have used search lol.

 

pic upload

 

Where is the pic?

 

grrrrrr idk why but it won't upload right, i have tried three times. And what is really cool is im a computer repair tech LOL. I guess im just stupid. Gunna have to click.

http://img508.imageshack.us/i/dsc00555m.jpg/

http://img684.imageshack.us/i/dsc00556zm.jpg/

 

Got a pic of the head? Take it between the 3rd and 4th cylinder...

 

already put the cover back on and forgot to take a pic of the head. Sorry lol. i might take some pics when i rip it apart hopefully this week. is there anything i can do while i have it apart that will help the motor a lil bit. i was thinking of getting a bored TB Tb spacer and all that. i have cat back exhaust and an airaid cold air on it now.

 

A tb spacer wont do much for your engine, save your $$... They only get gains on TBI engines.. About all they do for our style is make a whistle..... Go on JF and search on there.. Actual dyno tests proving it....

 

Ya i have heard that before. One of my buddies swears that they do lol. thanks for confirming that.