Howdy folks! I'm Sam and my wife Tracy and I just picked up what we hope is a good '01 XJ. It's pretty clean and has 161k miles on it and seems to be in pretty decent shape. The day after we bought it we're driving it around (for much longer than the test drive) and noticed the oil pressure was 'low' - didn't notice it on the test drive, but the gauge showed low enough for the [CHECK GAUGES] light to come on, which was awesome. Bought a new pressure switch at the local parts store on the way home, installed it, and the gauge was reading better - lowest pressure hot at idle in gear was 13psi or so, which as I understand is the factory spec, so 'good'. Then...noticed the water temp wasn't actually getting up to spec (195*) - was just hovering around 150 or so, so I thought the thermostat was stuck open. Was also a good oil leak right under the pan. So, pulled the thermostat housing, removed the 180* unit - and it looked cockeyed too, and put in a 195* unit. Pulled the oil filter adapter and replaced the three O-rings, which cured the oil drip, and the engine now gets up to the proper temp.

Two things still going on - when cold the engine seems to have what sounds like a couple lifters clunking around...but when warmed up it's nice and quiet. Also, the heat isn't really 'hot' - it's 'warm' - was like this before and after r&r'ing the thermostat. Flushed the system and heater core when I changed the t-stat so maybe the doors aren't fully closing - dunno, but I think the heat should be 'hot' and not 'warm'.

Weird thing is...the oil pressure is actually getting 'better'. It was 13 psi hot in gear at idle/40psi at 70 mph...and now it's around 19psi/45 psi at 70 mph, before and after changing the oil to 10W30 Rotella T4. Not that I'm complaining...but I guess the pressure switch/system is 'healing' itself. I just wish the minor internal tapping (sounds like lifter clack) wasn't there at all...but it does go away for the most part when fully warmed up.

So, could things to iron out, but otherwise it runs and drives pretty nicely, and should serve us well. Doesn't seem to be exhibiting any of the tell-tale signs of a bad cylinder head, and hopefully it just won't, but if it does we'll r&r that too.

More to follow, most likely in the technical/driveline threads.

Cheers!
- Sam

 

Welcome to the forum and XJ ownership!

The stock/technical section may be where this answer needs to be moved to however:

That lifter noise has been heavily debated on CF but here’s what I’ve gotten from it and what I did although I never experienced the noise other folks do or my ears aren’t sensitive. I think any of the Rotella’s are a fine choice, Dino - Blend - Full Synthetic.

Before I changed my old oil I put Chemtool B-12 in the cold crankcase and let the Jeep idle for 20 or so minutes, then I immediately changed the oil/filter and used Rotella T6 5-40, 5qt and 1qt if Marvel Mystery Oil.

I drove that for approximately 1000miles and did it again, twice.

Finally on the last oil/filter change I used 6qt of Rotella T6 5-40.

Some people say that they got bad leaks from the B-12 (or any crankcase flush) or switching to synthetic. In my case I didn’t cause any leaks, maybe I got lucky.

My oil pressure stays steady at 40psi since I’ve done this, it may not have changed I just didn’t pay attention to it before I started reading more on the forum about potential lifter noise/cures.

Hope this helps, happy XJ’ing!

PS- Where are you at in Colorado?

Eric

 

I highly recommend a factory Mopar oil pressure sending unit. The cheap replacement units you get from auto parts stores can be very inaccurate.

Mine was reading 9psi at idle and barely ever above 20. I replaced the offbrand with another offbrand and it was even worse. I was worried I had a major issue on my hands so I tested the pressure with a mechanical gauge then installed a Mopar sending unit and they both matched up almost exactly at 16psi idle and 40+ after 2000rpm

 

thanks for the info Eric. Question - why did you do the Chemtool flush? Was it to 'flush out' the oil passages inside the lifters to ensure the oil pressure could re-fill them with new oil, etc?
We're in Falcon, CO - just on the NE side of Colorado Springs.

 

Thanks for the info - I had planned to verify my oil pressure with a mechanical gauge as well - just haven't got that far yet, and I'll report back once I do - hopefully it's close to what the pressure unit I installed is showing.

 

Truthfully I watched a YouTube video of a guy using it, then I went to their website and one of the people that works there posted a blog post about using it in the crankcase. The product is marketed as a fuel system cleaner.

In my mind my engine is “cleaner” now and I’ll do it again maybe once or twice a year.

In other words I didn’t have a specific problem I was attempting to solve I just read about it and went for it, and I decided I definitely think it helped.

-Eric

 

Since you have to remove the sensor to check when I got around to doing mine I had the dumb idea to do this:



I plumbed in some fittings so I could check it whenever I wanted with out removing the sensor.
Also I could see how my cluster gauge compared with the mechanical gauge.
Having an '00 I like to keep an eye on things.
That is at a very hot idle and pretty much read the same as my cluster gauge.
I used thread sealant where necessary. Thing is since I set that up I have not done it again.
So I am hoping that getting that bolt off in the capped off port will not be to hard. LOL.

 

all good, no worries - I'd thought maybe you had lots of lifter noise or such thanks again

 

...not sure I'd call that a dumb idea Thanks again

 

Mind=Blown, I didn’t even know you could do that!

-Eric

 

I have the part numbers for what I used in my files if you need them.
Pretty sure everything was 3/8"-27 NPT.