engine noise

I'm new to the XJ, and to your forum. I bought my '99 about two months ago. Ok after reading the 22 pages of "Your oil recomendation" I thought It would be a good idea to change the oil not knowing what the PO used. I used M1 HM 10-30 and a mopor filter. Now when I start the jeep after it has sat for awhile there is a noise, sounds like some sort of chatter coming from the engine. It gose away after it starts to warm up. Is there anything I should check or should I have gone with a thicker oil. Oh yeah.... it's a 4.0 with 61,000 miles. .

Nice engine with on 61k! Shouldn't be a problem for another 190k, however you never know what the PO has done with it. Make sure you have good Oil pressure like Retep said. Other than that you should be good. Glad to have you.

--Alex

Thanks for easing my mind, next oil change I will run thicker oil. I've seen people doing seafoam treatments, what is that and should I look into that at or befor my next change? By the way the oil pressure is about 55-60 cold and around 35-40 warm and at idle. Ok?

Hi, there! I'm new here, and a proud owner of a -93 XJ LTD with a 4L High Output engine. I've had the car for about 6 months, and I have some chattering in the engine just like rehberg79 describes. The difference is that the sound comes from somewhere in the lower rear end of the engine, and occurs when I put the car in reverse and turns the wheel. Any ideas? The car has approx 187k on the clock and the oil is new.

That oil pressure is great, rehberg79. The noise might just be a little valve noise. As long as it isn't overheating you should be alright ( in my non-professional opinion) cause it takes a long time for thing to wear cold, but when things get too hot, it wears real quick.

Muddy-93, yours sounds a little bit worse. I bought my '90 Xj with an engine knock. It drove fine short distances from home to class at most like 4 miles. But when I went home for the summer the first 30 miles of 100 did mine in. I had a spun bearing which was tearing up the crank. and then connecting rods had a gap worn so they were getting jolted with every revolution. Not bad during idle or light load, but when I hit 70 mph it started getting f-ed up. I was losing compression since the thing was way over heating and the rings werent sealing I suppose.

Not a good thing either way if it's a bottom end noise. Might try having the connecting rod and main bearings changed. Have the crank checked for roundness and in the tolerance specs while it's out. You might have it ground if it's out of spec, and install oversized bearing with it. This is no small weekend job, however it wouldn't be too terribly difficult with the proper knowledge and a good friend to hold the crank up. I would do it myself to mine, cause I really don't mind having the XJ out of commision for a few because I have a backup ZJ as my parts getting car. A shop should do it if you are a novice / newbie.

When you say it's only when in reverse and while the wheel turns, you have me stumped. sounds like a power steering pump if its when the wheels turn. Is it a knock, or ping, or just a "I turned the wheel too far and the pump is squealing" sound? Is the sound in time with the engine rpm's or is it at its own pace.

Maybe post a video of the sound and where its coming from?

Let me know if my novice knowledge can help.

--Alex

No, the "I turned the wheel too far and the pump is squealing" sound I know. This is more like a "Dragging a small chain over a table-edge" kind of sound. The engine purrs like a cat most of the time. Only when it is cold (below freezing), it rattles violently for a few seconds. This rattle dies gradually down to a clunk every minute or so, until it stops completly when the engine is warm.
But the "Dragging a small chain over a table-edge" sound I have even when the engine is fully warmed up. Weird, right?:wierd: