Internet Engine Noise Diag... are you ready?

Okay, so I bought a 93 XJ with4.0L HO, 280,000 kms (Canadian) which converts to almost 175,000 miles. I'm hearing a light knocking cold, warm or hot... coming from the engine... a light but kinda deep "knock knock knock"... ongoing until about 1500rpm when it goes away.

Not too familiar with the pushrod engines... I work on VW's all day long. So....... any thoughts on this one? I'm thinking either timing chain or bottom end noise.... but some of you guys who have had these 4.0L's for a while may have a closer idea.

Thanks in advance!

Kelly

Anyone?

If it's a deeper sound it could be bottom end. See if it's more pronounced from the oil pan or the valve cover. If it's top end it's typical for a 242 with this mileage, if it's bottom end then you may want to think about doing bearings.

In canada do they call him Kilometers Davis?

Could be piston slap, but listen and see if sounds like it is coming from the back of the engine, a cracked or loose flexplate can sound like a bad lower end.

dizzymac said:

Could be piston slap, but listen and see if sounds like it is coming from the back of the engine, a cracked or loose flexplate can sound like a bad lower end.

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Yeah, I've heard these 4.0L's are piston-slap-happy...

Thanks for the tip...