Hello all. Knock from drivers or left side of engine when looking in from under hood. Seen several Land Rover and Jag threads that have all said many different things about what it could possibly be. Exhaust resonance, Chain tensioners, maybe Variators or VVT sprockets I’ve seen them called. None of those threads came to a conclusion. So I’m curious if anyone’s nailed this issue down yet.

Only when engine is hot and if it sits for longer than 15-20 min depending on temps outside no issues at all. Car is well service and only has 16k miles.

thanks in advance!

 

Car is an 2011 XJ 5.0

apologies for not listing above

 

Many different causes so you need to study your car and find out what it is.

Have you checked for codes?
Have you checked the tensioners?
When do you hear it? At idle or going down the road?

What oil are you using and when was it last changed?
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Tension seems fine while peaking through the oil cap compared to my knowledge of other engines I’ve built/repaired

oil is fresh liqui moly 0w 20 the JLR spec stuff done maybe a month ago

no CEL haven’t scanned no running issues or performance issues to make me think it would be necessary although I can on Monday when I return to the shop

 

Noise is only at idle disappears with any fluctuation in rpm or as soon as you set off

 

post a video

 

video

 

It is a knocking noise, but it doesn't sound like an alarming metal on metal knocking noise that would be coming from inside the engine. At times in the video, it almost sounds like a puffing noise.

If I were you, I would be tempted to loosen the belt off the crank shaft to see if it's belt-driven accessory related in an attempt to narrow it down. That's easier to do on your car since you don't have to deal with a supercharger belt as well.

 

"Only when engine is hot and if it sits for longer than 15-20 min"
"Noise is only at idle disappears with any fluctuation in rpm or as soon as you set off"

I have the exact same problem you describe only difference is the noise on mine sounds faster yours sounds slower probably because of the engine size mine is a V6 supercharged yours a V8
Check your oil level mine was low 1 liter due to Vacuum pump leak after top up the noise reduced by 50%

 

Noise reduced by 50%? Did you ever get it to go away?

when the cars off for 5 min the sump should be full I would be very surprised if it was a low oil issue?

also if you read on some I said if it sits for 15- 20 min and cools properly the noise is gone. it’s only on a hot start

 

Of course I’ll double check the level and for leaks thanks for the tip.

 

15 20 mins the engine is still hot No? unless you live in Alaska

No I never got the noise to go away completely only time its not there is during cold starts

Low oil could be lubrication issue for a worn part inside the engine

Mine has to sit overnight or at least a few hours for the noise to be gone if the engine is even slightly warm the noise will be there still I think we have the same problem

 

It seems for mine 20 mins is long enough on a cool day.

when the cars hot like that the sump should be full very quickly after shutting down ? Given the weight of the oil especially. A low oil issue would likely present itself maybe on a grade or after some good curvy roads ? Not ruling it out just seems odd