and now for something completely different
 

Hello chaps. Need some help with this noise I'm getting after starting the car...I'm hoping it's not the dreaded chain tensioners. No codes at all.

Listen out for the clanging noise after 25 seconds our so, happens a few times again before the end of the video. It seems to be coming from the passenger side of the engine.

Video was uploaded to youtube:

YouTube - ‪XJ8_2002_noise.MPG‬‏

Any thoughts/tips will be appreciated!

wow -- that is loud. My "R" is very quiet. Unless -- that is some form of feedback.

It sure sounds like upper end noise and the first thing that would come to my mind would be the tensioners -- and if that is the sound of the chain slapping around you do not want to start it again.

This is a known fault and failure is fatal -- don't play with it.

The fix is relatively cheap.

The camera's audio AGC has a lot of gain so it's sounding rather loud, but smooth none the less.

All I hear (other than a reasonably decent idle) is an occasional loud CLICK from the AC compressor clutch engaging/disengaging - at 0:28, 0:36, 0:46, 1:01, 1:06, 1:35, 2:03, etc. Sounds normal to me.

Am I missing something obvious?

Agree with Quad, sounds like the a/c compressor. Turn the a/c off and see if the noise is still there.

Thanks all. AC is off in this clip, it sounds to me like someone tapping a piece of thin metal. The car has a manufacture date of 10/01...would that mean it has the newer tensioners?

Hello again. I found the original paperwork for the car and the engine # is 0108290653 which I believe means that this car should have the metal tensioners - correct? I'm going to take the car in this week, but the more I listen to it, the more it appears to come from the dead center to rear of the engine (not where the timing chains are).

Ouch.

Use a piece of small diameter tubing, one end stuck in your ear and the other slowly moving around the engine compartment, to locate the area from which these clicks are emanating... if it's not the AC compressor (but it sure sounds like it) then, perhaps, its a relay turning on and off - and they are all in the rear half of the engine compartment, on either side of the engine.

BTW, even with AC off, there appear to be some scenarios in which the compressor will still cycle.

Ok thanks, will check it out.

OK, this evening I swapped the relays around for the AC compressor clutch and the noise virtually stopped. It happened twice in a 3 minute period..not every 15 seconds or so as before.

So remove the AC compressor relay altogether and if the noise stops completely, you know the sound is the AC compressor cycling... then the only issue you have is to find out why (which is a hell of a lot less stressing that wondering if your engine is self destructing, LOL).

Just shine a flashlight on the a/c compressor and if the noise happens as the clutch at the front of the unit engages with the compressor body then you have found the scene of the crime.

Duuuh... SO much easier than removing the relay. I get stuck in the engineering world too often.