Hi all... I'm new to the forum, and to my 2001 XK8.

Please listen to the sound in this video, and let me know if this sounds OK. Right around 2000 rpm you hear an increase in the noise level, that clears up around 2500 and above. 100,000 miles on the odometer.

http://www.myrq.com/myxk8soundcheck/xk8sound.wmv

Naturally my first concern was chain noise, but the sound does not seem to come from that area. Anyway, I am going to be changing the upper tensioners in a few days, since they are the old plastic ones.

Thanks!

 

Man, 23 views..... Nobody has their speakers turned on? Just kidding.

I thought it sounds weird at about 5 seconds into the video. Hopefully this is normal.

 

Sounds like a bags of old nails, just as mine was. I was one tooth out due to one tensioner losing its plastic foot.

Good Luck

 

I say the chain. You should be looking at your tentioners and refrain from running it until you check them.

 

Well, I had the valve covers off and the chains felt tight (by that, I mean no slack at all) and tensioners themselves looked fine. I looked closely to see if the plastic was still intact on both ends, to the extent that is possible while they are in the car of course, and they didn't look like they'd be causing this sort of noise... I realize of course that appearance isn't everything. I'm changing the secondary ones this week. So, you are very confident this is the chain making this noise, eh? Any other possibilities? Thanks again!

 

I listened, but not knowing what chain slipping sounds like, I can't make a guess. But, it is very plausible. I just wanted to say thanks for the vid w/sound, it sooooo makes a difference instead of trying to words to describe 'rattles' 'noises' and such.

Its only been a day, remember we don't have thousands of members online at any one time, so there may be more viewers later on.

 

Did this get fixed? mine does not sound like this tapping but has that back ground metalic dull sound that goes up and down with the revs very similar.

Kevo

 

Not fixed. I changed the tensioners, no improvement. I still have not found the cause or source of the sound...

You can hear it at 6 seconds into the video at the top of this thread, not the usual valve and injector clatter. It is hard to describe.

It appears to be coming from the "top" of the engine, sort of near the intake manifold, not from the front.

So, we've just been driving it without incident. The sound mostly goes away after the engine is fully hot, say, 10 minutes after starting.

It only happens as you rev UP, through 2000-2500 (ish) rpm, not on the way down. Revving it up gradually/gently while in park is when you can hear it the most. Once you get below or above that rpm range, you don't hear it.

Does anyone have new ideas on this? I will try to make a better recording or do some other checks if anyone has ideas.

 

Try to isolate the location of the sound by using a piece of heater hose, hold next to ear and move over engine surface.

 

good idea from Bobf,My wife was reading the thread and her best thought was,wait for it,Turn up the stereo.so it drowns the noise out.Typical!!

 

Here is my view on this, after mine was making this terible noise like a meat grinder and all the information about cam chains etc. I thought lets put the engineering hat on and have look.

First step take the drive belt off when the engine is cold you will need a 15 mm spanner for this and a rag, or perhaps a small steel tube to put pressure on the belt tensioner nut (tensioner located above the A/C pump made of black plastic) it will dig into the palm of you hand if not and the gap between the cooling fans and engine block is to short for a socket and wrench.

Lean on the tensioner nut and pull the belt off all the components (make not of and check this site out for a diagram of how it goes back). Once the belt is off start the engine but do not leave it running, just for enough time to listen for the noise.

Low and behold on my car no noise (good news) after turning the engine off it was case of rotating each accessory by hand to feel which one had an issue.

All the accessories will have bearings installed and if you gently turn them you will feel if a bearing is worn by any notchy feelings, on my car I found the idler pulley (part number NZA2221AA) directly opposite the tensioner was hard to turn and notch. On removing it the bearing was found to be dry thus causing the engine noise. I elected not to buy a new one but flushed out the bearing with WD40 and managed to squeeze some grease in.

After everything put back started the engine and all back to sounding like a sewing machine.

Lessons!! have some faith in the car, if it has been regularly serviced it should not apart from the odd electrical issues have too many major mechanical issues.

Kevo

 

Kevo, I've got an extra 'aftermarket' idler pulley if you want it for shipping cost $10. I thought the idler and tensioner pulley were identical, but turns out it wasn't, so have the extra when I did the change out.

Here's the part number. Dayco 89003 76mm flat, with flange