Thread: Tdi pinging

Hi Wally,

I've got the same thing with my 300 tdi. Almost sounds like body panels squeaking as they rub together. I've managed to get under the cab while at idle to try to pin point the noise while it's still there but can't find exactly where it's coming from. Doing my head in! Interested to know what this is also.

OK. It's been suggested to me that it's a little bit of "diesel knock" and that optimising the injection timing will probably have it sorted. I know it's usually impossible to diagnose a sound without hearing it, but does that explanation sound plausible?

If the injection timing on my Diesel 2A was too far advanced it did sound tinny, even like a tin of ball bearings if it was really advanced. Setting up the timing with a magnifying glass to get the timing marks in line solved this. Then I left it alone.

Originally Posted by wally

OK. It's been suggested to me that it's a little bit of "diesel knock" and that optimising the injection timing will probably have it sorted. I know it's usually impossible to diagnose a sound without hearing it, but does that explanation sound plausible?

Have you tried removing the fan belt and aircon belt and check if the noise is still there, Regards Frank.

Thanks for the suggestion there Frank but I'm quite sure it's not coming from the belts. When I can find the time I'll get the injection timing checked and I'll report back. Finding the time is the hard part.

Originally Posted by wally

Thanks for the suggestion there Frank but I'm quite sure it's not coming from the belts. When I can find the time I'll get the injection timing checked and I'll report back. Finding the time is the hard part.

Only takes a minute to remove belts and if there is no change then you have eliminated the pulleys and pumps from the equation, Regards Frank.

With a TD5 I'd start to think about the Harmonic Balancer.

Mentioned it in here a few times. Small background tapping. However I would not have called it the same or similar to "pinging" "detonation" in a SI engine. Definitely a light background tapping behind the diesel knock/rattle.

Almost had the engine pulled to bits looking for it, many $. Never really identified. Around 30 000km later the balancer failed catastrophically. New balancer and the sound had disappeared.

Cheers

RF

list for such noises on a 300 include but not limited to,

Air filter can mount rubbers, they perish can rocks and rolls and can tink against the head
Injectors at end of life
Tappets
Timing

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