Technical pinking diesel

[Les Holloway]

Hi, I have a problem with what appears to be pinking with my 2003 JTD.
if you are perhaps in slightly too high a gear then when you accelerate you get a pinking sound which then disappears after a short time.
I have cleaned the EGR valve, put through an injector cleaner and there has been some improvement but it can still be there.
Any ideas

 

[momoe]

what sort of use does the car get?

 

[Les Holloway]

Every day, long and short trips

 

[pete123]

It sounds like u have a air leak in ur vac pipes if upstart car and rub around the pipes u should feel air sucking in if there is a leak

 

[Les Holloway]

Sorry to be so dim what are the vac pipes and where are they?

 

[pete123]

That I can't help with as far as I no they are under the manifold somewhere I had mine cleaned and done at same time as my head gasket by a fiat dealer

 

[momoe]

AFAIK, the vacuum pipes connect the vacuum pump to the brake servo, can't see why having a leak would cause pinking, might cause the brakes to need a stronger right leg.

I asked about the usage as I wondered if there was a carbon build-up which was causing pre-ignition but this sounds unlikely given the usage.
Have you checked the auxilliary belt pulleys? These have a rubber flange separating the two pulley halves, if the rubber is shot the two halves can move which makes a tinny (sort of) noise.

Can't think what would cause pre-ignition as there is a cam sensor and a crank sensor which ensure timing is accurate, if one of these on the way out you'll get an engine fault (Timing mismatch).