406oc.co.uk

My hdi has a light knocking/tapping noise that is heard up to 3300 rpm then disappears.It sounds like its coming from the right hand side of the engine as you sit in the car.Has anyone had this and if so is it normal?

Interesting read. (TBH it's the first time I've read the KB article from 'cover to cover').

From my recent (2.2) injector swapping experience, I can add a couple of observatons:
1). A DIY leak-back test rig is easy/cheap to knock up - I only had to buy 5m of 3mm w/washer pipe. Took 30 mins to make & about the same for the test.

2). The official word is that injectors of different classes can be used, but it is recommended that all 4 are the same.
3). Regarding re-coding the injectors to ecu, PP2000 instructions imply it is unnecessary when changing a single injector, but recommended when changing 2 or more. It's simply a matter of 'instructing' the engine ecu to re-calibrate the trim percentages over the next 50 'journeys'

HDi's don't use knock sensors, the camshaft sensor is used to measure the acceleration generated by each cylinder firing. This data is used to generate trim percentages for cyls 2-4, which are used to adjust the injection volume on each cylinder, until they balance. If you know what you're doing, analysing these values can help diagnose issues of this kind.

Doggy, do you think that your wobbling problem is somehow related to the famous one Steve linked too?
I've never heard of the noise-before-3200 problem on 2.2s, so it probably touches only 2.0s?
I've never noticed it in my car, but I've had it for little more than 1000 miles up to now. I don't have it at hand and I won't be able to check before tomorrow evening, argh!

Damn you guys you always make me run to the car to see if it has the same problem every time

Yes, I believe both issues are symptoms of worn injector(s). Having owned both 2.0 & 2.2's, I agree the 'tapping' or pinking noise only seems to affect 2.0's for some reason, (but this could be just the different cyl head / manifold construction changing the way it 'sounds').

Odin, - if it ain't broke, don't fix it!

dogslife wrote:Yes, I believe both issues are symptoms of worn injector(s). Having owned both 2.0 & 2.2's, I agree the 'tapping' or pinking noise only seems to affect 2.0's for some reason, (but this could be just the different cyl head / manifold construction changing the way it 'sounds').

Odin, - if it ain't broke, don't fix it!

Thanks mate, I agree! By the way I do not care much about noise... And loss in performance / fuel consumption should be minimal