VW 1.9 tdi engine (110 bhp - PD I think)

[SplendiferousII]

Not T25 related but.

I have a seat Toledo (51 plate) with a 1.9 tdi engine fitted. Its been a proper pain in the a*** but for the past year its behaved itself.

This evening however after parking it for a few mins, I restarted it and it knocked and didn't fire up. I tried again and all was well.

I drove home and tried again. ok . I switched it on and off a few times and once it made the nasty knocking noise.

It sounds like a piston hitting a valve but it has had new hydraulic tappets fitted a year or so ago because the valves would stick open and you would lose compression.

Do the bottom pulleys slip on these engines? - but then why would it only do it occasionally? and it drives just fine.

[busbuddy]

what do you mean by knocking?

big end style knocking or engine going to rip itself out of car knocking

[SplendiferousII]

Piston and valve coming together sort of noise. Quite mechanical. Although I really cannot believe it is as its going very well still. I have tried starting and stopping it again a number of times and nothing now. Baffled.

[HarryMann]

Probably diesel knock.. detonation.
Is oil leaking into the turbo or building ip overnight (blue smoke)
Too much fuel ( grey smoke)
Use any water?

Have you checked/ changed both fuel & air filters?
Is cold start mechanism working right? Staying on too long. Has it any plugin disgnostics ?
Run some injector cleaner through it maybe... ill get you the name of good stuff ibfound on a stall at CamperJam.. magic fuel additive for diesels.