Knocking Injector

[kwakdonut]

Get some Forte Engine Flush - I have heard that this is very good for quietening noisy tappets. Good excuse for an oil change too!

 

[Smiley]

How old and how many miles does the car have on it? My 124 300d has been knocking away at idle for more 10s of thousands of miles than I care to remember but still runs fine on the move and the fuel consumption is still the same so I have just left it.
Unless you have other problems it may be better just to leave it and save the ££££ that this will cost.
ps I replaced all the injectors in mine about 50k ago - it was distinctly noisier immediately after the change but quietened down gradually over the next 10k miles. No idea why.

 

[Olivier]

Hi ya, the tappets are hydraulic so the only option is to change the offending one, they are not big money but the expence comes from having to pull all the injectors and remove the rocker box which if you have had a leaking injector can be a pig of a job. i have one that is occasionaly noisey but i can live with it. Have you done an oil change lately?? this can sometimes cure a noisey tappet

Cheers Martin

Why would it be a pig of a job with a leaking injector? Because of diesel?
How do you spot a bad tappet?
Cheers.
Olivier

 

[Danny DeVito]

Why would it be a pig of a job with a leaking injector? Because of diesel?
How do you spot a bad tappet?
Cheers.
Olivier

I think probably my car would be a good example of what happens. Under the cover the entire engine top was caked in black carbon. I could not see the injector pipes or the wires right up to the return pipes it was. I had to chip it all away and of course the stuff had nearly welded the faulty injector in. So the expense is in the time it takes for you(cheap labour) or the garage(rob you blind) to remove the injector. The injectors having to be taken out to remove the rocker cover to access the tappets. Sorry i don't know though how to spot which tappet though. I can tell you that on my car once everything has been loosened up it only takes about half an hour to strip it to the rockers.

 

[Wee T]

Knock

The latest diagnossis is a bent conrod due to a faulty injector injecting in too much fuel and causing cylinder No 2 to suffer from hydraulic lock.Apparantly this would normally happen during start up and is in my case unusual as it happened whilst driving along at 50 mph towing an empty car transporter.
The car is with a proper local specialist to have the head removed to see whats happening.Cylinder No2 is well down on compression.Unfortunately they are closed for a week so i'll not know for sure if thats the problem until they re open.I'm not looking forward to the bill.

 

[Wee T]

Knock

It has only covered 85k miles and has full Dealer service history.

How old and how many miles does the car have on it? My 124 300d has been knocking away at idle for more 10s of thousands of miles than I care to remember but still runs fine on the move and the fuel consumption is still the same so I have just left it.
Unless you have other problems it may be better just to leave it and save the ££££ that this will cost.
ps I replaced all the injectors in mine about 50k ago - it was distinctly noisier immediately after the change but quietened down gradually over the next 10k miles. No idea why.

 

[Laurencet]

Any Closer?

I'm having a similar problem with a c270 cdi, Seems to be knocking loudly all the way through the rev range, well down on power, Can't imagine it's the tappets on mine though just had all the injectors tested, Which appear fine. also tested the compression which was 23bar across all cylinders (cold Engine)
Hopefully plugging the car into a computer on Monday and see if it gives me any clues, the diesel specialist who carried out the injector testing suggested the egr valve was choked up... Might be worth cleaning this weekend..
If you get any closer with yours let me Know...

 

[Ted]

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