Chufffing injector

[BlackC55]

Just had a car in with a loud chuffing noise from under the bonnet. Under further inspection I found one or two injectors to be leaking combustion gasses.

I have never seen this on aa A-class. You normally see it on the 220, 270, 320 CDI's

I just thought you would like to see a pic of it because it is an unusual fault on an A-Class diesel.

 

[fredfloggle]

Did it look like the injectors had been drawn at some point ? or was there a possibility that it had got a bit hot ?

 

[timskemp]

Not unusual at all - search http://www.baby-benz.co.uk for more info - mine did it, as did many others.

Reality is that not many As go to high miles so they don't see it that often.

Removing the injectors is a huge pain too.

 

[jaymanek]

I have this on almost every ML diesel i sell! and its worse on low mileage cars... sometimes new seals cure it, more often than not its new injectors..

 

[BlackC55]

Finished it today. Was a bit awkward but generally ok.

The culprit was a completely broken up copper seal. Normally they stay intact but this one was in bits. It was not much fun digging the bits out.

 

[jaymanek]

yes my mechanic moans about that too!

 

[Dieselman]

Jay
Why do they normally require injectors, are they burning away due to the hot gas escaping?
I would have thought new seals and sealant would have fixed most of them.

 

[jaymanek]

Well sometimes the escaping gasses and diesel builds up so much carbon around the injector that even after breaking it all up, the injector will not move and has to be forced out with mole grips (and a lot of sweat and patience)... and forcing usually means breaking the top part!

I cant believe that the injectors are just push in pull out, in my opinion they should have some sort of thread to be able to coax them out easier.

id say around 50% of the cases we get away with just the seals..

the cheapest i have found these injectors for is around £130 each + vat

 

[Dieselman]

I cant believe that the injectors are just push in pull out, in my opinion they should have some sort of thread to be able to coax them out easier.

It's because the fuel connections have to line up with the HP pipes and the injector has to fit a certain way round for spray pattern.

The clamps are not sufficient.

 

[BlackC55]

Well sometimes the escaping gasses and diesel builds up so much carbon around the injector that even after breaking it all up, the injector will not move and has to be forced out with mole grips (and a lot of sweat and patience)... and forcing usually means breaking the top part!

I cant believe that the injectors are just push in pull out, in my opinion they should have some sort of thread to be able to coax them out easier.

id say around 50% of the cases we get away with just the seals..

the cheapest i have found these injectors for is around £130 each + vat

Tell me about it!!!!!

 

[jaymanek]

its not fun, my mechanics have said they dont want to see another CDI engine ever again... that may be a little difficult me thinks..

 

[Dieselman]

Have they tried Coke or vinegar before trying to remove the injector. Also are they trying to pull the injectors out or to use a slide hammer.
The hammer should work where the pulling fails, but you need to be careful not to snap the top thread off the injector, mind you they're scrapping them anyway so no loss.

 

[jaymanek]

well no as the point is to remove the injector without damage as all you want to do is replace the seal!

 

[Dieselman]

I realise that. What I meant was at the moment 50% of the injectors are being scrapped so no loss if the puller damages the odd one.