c220 cdi 2003, tapping noise and smells from heaters

[mitch1981]

hi, i just wondered if anyone can help, my 2003 c220 cdi has just started to make a tapping noise from the engine when running, wheb i put the heaters on i got a strong smell coming through, it is a kind of burning smell, i topped it up with oil as it needed 1 litre, the car has done 90,000
Has anyone got any ideas, thanks

 

[momomo]

That tapping sound you mention could be an injector and is the smell like diesel or actual burning oil? Your injector seals may need replacing. Have you had a look at your injectors?

 

[mitch1981]

1 injector did get replaced 2 years ago which cost 300 with diagnosis, is it best to replace all when 1 go's which is what the garage said but it was the cost which meant i couldn't replace them at the time, the smell is like burning oil

 

[momomo]

No, you dont really have to replace all of them if one is replaced, unless there is something wrong with them you should leave them. If anything most of the time getting the injectors refurbished by diesel specialists or certain bosch agents is better, as the cost of replacing all of them with new ones is way too much.

You said it was low on oil and needed topping up and you're smelling oil burning. Have you had a look around the engine to see if there are any oil leaks? Best place to start.

 

[mykulmerc]

The tapping noise could just mean one injector seal has failed - it might not even be the injector. If this is the case there will be a build up of carbon around the injector. Theseal only costs about £1 but it is a pig of a job, or at least can be. Last one I thinik cost me £125.

This can also lead to a smell of fumes inside the car.

 

[mitch1981]

thanks for your replies, the noise its making is a tapping and hissing noise, due to my long hours at work i haven't even had chance to take the engine cover off to look at the injectors, but the noise is coming from around where i guess the last injector is, there is no power loss, i will make time tomorrow to check the injectors, thanks for your help, any more ideas

 

[momomo]

The hissing sound will quite certainly mean it is the injector seals. Yes have a look at the injectors when you can. I asked you to have a look in my previous post as they get carbon build up around them which means the seals are gone but the hissing sound also gives it away.

 

[mitch1981]

you said the last one cost you £125, did you mean for the seal and labour or for the injector and labour, because like i said above i paid £300+ for the injector and diagnosis, i just wondered if i'd been ripped

 

[momomo]

Bluec220 is saying the last time he had an injector seal replaced thats how much it cost.

 

[mitch1981]

ah yes, sorry, i will have a look at them tomorrow, hopefully its just 1 seal leaking, does this explain the smell from the vents inside

 

[momomo]

Yes as the seal is no longer sealing the seat of the injector, the fumes are escaping and entering the cabin through the vents.

 

[nadeem]

My dad had the same problem with injector no 3, changed the seals 3 times in the last couple of years. Injector on ours a right pain to take off. It's now due for another as we can smell the fumes in the cabin, saying that the seal near the turbo needs replacing clearly see exhaust escaping when cold starting.

 

[mitch1981]

thanks for the help, i have also read some old posts aswell

 

[momomo]

My dad had the same problem with injector no 3, changed the seals 3 times in the last couple of years. Injector on ours a right pain to take off. It's now due for another as we can smell the fumes in the cabin, saying that the seal near the turbo needs replacing clearly see exhaust escaping when cold starting.

Nadeem that seal should not be going that many times within a couple of years.

Who is is replacing the seal? The reason it keeps needing replacing is because whoever is doing the job is not doing it correctly.

The injector seat needs to be recut with a special tool before a new seal should be used. This will ensure it wont happen again.

 

[nadeem]

Initially we replaced all the seals as injectors 1 and 3 were leaking, as per recommendations by Mercedes in Chester. Injector 3 seems to go every 9 months... We further tightened the bolt by 45 degrees holding it down and so far so good.