exhaust fumes through heater?

[Rappey69]

whilst car is moving all ok, stationary and i can smell exhaust fumes if fan is on, not if fan is off? Once moving exhaust smell stops. Exhaust smell is not present in recirculate.
Put car up on ramp, removed plastic undertrays,friend put his hands over tail pipe and not the slightest hint of any leak from exhaust??
where could the exhaust fumes be comming from???

 

[Alex M Grieve]

whilst car is moving all ok, stationary and i can smell exhaust fumes if fan is on, not if fan is off? Once moving exhaust smell stops. Exhaust smell is not present in recirculate.
Put car up on ramp, removed plastic undertrays,friend put his hands over tail pipe and not the slightest hint of any leak from exhaust??
where could the exhaust fumes be comming from???

I guess anywhere along the line of the exhaust system.. Worth setting the car to tick over and blocking the tail pipe with a cloth. Any leaks would become apparent under the back pressure.

If the system is old, suspect the metalwork, if it is new, suspect the connections and gaskets.

It would be good to cure this though as, apart from the smell, you get some carbon monoxide. Whilst it might not kill you directly, it could cause anything from a cracking headache, through to enough driver performance impairment to make the him a hazard to shipping.

 

[Quick Silver]

whilst car is moving all ok, stationary and i can smell exhaust fumes if fan is on, not if fan is off? Once moving exhaust smell stops. Exhaust smell is not present in recirculate.
Put car up on ramp, removed plastic undertrays,friend put his hands over tail pipe and not the slightest hint of any leak from exhaust??
where could the exhaust fumes be comming from???

Is this car a C220 CDI ? If so exhaust fumes may be coming from injector seals . What you have described are classic symptons of this .

 

[Rappey69]

it is a 220 cdi.. I dont think stuffing a rag up the exhaust is possible as my friend had dificulty blocking with his hands due to great pressure..
Hmm, injector seals- will have a look at that in the next day or two...
now and then the car is awefull to cold start too so another reason to check out injectors.
the exhaust looks in very good condition, no surface rust.

 

[television]

That cold start could be the clue to leaky injectors

 

[Quick Silver]

it is a 220 cdi.. I dont think stuffing a rag up the exhaust is possible as my friend had dificulty blocking with his hands due to great pressure..
Hmm, injector seals- will have a look at that in the next day or two...
now and then the car is awefull to cold start too so another reason to check out injectors.
the exhaust looks in very good condition, no surface rust.

Carbon deposits around the injectors will be the give away . Make sure whoever does the job knows what their doing as could be expensive if they don't . Many MB dealers will tell you that you need a new head . Make sure he's a decent mechanic and not a component changer .

 

[Rappey69]

thanks for the replys. Have read much on here regarding injectors.. Can see remnants of a previous attack of "black death" and injectors look clean and shiny so would assume this is not the first time they have caused a problem.

 

[Cole@MBS]

Very common, trouble is, people dont take the time to clean out the bolt hole correctly, then of course the bolt dont tighten to the correct torque!!!

 

[sms78]

i think im guilty of one of these people with dirty bolt holes

 

[Rappey69]

Just looked at the engine and it is an injector leaking.. Many thanks to thoses who contributed as this is something i would probably not have figured out....
now comes the task of the repair (eek)