Unbearable Diesel fumes - A170CDi

[Rez]

Folks,

Ever since we got this car we've had problems with diesel exhaust fumes getting in the car and the problem has recently got worse, to the point that I get pounding headaches and I physically want to be sick after short drives. This is clearly doing me no good and I hate to think what it's doing to my 14 month old daughter, to the point that I try to avoid taking her anywhere in it if at all possible.

At a recent service I mentioned this and they've replaced the exhaust gaskets in case they were leaking but to no avail. I reported this back and they suggested an exhaust place check out the system for leaks. I did this today and Kwik Fit were able to show me that none of the exhaust system joints had a leak.

Is this a common fault? I need to get this fixed ASAP and could really do with some pointers.

Thanks in advance.

Rez

 

[television]

Hi Res,we had the same question last week by someone else, hard to know whats causing it. We ended up by thinking that it must be the rear door as fumes can be pulled in like when you have the rear door on a estate car open.

See if any one else has an answer in the morning.

I have searched all of the MB technical papers and nothing there

 

[Rez]

Thanks for the response Malcolm.

I really hope someone can point me to a solution or I'm going to have to get rid of the car.

Cheers!

Rez

 

[JEZ.S320L]

Thanks for the response Malcolm.

I really hope someone can point me to a solution or I'm going to have to get rid of the car.

Cheers!

Rez

Not good - especially when Little People are at risk.

Have you tried the 'paper test' on the rear door seal? i.e. open door - put paper between door and seal - close door - try and pull paper out? If you can pull it out easily - there's your answer, new rear door seal required.

Good Luck.

 

[BlackC55]

The injectors may be leaking at the base allowing combustion gasses into the engine bay and then into the cabin. Have done two recently.

 

[Rez]

Thanks for the replies guys, Much appreciated!

Will defo try the paper test on all the doors and the tailgate.

Re the leaking injectors, are there any signs to look for... in fact, where the hell are the injectors... I just can't get my head around this funny little engine!

Rez

 

[BlackC55]

Thanks for the replies guys, Much appreciated!

Will defo try the paper test on all the doors and the tailgate.

Re the leaking injectors, are there any signs to look for... in fact, where the hell are the injectors... I just can't get my head around this funny little engine!

Rez

The big plastic inlet manifold on the top. They are under there. Buried deep.

You won't be able to see them either. Normally the smell goes with a chuffing noise.

 

[Rez]

Right then... did the paper test... at least I hope I did it right!

Took a fresh sheet of A4 and put it into the front door... pretty tight and a good tug to get the sheet out.

Rear doors not so much of a struggle and neither was the tailgate.

Perhaps the door seals are the culprits!

Any ideas how much a set of rear door seals and a tailgate seal are likely to cost?

Plus, I have a choice here in Derby of where to go to get them, the Merc dealership and the ex Merc dealership, Mertrux. Any suggestions?

Ran the engine with the bonnet up and there could be a small chuffing noise but to be honest being new to diesels this could be anything! Noisy beggars aren't they?

Also, are there any air vents in the bodywork that might have flaps to prevent such ingestion that might be stuck open? I know most cars have a vent of some kind to allow air to get out of the car...

Thanks again for your help!

Rez

 

[mattkh]

Ever since we got this car we've had problems with diesel exhaust fumes getting in the car and the problem has recently got worseRez

Hi
What was the miles to the gallon when you bought it.
Is it the same'ish now? If not, then the injector leaks could be the culprit.

 

[JEZ.S320L]

Right then... did the paper test... at least I hope I did it right!

Took a fresh sheet of A4 and put it into the front door... pretty tight and a good tug to get the sheet out.

Rear doors not so much of a struggle and neither was the tailgate.

Perhaps the door seals are the culprits!

Any ideas how much a set of rear door seals and a tailgate seal are likely to cost?

Plus, I have a choice here in Derby of where to go to get them, the Merc dealership and the ex Merc dealership, Mertrux. Any suggestions?

Ran the engine with the bonnet up and there could be a small chuffing noise but to be honest being new to diesels this could be anything! Noisy beggars aren't they?

Also, are there any air vents in the bodywork that might have flaps to prevent such ingestion that might be stuck open? I know most cars have a vent of some kind to allow air to get out of the car...

Thanks again for your help!

Rez

Glad to have been of help - it's the Little One that worried me. I would seriously consider replacing the loose door seals ASAP. Try your local MB garage, you may be surprised . Little One's health is FAR more important than cost.

 

[Rez]

UPDATE:

A mate and I did a little investigating this weekend to see if we could identify when and where the smell was coming from. All the seats bar the drivers seat were removed and my mate was driving around in a variety of conditions whilst I moved around the now surprisingly spacious A-Class sniffing at door seals, vents etc.

We think we've narrowed the problem down to when the vehicle is moving slowly, such as in stop start traffic. Under these conditions the smell gets very strong, suggesting the gas is coming from under the bonnet and through the fresh air intake at the base of the windscreen. Any faster and the smell seems to go away.

We've had a look under the bonnet to see where we think the smell is coming from and it seems worst at the N/S end of the plastic inlet manifold thing with the metal device hanging down.

As mentioned before there is a small but distinct sound coming from the engine... either a rythmic tick tick tick or the sharp sound of gas escaping.

I'm guessing the injector leak may now be the issue. You've mentioned it's buried deep... but is it accessible or it is it a dealer option? I've got Torx head tools so I may just start removing the plastic bits and see what I can see!

If it is an injector leak... is it as simple as just tightening it or is that a new injector required?

Thanks again for all your helps folks!

Rez

 

[JEZ.S320L]

UPDATE:

A mate and I did a little investigating this weekend to see if we could identify when and where the smell was coming from. All the seats bar the drivers seat were removed and my mate was driving around in a variety of conditions whilst I moved around the now surprisingly spacious A-Class sniffing at door seals, vents etc.

We think we've narrowed the problem down to when the vehicle is moving slowly, such as in stop start traffic. Under these conditions the smell gets very strong, suggesting the gas is coming from under the bonnet and through the fresh air intake at the base of the windscreen. Any faster and the smell seems to go away.

We've had a look under the bonnet to see where we think the smell is coming from and it seems worst at the N/S end of the plastic inlet manifold thing with the metal device hanging down.

As mentioned before there is a small but distinct sound coming from the engine... either a rythmic tick tick tick or the sharp sound of gas escaping.

I'm guessing the injector leak may now be the issue. You've mentioned it's buried deep... but is it accessible or it is it a dealer option? I've got Torx head tools so I may just start removing the plastic bits and see what I can see!

If it is an injector leak... is it as simple as just tightening it or is that a new injector required?

Thanks again for all your helps folks!

Rez

Glad you are starting to track it down - PLEASE reassure us on the forum, that you will NOT put your Little One in the MB, until it is sorted out.

Thanks

 

[Rez]

Never fear Jez... the car seat has been moved into our 5 series BMW for now so we're good till we get it fixed.

Cheers

Rez

 

[JEZ.S320L]

Never fear Jez... the car seat has been moved into our 5 series BMW for now so we're good till we get it fixed.

Cheers

Rez

Good! We can sleep a little easier now

 

[BlackC55]

Removing the injectors and re-sealing them is probably going to be the answer.

The injectors can be VERY difficult to remove. Beware. I have a tool to remove them but it renders the injector U/S.

The A-class CDI injectors are more difficult to remove than most due to the access.

See: http://www.mbclub.co.uk/forums/showthread.php?t=39534

I have done one that needed the injector seat re-cut. Around £350.

If you need any more help just ask.