DPF removal issues.

[LostKiwi]

Revs normally increase and you can get a smell / fumes from under the car

And increased heat and a change in engine note.

 

[malcolm E53 AMG]

Daft question but, How do you know when it's doing a regen?

Can’t comment on the E250Cdi but with my E350cdi the exhaust note increases to a raspy sound and the engine revs increase across gear range by 300rpm and it sits at 800rpm at idle there is also a lot of heat generated beneath the car

 

[Dav1992]

Had another garage to look at the air leak and they can't find anything at all? Could it be a faulty maf sensor? Or would a standard non star computer show a faulty maf sensor?

 

[Craiglxviii]

Had another garage to look at the air leak and they can't find anything at all? Could it be a faulty maf sensor? Or would a standard non star computer show a faulty maf sensor?

Not necessarily reliably…

@V6Matty didn’t you use a chap near Newark, once upon a time?

 

[Dav1992]

Not necessarily reliably…

@V6Matty didn’t you use a chap near Newark, once upon a time?

Oh okay, two different garages checked for air leaks and they couldn't find anything. So I just thought maybe it's a faulty maf sensor. ‍

 

[mioba]

A maf would show up on a scanner, guessing only burns dosh

 

[Dav1992]

These are some of the faults I had when I plugged it in with obd reader.

 

[V6Matty]

Had another garage to look at the air leak and they can't find anything at all? Could it be a faulty maf sensor? Or would a standard non star computer show a faulty maf sensor?

Not necessarily reliably…

@V6Matty didn’t you use a chap near Newark, once upon a time?

Not in Newark itself, I used an Indy in Nottingham, MB Centre out near the racecourse (useful for the park and ride for a day out in Nottingham) or there is also Mercserv on Radford Road in Nottingham, much smaller place but still good guys for diagnosing stuff.

OP have they done a vacuum test or a pressure test to find the leak, you can get different results depending on the test you’re doing

 

[Dav1992]

Not in Newark itself, I used an Indy in Nottingham, MB Centre out near the racecourse (useful for the park and ride for a day out in Nottingham) or there is also Mercserv on Radford Road in Nottingham, much smaller place but still good guys for diagnosing stuff.

OP have they done a vacuum test or a pressure test to find the leak, you can get different results depending on the test you’re doing

Yeah I actually don't know if they did. It was a local foreign garage. I'll try to book in for a proper vacuum and pressure test.

 

[LostKiwi]

Mercland in Nuneaton may also be an option?

 

[Dav1992]

Mercland in Nuneaton may also be an option?

Trouble is every single garage like that won't want to do any work to it just because it hasn't got a DPF but I qt least just want the air leak fixed for now and them eventually I'd just fit a new dpf..

 

[LostKiwi]

That I can't help with. Unfortunately the garage that told you to remove the DPF has sold you down a rabbit hole.

 

[Dav1992]

That I can't help with. Unfortunately the garage that told you to remove the DPF has sold you down a rabbit hole.

Yep, worst case scenario I'll just buy a new dpf the one you found o ebay isn't actually expensive 205 euro which is about 180 quid. And that's new as well, any idea what I'm looking for labour and coding?

 

[LostKiwi]

I'd be going back to the original garage and ripping them a new a***hole personally.

 

[alexanderfoti]

I'd say less than that. Maybe one of the Indies can comment? @alexanderfoti

Roughly that, not sure which car we are talking about. Some cars its a ball ache (w212 V6 Diesel) some its easier. That is about right though.
RHD always have the ****** steering shaft in the way.

 

[tpn]

most of those look like false flags. You cannot have a too high Differential pressure reading in the DPF when you do not have one and you WILL HAVE a too low reading when you do not have a DPF. Incidentally you do not have a backpressure reading/fault, or did I miss it.

A lot of your problem, post removal, would appear to it not been remapped properly.

It would also appear that the Differential pressure sensor was left in place and connected. You need to remove that and loop both tubes together

I am led to believe that a lot of those cheap DPF's are not good, so be careful there.
They are easy to fit on your car, unless your DPF removal garage did not just remove the centre of the DPF leaving the canister in place.

A Snap On diagnostics is good enough to tell the ECU that a new DPF is fitted.

Pre DPF removal:
If there’s a leak in the inlet air, downstream of the MAF sensor, because a hose or seal gets a crack in it , some of that air that the MAF sensor measures is not going into the engine. If that is the scenario the engine is going to be over fuelling under boost and that builds additional carbon etc to stick in your DPF.

Important to eliminate all leaks before fitting a new DPF, Check the differential pressure sensor and DPS tubes for blockages, otherwise you will soon be in a DPF removal loop rather than a measured regen loop.

 

[Dav1992]

most of those look like false flags. You cannot have a too high Differential pressure reading in the DPF when you do not have one and you WILL HAVE a too low reading when you do not have a DPF. Incidentally you do not have a backpressure reading/fault, or did I miss it.

A lot of your problem, post removal, would appear to it not been remapped properly.

It would also appear that the Differential pressure sensor was left in place and connected. You need to remove that and loop both tubes together

I am led to believe that a lot of those cheap DPF's are not good, so be careful there.
They are easy to fit on your car, unless your DPF removal garage did not just remove the centre of the DPF leaving the canister in place.

A Snap On diagnostics is good enough to tell the ECU that a new DPF is fitted.

Pre DPF removal:
If there’s a leak in the inlet air, downstream of the MAF sensor, because a hose or seal gets a crack in it , some of that air that the MAF sensor measures is not going into the engine. If that is the scenario the engine is going to be over fuelling under boost and that builds additional carbon etc to stick in your DPF.

Important to eliminate all leaks before fitting a new DPF, Check the differential pressure sensor and DPS tubes for blockages, otherwise you will soon be in a DPF removal loop rather than a measured regen loop.

Thank you for explaining. I had a guy from Newark a remapping company coking over to do the dpf map and he said he did it but the light keeps coming back on. And he said its a mechanical fault not the map. So not sure if he just talking crap or what.

So if I just wanted to fix the air leak I'd have to remove the differential pressure sensor that was not removed?

 

[bembo449]

this reads like a possible injector fault , think if it were my car id spill test the injectors just to cover the bases

 

[Dav1992]

this reads like a possible injector fault , think if it were my car id spill test the injectors just to cover the bases

****** hell, if one thing wasn't enough

 

[Craiglxviii]

Thank you for explaining. I had a guy from Newark a remapping company coking over to do the dpf map and he said he did it but the light keeps coming back on. And he said its a mechanical fault not the map. So not sure if he just talking crap or what.

So if I just wanted to fix the air leak I'd have to remove the differential pressure sensor that was not removed?

It really sounds like you need to get this car to a reputable MB Indy before you go much further, or you’ll waste money in fixing a problem that doesn’t exist.