EGR flexi-pipe: Exhaust Fumes In Cab, Hissing From Engine Bay.

[DXX]

@Dellmassive

There you go Sir.

Old one against new pipe, and no modifications.
View attachment 45392


This is the one i've just changed after around 24k
View attachment 45393


This is the original one from new, that I changed last year after around 30k
View attachment 45394

I suspect the new one i've just fitted will do around the same mileage. As mentioned above, it's not a big deal because it's a cheap part, and an easy job to swap over.

The first obvious symptom will be the smell of exhaust fumes coming into the cab, and the confirmation is the hissing coming from behind the engine.

On that note, if you or a mod wants to change the title to 'exhaust fumes in cab' or something more suitable for the search box.

Given that this fairly regular failure results in toxic exhaust gases entering the cab isn’t it worthy of a recall / re-design?
I have some experience with much larger engine exhaust system bellows but the principal is the same. The affected pipe is running in two planes (90 bend) but the bellows only allow for effective expansion on the long leg of the pipe. Expansion on the short leg of the pipe will strain the bellows, constant thermal cycling might be causing the cracks.
Some stainless steels ‘work harden’ meaning that the more cyclic stress they are exposed to the less they can handle....until it breaks.

 

[Loz]

Some stainless steels ‘work harden’ meaning that the more cyclic stress they are exposed to the less they can handle....until it breaks.

You would think that the gradual heating and cooling would actually anneal it and keep it soft?

 

[DXX]

You would think that the gradual heating and cooling would actually anneal it and keep it soft?

I just put a magnet on my vans EGR bellows and it’s non magnetic so it’s austenitic stainless steel, maybe 304 or more expensive 316, only VW know.
After a bit of research as I’m definitely not a metallurgist:
316 stainless steel can be softened but needs to be heated to around 1050 - 1120C, way above the exhaust temperature.
480 - 900C should be avoided as at this temperature the steel can become brittle, I haven’t measured the temperature of the pipe which the engine loaded but my guess is that it’s in this range. That said and correct me if Im wrong this pipe is only passing exhaust gas when the the engine is cold??????
I think the main point is that VW don’t seem to have the design fit for purpose and if we kicked off a bit more about exhaust gas in the cab it might just get somewhere.

 

[Tourershine]

Given that this fairly regular failure results in toxic exhaust gases entering the cab isn’t it worthy of a recall / re-design?

My limited experience of manufacturers and recalls, warranty work and the like are not undertaken lightly. The potential costs are millions of pounds, not to mention yet another dent in the VW reputation.

My guess is Volkswagen are aware of this issue, but as per all common problems, they just replace and repair as absolutely necessary, and nothing more.

 

[Loz]

480 - 900C should be avoided as at this temperature the steel can become brittle, I haven’t measured the temperature of the pipe which the engine loaded but my guess is that it’s in this range.

I'm no metallurgist either... but that is the range for regeration.

 

[DXX]

I'm no metallurgist either... but that is the range for regeration.

Doesn’t the regeneration burn take place in the DPF without re-circulation?

 

[DXX]

My limited experience of manufacturers and recalls, warranty work and the like are not undertaken lightly. The potential costs are millions of pounds, not to mention yet another dent in the VW reputation.

My guess is Volkswagen are aware of this issue, but as per all common problems, they just replace and repair as absolutely necessary, and nothing more.

Too true, years ago I worked as an Engineering Modelmaker for a firm in Plymouth that was bidding to produce a heater matrix water valve for a certain German car company. Apparently the small German car named after a popular ball game had a few issues on the top end high performance model......the heater matrix bursting and filling the car with steam. You can guess what happened to the occupants.
Enuf said, I signed a bit of paper..........

 

[Loz]

Doesn’t the regeneration burn take place in the DPF without re-circulation?

I was thinking of the proximity and the close coupling of the rear pipe.

 

[Salty Spuds]

My limited experience of manufacturers and recalls, warranty work and the like are not undertaken lightly. The potential costs are millions of pounds, not to mention yet another dent in the VW reputation.

My guess is Volkswagen are aware of this issue, but as per all common problems, they just replace and repair as absolutely necessary, and nothing more.

I’ve had mine (egr pipe) replaced under warranty. The new one is different to the original. It has more bellows, so they have modified it.

 

[RedUn]

I’ve had mine (egr pipe) replaced under warranty. The new one is different to the original. It has more bellows, so they have modified it.

Pics of that would be really useful if you don't mind

 

[Salty Spuds]

Pics of that would be really useful if you don't mind

It’ll have to be tomorrow

 

[elliot330]

Could be this

Exhaust Fumes In Cab, Hissing From Engine Bay.

Thanks for posting this... it was 100%... using a mirror the mechanic showed me a 20mm slice in the pipe.. booked to be changed when we get back from Holiday.

 

[Salty Spuds]

Pics of that would be really useful if you don't mind

Here you go

 

[DXX]

View attachment 49395 View attachment 49396 View attachment 49397
Here you go

The new bellows look much stronger than the original. They are welded into the tube unlike the old pipe where the tube was formed into the bellows.
Looks pretty similar to the bellows on my 18 year old A4 TDI and thats still going strong.

 

[RedUn]

View attachment 49395 View attachment 49396 View attachment 49397
Here you go

That does look a lot better!

@Tourershine check this out

 

[Tourershine]

Yeah looks like it's been modified.

I obviously tried to be clever by purchasing 2 when my first one went, and ended up with 2 of the older style.

 

[DaveyB]

When you speak of recalls; might be just worthy of note:-
The wife’s Volvo v40 has been listed for egr recall.
My works BMW 3 Series GT has also had an egr recall issued.

Others have the same problem but appear to be more willing to look after their customers perhaps?

 

[Krusty]

Had exactly same issue with my 204, 1st changed at about 27k, going in this week for 2nd 45k. Been smelling fumes for a few days and getting a sore throat when standing in traffic if engine is running. Found best way to avoid fumes is to have air vents set in recirculate and just open the windows every so often when on the move to refresh air in the cab.

 

[Geir-Runar Munkvold]

You have the number of the part?

 

[Dieseldonkey]

Too true, years ago I worked as an Engineering Modelmaker for a firm in Plymouth that was bidding to produce a heater matrix water valve for a certain German car company. Apparently the small German car named after a popular ball game had a few issues on the top end high performance model......the heater matrix bursting and filling the car with steam. You can guess what happened to the occupants.
Enuf said, I signed a bit of paper..........

I had exactly this issue with my 87' MkII GTI. Windscreen started fogging up and my face got decidedly sticky with anti freeze vapour. VW replaced the heater matrix and added a pressure relief valve into the cooling circuit. Car was 10+ years old, yet they did it without charge.

As for this EGR pipe however, I'd be sending an email to VDSA with file attached photos of the failed pipe. I'd also include a link to this thread so they can see it's not an isolated issue. I'm sure VDSA have the power to force a manufacturer to perform a recall, given the seriousness of the consequences where exhaust gas leaks into the cab.