Diesel fumes getting into cabin

[911hillclimber]

2014 Superb Estate, 80K miles, bought new by me, lovely car, 2 litre turbo Diesel

However..

Recently, while standing still, engine running at tick over fumes will enter the cabin space very quickly from start-up.

Cabin filter is the top level of filtration, does this with all windows closed, fan on '2 marks' A/C off.

No blowing or unusual noised from engine bay anywhere esp around the turbo.

Performance is strong as ever, tows well etc.

Any experiences/ideas/solutions please?

[DEL80Y]

Get the flexi section in exhaust checked for cracks  

Or a loose clamp 

Its basically positioned right underneath the front windscreen scuttle so any exhaust fumes escaping come right into the air intake of vehicle

Edited 14 December, 2022 by DEL80Y

[911hillclimber]

Thanks for your reply. I had this problem 3 years ago, the turbo/manifold gasket was changed and the special clamp too, and the AUDI specialist who did the job checked things over, but I was never convinced it was right. The car is a 4x4 Tour de France which cramps the space in and around the turbo so hard to check, but will follow it all up.

Will try another garage, the AUDI guy can't be trusted.

The turbo is all sealed as an engine bay by a thick rubber seal so I would hope any fumes would be kept away from the air intake and the filter would catch any fumes that might get by.

If leaking, a soot should be present?

Edited 14 December, 2022 by 911hillclimber

[landroverbodger]

mine was letting fumes into the car when standing. it was trying to do a DPF regen gave it a good run and it cleared it.  

[911hillclimber]

Thank you for that, I'll give it an Italian Service asap!

[fabia88]

I had the same issue too, turned out the mechanic that changed the egr valve before my ownership snapped a stud in the exhaust manifold and stripped a thread in the egr causing an exhaust leak.

[911hillclimber]

Thank you for your reply.

I've have this car from new, and know nothing has been done like that on this engine, but the last 'specialist' did change the steel manifold/turbo gasket and clamp using VAG parts.

I think this repair has failed again. hope to check around the area tomorrow now the freeze is over for a few days. You can stretch over the engine when just started and while things a cool and the mixture rich.

[Iperboreano]

Interesting discussion, started getting the same fumes into cabin issue about a month ago on a 2010 Octavia Scout TDi that's done 80k.  I suspected an exhaust leak in/near the engine bay, and for now have managed by turning on cabin air recirculation every time I drop below third gear; it works but it's tedious.

Some months prior to the fumes, I noticed the engine had started doing a slight wheezing noise, like air being sucked through teeth, but no fumes.  At the same time mpg dropped by 10-20% from what it used to be.  Local garage spotted a fine crack in the turbo housing causing loss of air, which would explain the wheezing, loss of efficiency and no fumes problem, said it would be expensive to fix so have left it for now (don't do many miles).

Local garage couldn't find fault causing recent fumes though, so yesterday had the car checked over by a DPF specialist.  They reckon it's not a DPF issue, but the EGR valve leaking fumes, which then get sucked into the cabin when stationary or slow.  Thanks to the Scout's rear drive transmission box, the EGR valve is inaccessible and it's going to be potentially £600 to fix.

Sound plausible?

It doesn't sound like something which an EGR cleaning spray is going to fix!

[Fekker]

I had a problem with diesel fumes, turned out to be one of the injectors was leaking, once the engine cover was removed I could see diesel around the top of the injectors.

[911hillclimber]

Thank you all for your replies, all helpful.

I've been putting my head in the sand over this as while driving the burnt fumes do not invade, and when hot the stop/start stops fumes too.

However, I did a quick cold start examination around the turbo area:

Cold engine allows hand access to the area between the turbo itself and the bulkhead. 

There is a noticeable cold  area that suggests a fine leak and air/fumes escaping under pressure.

This 'draft' is coming from the bulkhead and not from the turbo/engine (!)

 

What could be mounted around that area?

 

Since new there has always been a light 'wheeze' sound from the turbo changing from 1st to 2nd, no other gears.

The fuel consumption can be a carefully driven 60 mpg (4x4 remember) or a more normal/town driving of 46/49mpg.

Towing the trailer and car = 32 mpg.

 

The car is starting to get expensive (81K miles) and I wont spend hundreds on this issue but may be time to p/x and get something else, maybe another petrol engined 4x4 Superb.

[fabia88]

If you think the exhaust is blowing from there, I believe the main possibilities are:

1.exhaust manifold gasket 

2.turbo to dpf gasket 

3. Gasket for pipe that goes to the egr valve from the manifold

 

 

 

[911hillclimber]

And all murder to get to I guess esp as the car is a 4x4 version.

Will have a think how to move forward.

It's had a new steel 'shim' gasket and clamp from manifold to turbo about 3 years ago when this rose it's head.

Did nothing.

[fabia88]

I have a possible idea, buy a cheap smoke machine, connect it to the end of the exhaust sealing it with duct tape and see where the smoke leaks out, this eliminates the guess work. I believe this method is also used to detect intake leaks too.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[911hillclimber]

I'm ahead of you!

When all this game started someone on here suggested fine Baby powder(!).

I hired a ramp locally (£8 hour, a bargain) got the car up and 'puffed' baby powder in the turbo area while the engine was hot and running. I dowsed the length of the exhaust too.

The baby powder is very fine and whaffs about in the air. Any leaks and jets of gasses would show as disturbance of the powder as you suggest.

Absolutely nothing, the powder just sank slowly through the air to the ramp.

 

I did this for about 30 mins all to no avail.

 

I did tell the operator what i was doing as he was very surprised, but said the workshop had never smelt so nice!