recurring carbon build up EGR? Saab 2.2 TiD

[aston]

Hi all, Basically our 2.2 Tid Saab (GM Vauxhall) Diesel has been smoking a lot and returning bad MPG (Running Rich), So I visited my mechanic who cleaned the map sensor, (Cured briefly) shortly afterwards the car was bad again, I cleaned the sensor, again good for a while then bad, So I cleaned the Manifold, full of oily, tar carbon. again shortly afterwards the car was bad again so back to the mechanic, he removed the mainfold, EGR Valve and map sensor and cleaned the lot 100% nice and shiny like new, again it was all filthy and running rich (due to fouled map sensor). The thing is there are no fault codes coming up as if the EGR Valve is working correctly, but my mechanic thinks the only way the carbon can get there is through the EGR Valve so maybe it is sticking open for too long. He is only guessing and I don't want to fork out ££££££££'s on an expensive part if this is not the problem.
Any ideas folks, cheers

[HDi fun]

Blanking off the EGR and getting it mapped out in the ECU will should help greatly. However, it is possible that the turbocharger seals are allowing a fine oil mist into the air intake tract. This is not uncommon but as the seals wear this mist becomes more significant. I'm pretty certain that the turbo can be overhauled in most cases.

[jarrus]

Blanking the egr is the best solution here, you might not even need to map it out as the 2.2 is and old generation diesel.

[waynne]

Are you doing lots of short journeys?

[aston]

its the car my wife drives. I guess she does medium journeys, 7 miles there and then 7 back. My mechanic thinks it's the egr valve but I am not convinced, no dash lights, no codes, it works remotely. I was wandering if diesels have chokes? Possibly a temp sensor is not working fooling the ecu into thinking the engine is cold and therefore keeping the egr valve open too long and running too rich.
The egr can't be blanked with this car unfortunately .
Now the MPG is awful for a diesel, average 36/37mpg, should be 42/43 in this car

[jarrus]

Trust me, it can be blanked..... It can be blanked in any car with the correct know how...

[HDi fun]

Diesels don't have cold start enrichment. Nor do they have throttles. Does it smoke in normal driving?

The MPG you report is perfectly acceptable for 7 mile trips - these are short journeys.

Try the Turin approach.

[PedroS]

if all the hardware is good , why not a remap ? with this solution you can get around the egr working cycle ... anyway i am with HDI fun... get the turbo checked....

[aston]

I am now cleaning the map sensor on a regular basis. A cheap fix but works, It seems the saab diesels are CARBAGE

[jarrus]

You shouldn't have to, a mate of mind has a vectra with the same engine in, his has done 133,000 miles and he doesn't have to do this...

[aston]

Right, I have took it to a different mechanic and things seem to be looking up, This guy tests components rather than changes everything until it's working, He says it has a very good engine, the fault is EGR related......I'll know everything tomorrow

[aston]

still none the wiser, someone must have had the same problem

[Jakeymd]

There must be a way of blanking it off somehow.

[aston]

I am wondering if the problem is a dirty/blocked air-filter, But hey I went to have a look and Saab in all it's wisdom have designed the air filter so to change it, it seems one has to remove the front wheel, Inner wing and also be in a garage pit....GGGGGGGGGGGGRRRRRRRRRRRRRRRRRRR

[aston]

Seems it's not the air filter.............AAARRRGGGGGGHHHHHHHHHHHHHHHHHHH HH

[jarrus]

Pull the vaccumm hose off the EGR, will be worth doing even if the EGR isn't at fault,

The next port of call like everyone says is the turbo.

[aston]

Fixed at last, the problem was a ruptured diaphragm which operated the swirl valve in the swirl chamber...... Now the car is normal, a piece which cost £5 from the local breakers and took just two minutes to swap.............Brilliant

[Jakeymd]

Glad it's all sorted buddy

[aston]

Yes. Not too happy with the mechanic who kepmy car for 6 weeks over Christmas/new year. At least I can sell it as a good car now. Just 2 more cars to fix

[HDi fun]

And another ten to buy

[T9 man]

Originally Posted by aston

Fixed at last, the problem was a ruptured diaphragm which operated the swirl valve in the swirl chamber...... Now the car is normal, a piece which cost £5 from the local breakers and took just two minutes to swap.............Brilliant

Really happy for you buddy