Urgent Help Needed the car is at the garage for MOT

[poleposition]

Happy new year guys, please advise on the following,

The car is now at the dealer, with the following serious issues:

1. Huge Fuel Consumption (avg 50 liters / 100 KM) - 4.7 MPG

2. Extremely high emissions on the exhaust, like 10 times more than normal, plus smoke. White/bluish smoke.

They are not sure what it is, the car has been there for 2 weeks, please give me something to tell them at least... they are so incompetent, it is unbelievable.

I was supposed to renew the MOT, but with these emissions, there is NO WAY !

What could it be ?

So far, the coils and sparks turned out OK, whatever else they verified they said it checked ok... still the smoke, high emissions and 4.7 MPG.

Edited January 4, 2011 by poleposition

[david_yorkshire]

lambda sensors ?

is it throwing any error codes or CEL ?

[poleposition]

The CEL was on, but due to a bad wire on a coil, so now it is off, still the problem remains.

If there were the lambdas, the CEL would light up right ?

I don't understand how it can be off, with all that smoke !

[mudman2]

That does not sound good, head gasket, headers damaged, it would help if you could list the codes

[Loren]

... and check the coolant level.

[wvicary]

Whats the repair history on the vehicle? Was it operating correctly before the MOT inspection? Also inspect the oil for fuel contamination.

[poleposition]

The car was serviced only at Porsche Dealer, no major repairs, before this MOT, everything was fine.. well, i've noticed a bit of smoke when the engine was cold, but that was it.

Head-gasket is ok, coolant level ok.

They mentioned a few hours ago the lambda probes, but this morning they said they were ok. Sorry, it is 9PM here :)

So they can't give me an answer for the 4.7 MPG fuel consumption... or could this be from the lambdas ?

I hope they will give me some error codes for me to post.

Thanks.

Edited January 4, 2011 by poleposition

[mudman2]

I wonder if they fried the DME

[wvicary]

If it developed a misfire due to a faulty coil pack and it has now been replaced, clear all codes and road test the vehicle to complete at least one drive cycle. You might be trying to repair a problem that doesn't exist due to the fact that the DME is still adapting from the misfire fault.

[poleposition]

update

Edited January 6, 2011 by poleposition

[poleposition]

UPDATE:

Just got a call from the garage:

They told me the emissions are now perfect, what they've done was, and i quote "a reset/self cleaning procedure on the lambda probes", and all is fine now. And of course the car passed the MOT.

Do you have any idea what that means ?

Edited January 6, 2011 by poleposition

[wvicary]

I would guess they just drove the vehicle to recalibrate the DME and purge the cat convetors, just what I would have done.

[poleposition]

Maybe they did so... Anyways, I will pick it up Monday, and see for myself.