2006 1.9 tdi BLT PD130 completely stock

Egr vac line disconnected car runs perfectly, nothing to report. Engine light is on. Been running like this for 8k miles.

Egr vac line connected (egr has been replaced... twice) Masses of white smoke through the exaust. I believe the EGR opens the valve when idling or at low rpms? If sat at a traffic light at idle for a few seconds its as though something is building in the engine and all comes out as white smoke when I pull away.

I left the car on the driveway idling for 5 mins. Went to pull away and filled my street with white smoke. In my eyes when the egr valve is allowed to open (at idle) something is getting into the intake and causing the smoke - help please.

Apart from this the car has no issues, just need to get the CEL off to pass the Mot!

3 minutes ago, Jim666 said:

just need to get the CEL off to pass the Mot!

You don't actually. Your car is early enough to be exempt from this requirement.

From the MOT manual:

8.2.2.2. Opacity

Engine malfunction indicator lamp (engine management light or ‘EML’)

Turn on the ignition and check that the engine malfunction indicator lamp (MIL) illuminates and then goes off. On some vehicles it will be necessary to start the engine before the MIL goes off.

You need to inspect MIL fitted to diesel vehicles including hybrids with 4 or more wheels and first used on or after 1 July 2008.

[My reddening of the red bit]

MOT inspection manual: cars and passenger vehicles - 8. Nuisance - Guidance - GOV.UK

You probably do need to disguise the fact that the vac hose is disco'd though, otherwise it should fail on modification or disablement of an emissions system.

Edited 14 August, 202514 Aug by Breezy_Pete

Thanks for the reply Pete,

Wow thats interesting, had no idea. Guess i could jam something down the vac hose and connect it further up.

Does having the egr disconnected not mean it could fail emissions? I guess its operation doesnt impact what comes out the exaust though?

Its just slightly concerning knowing the issue is present. Its like a light switch, if its connected smoke, disconnected no smoke.

Jim

4 minutes ago, Jim666 said:

Does having the egr disconnected not mean it could fail emissions? I guess its operation doesnt impact what comes out the exaust though?

EGR operation actually tends to increase particulate emissions (which is measured at MOT; the only emissions measure for diesel cars), but it decreases nasty, poisonous NOx emissions (which isn't measured at MOT).

Sounds like your car is emitting a whole lot more of something when EGR is active, so you're probably doing everyone a favour by temporarily disabling it; but yes, do it subtly, and don't whatever you do discuss illegal stuff on the internet! 😆

Get the fault diagnosed properly, then you should be able to re-instate the factory emissions set-up.

White smoke on diesels is unburnt fuel, I think? That should be a clue, but I know next to nothing about diesels and what goes wrong with them.

White smoke can also be coolant getting in the combustion chamber.

So, if the EGR operating causes white smoke, it’s possibly a leak in the egr letting coolant into the pipe work back to the chamber.

How’s your coolant level? Any loss visible? Though it’s probably doesn’t take a lot, so may take time to be noticeable

Thanks for the reply Mac.

I thought the same, immediately suspected a head gasket or something similar. Coolant has held perfectly for thousands of miles so am thinking its not coolant related!

It seems to be something to do with allowing the exhaust gas back into the intake is causing the smoke? For the life of me cant think what.

On my 1.9tdi BXE there is an EGR cooler at rear of engine. Not sure on the BLT Theres a small plastic valve then the EGR If yours is the same It could be coolant getting in to engine/exhaust that way if its leaking. I assume it would only let coolant in when egr vaccum pipes are connected as on mine the small plastic valve opens the cooler.

Alasdair