Hi all.

Just hoping for a few pointers. My 1.9tdi is very smoky now under gentle acceleration it has been slowly getting worse over the last 6 months. I have tried injector cleaner etc. It starts well then after a couple of seconds almost runs on 3 cyls. It clears itself out then runs ok but is very smoky under all acceleration. Turbo seems to be working ok, It doesn't seem to be using oil iether. MPG is down slightly.

I use mainly asda fuel I have kept it well serviced.

The exhaust was broken and I thought that was the cause but no.

It has done 140k miles.

I think that it is fuel not oil but any common problems would be greatly appreciated.

Thanks

Tom:confused:

Personally I never use supermarket fuel cos it doesn't have the same detergent packages as brand name fuels do.

With you running the 110, I'm wondering if the VNT is working correctly. Do you ever use full power and let the car run up to maybe 3_500rpm or so?

Can you answer these to help people have a bit more information:

- What colour is the smoke?

- When did you last change the air filter?

- When did you last change the fuel filter?

- Have you ever changed the MAF?

Ok thanks for your interest.

I do use full power on a reasonalby regular basis 3rd and 4th gears up to 3500.

The smoke is a brown colour and smells of fuel when just started.

air and fuel filters changed with timing belt 1500 miles ago.

air flow meter changed about 5000m ago.(I was lacking power big time)

The problem has been slowly getting worse over the past 10000miles.

I do use injector cleaner regularily.

Tom

What injector cleaner do you use?

I'd stop using that for a start as some of them can strip things a bit too much.

What oil is in the car, is it the correct one and are you using much oil?

TBH I doubt it is the oil but worth checking.

Might be worth getting the coolant temp sensor checked out as it could think the car is cold when it isn't so over fuelling.

After that I would think it's probably worth getting any independent specialist to give it a look over.

I have used various cleaners. Wynns and stp .

The oil is good quality general purpose from my friends garage where I do my servicing.

It hardly uses any. I havn't had to top up between services.

Will look into the temp sensor. The temp guage seems to be working ok.

The car sounds like it is hunting when started on a cold morning and left running while I scrape the windows. Lots of unburnt fuel smoke.

Thanks for your pointers.

I will keep trying.

Is the oil VW 505.1 and of 5/30 or 0/30 viscosity.

If not it's the wrong oil, which could be causing problems in things like the turbo etc.

Temp sensor sounds like a plan, and I wouldn't use either of the injector cleaners you listed myself. Millers diesel clean/powerplus/power sport 4.

Guess you could also look into cleaning out the EGR etc but I am not that familiar with the process myself.

Looks like the oil is wrong then.

I'm afraid I don't know what an EGR is.

It has to go in for it's mot this week so hopefully they will know what is wrong.

Cheers

EGR - Exhaust Gas Recirculation (valve)