A4 2.0 TDI Blue Smoke from exhaust

[Kaskat]

Can you help me, I own an Audi A4 2.0TDI BLB engine 55 plate 87896 miles , it has been into Audi twice now for the same problem:

The problem is blue smoke from the exhaust, not when driving fast but if left ticking over for a little time and then revved, also if you hold the revs at 1800 for 30-40 seconds a slight mist appears then if you give it the revs a cloud of blue smoke appears.

Audi have checked it out on the computer and no faults are shown, on the first visit for this problem, Audi serviced the car (due), changed the EGR valve and two glow plugs then told me that the problem would go away after a few days, needless to say I have done 2000 miles since including two trips to Manchester and back at motorway speeds, the problem is still there and Audi seem to only be able to fix something that show up on their computer system, they say its normal, it's not as I have had the car since new and this is a new development

What do you think

[burble]

Is it using much oil?

[Kaskat]

No more than usual

[Kaskat]

just unplugged the MAF sensor and tested

no smoke

Plugged MAF back in and smoke returns

I think I will try a new MAF sensor tomorrow anyone agree or can tell me how much they cost?

[A4Cab-Chris]

have you got access to vagcom? if so you can checkout whether maf isnt working well.

[Kaskat]

No access to VAG.com however dealer said it was fine on last visit,

I replaced the MAF yesterday however it made no difference, when plugged in I get Smoke especially when the car is cold, un plug the MAF no more smoke, the dealer is not being helpful as the car is outside of warranty (they cannot throw part at it)

Don't know where to turn now

[cruiser647]

Could be an injector issue? One of them isn't playing ball - maybe clogged?

You could try some Millers Diesel Plus and V-Power fuel. Personally, I never put supermarket fuel into any of my cars. I just don't trust them.

[Tipex]

Quite on the contrary to yourself, we only use supermarket fuels in our taxis, and never have any issues relating to the fuel used!

[Kaskat]

I use millers every now and again, did try Red ex fuel system cleaner, did nothing

My car now keeps going into limp mode and yesterday it cut out on a roundabout.

getting desperate may have to trade it in for a BMW

[PetrolDave]

My car now keeps going into limp mode and yesterday it cut out on a roundabout.

What fault codes does the engine ECU log?

Without knowing the fault codes all we can do is guess what the problem might be, you really need to find someone with VAG-COM to rerad the fault codes - get the FULL printout.

[Kaskat]

No fault codes, audi have just had it back for three days, they checked everything apparently, went into limp mode four times on the way home 10 miles

[cruiser647]

Try a different dealer. OR seeing as you are in Herts, try calling Mark Tempest on 01707 392392.

He's an indy VAG bod, (Ex Audi I think). He services both my cars and has done for the last 8 or so years.

[PetrolDave]

No fault codes, audi have just had it back for three days, they checked everything apparently, went into limp mode four times on the way home 10 miles

If it's going into limp mode, then it's a dead cert that fault codes are being stored.

Try to get a friendly local VAG-COM owner to see what fault codes there are.

[Kaskat]

Took it to Mark Tempest, fault codes logged as P0234 overboost, it's booked back in for next week for further investigation

still puffing blue smoke, i guess it's old enough to smoke now

[cruiser647]

Took it to Mark Tempest, fault codes logged as P0234 overboost, it's booked back in for next week for further investigation

still puffing blue smoke, i guess it's old enough to smoke now

Any news from Mark Tempest?

Old enough to smoke now - nah. My Bora has 200K and still doesn't smoke, still doesn't need oil top-ups between services neither. (touch wood!)

[Kaskat]

Yes, Mark Tempest seems to know what he is talking about, it goes in tomorrow for a new turbo, oil feed pipe, oil and filter change.

Rather large bill, would have been more at Audi though, every thing seems to point to the turbo oil seals, overboost, blue smoke etc, if you unplug the N75 valve it drives without smoking at all, however it's like driving a moped

will keep you updated with progress

[Kaskat]

It's fixed at last, Mark Tempest to the rescue as it turned out it was the PCV valve as part of the valve cover, £100 part didn't require a turbo after all.

Thanks cruiser647 for the heads up on Mark Tempest I shall be using him for all the our VAG servicing needs from now on.

[cruiser647]

Good news!

He runs a good company. I cannot fault him! Very fair on price too.

for instance, my A6 2.7T needed a new rad. He got a 'pattern' job first of all (I asked for cheap one ), but it didn't fit!

He spent 2 days trying to get it to fit, but it didn't as it was a different size, until deciding to get a real Audi one.

He still only charged £400!!!

Genius.

Have you had a go in the lovely green courtesey SDI Polo?

[Kaskat]

Wow what a machine that is, a little green shed

[grimsa]

Kaskat,

I am wondering if i have the same problem as you had. Problem is trying to get sense out of Audi. Their parts department say my car does not have a PCV valve and did'nt really know what it was. Suggested new turbo or stem seals.

The symptoms i have are:

1. Occasional blue smoke from exhaust when idling.

2. Slightly lumpy tickover occasionally.

3. Oil leaking around the filler cap.

4. Soot or very tiny oil spots on the back of car (it's an avant)

Otherwise the car drives perfectly. It's a 2007 car with 170BHP TDI engine and 80k miles.

Symptoms sound familiar? Did replacing the valve cover fix your problem completely? Do you remember what the labour time / cost was to fix this?

Thanks. Grimsa.