Hi, I’m having intermittent turbo failure on a 2002 1.9TDI Octavia Elegance 110bhp.

I know this topic comes round again and again (and i have read the other posts) but hope this will generate some interest ...

I’ve just phoned a skoda dealer for a price and advice on error code downloads and they gave me the general impression that on the older Octavias the fault codes can be a bit generic and they would have to set to testing components, something that I would enjoy doing anyway. . . .

Symptoms

Engine going into limp mode, always on a long hill under load and mostly in 4th gear around 3,000rpm

Also, occasionally there is a noise like “a person with a cold taking a sharp intake of breath” 2 or 3 times in succession on acceleration up a hill, this causes engine to back off with each noise, does not coincide with engine going into limp mode though.

Action taken so far

·The VNT lever was very stiff and movement seemed limited, I have worked the lever with a dowel rod and a release lubricant and movement has returned, the stiffness seems to be of similar level to our other car (1.9 TDI Octavia Ambiente 90bhp).

·On revving the engine the VNT moves, I have also vacuum tested the long pipe to the turbo which is ok.

·Have swapped the N75 from our ambiente to the elegance car but the valves must be of a different spec as elegance power was very limited with the ambiente N75.

·The N75 valve on the ambiente seems to have a better sound to it, “toc” when I manually sucked the pipes, the elegance one sounded a bit weepy but don’t know if the valve is one way or just restricted flow. I think the ambiente valve let flow both ways, although heavily restricted one way…

·The EGR butterfly valve seems to move freely, and when switching the engine on and off the vacuum plunger moves ok, which moves the VNT up and down ok. (or is that the N75 doing the latter ?)

·Running the engine with the EGR pipe (the one from the top of the EGR to the valve on the bulkhead) disconnected and plugged made no difference, still limped

·I have also cleaned the MAF if that makes any difference.

Has anyone got any ideas for further testing ?

Where is the MAP sensor and can I do any kind of test ? – is this attached to the inlet manifold ?

Any suggestions gratefully received

Thanks

Ed.

Hi

Normally cleaning the MAF is not very succesful as direct replacement is always advisable.Wouldn,t be the MAF anyway.The MAP sensor is located on top of the intercooler which is at front offside.These turbos are prone for having sticking vanes due to being all gunked up.You can clean out the turbo if you are mechanically able to,as replacements are very expensive.It wouldn,t be the EGR but not sure about the N75 though.Of course a diagnostic check with VAG.COM would be better.Hope this helps you a bit:thumbup:

Had exactly the same issue in October last year. They thought it was the MAP sensor but turned out that it wasn't! A diagnostic check came up with code 17965 Air Flow Flap V71 Boost Reg Cntrl Limit exceeded. VNT lever was sticking so I had a new turbo under warranty fitted. No problems since.

Very common on these models apparently. Mine's an 0252 1.9tdi 110. Think there are threads here where some have managed to clean the muck out and have had no problems since.

Yes, what you say seems to indicate over-boosting, which is usually due to sticking VNT. if giving the mech a good working-over with WD40 isnt making it any better you may have a faulty actuator, which usually means a new/reconditioned turbo is required. VAG usually replace the whole turbo unit, but i think Forge have a replacement actuator available for TDI applications.. not sure if it would suit your turbo though, you would have to check with them.

Edit, if you can find someone near you who will scan for codes on your ECU, it will tell you the problem for certain.

it wont be the MAP sensor as the car would be in limp mode permanently as it compares the readings with the atmospheric pressure sensor... i have had this fail on my Furby

Thanks for replies. . .

it does sound like a sticky turbo from your replies. .

How difficult is it to remove ? (i've got the pdf file containing the cleaning method once off). .

I've got access to a pit, but the turbo looks quite unaccessible and daunting to remove. . .

A VW mechanic told me you had to take a drive shaft out to change the turbo. However my local man "around the corner" was able to take the turbo off without removing the drive shaft.

You will need new gaskets, and also maybe a new oil feeder pipe. My bloke was able to reuse my oil feeder pipe, so I have a spare one in my garage - it was a special order item from VW so they would not take it back into stock :-(

A VW mechanic told me you had to take a drive shaft out to change the turbo. However my local man "around the corner" was able to take the turbo off without removing the drive shaft.

You will need new gaskets, and also maybe a new oil feeder pipe. My bloke was able to reuse my oil feeder pipe, so I have a spare one in my garage - it was a special order item from VW so they would not take it back into stock :-(

Please let me know if you manage to solve this problem as i have exact same fault,under heavy loads,up hill low gear. Turn the ignition off and it returns to normal. I have fault codes 17956 and 17563. Thanks.

Also, occasionally there is a noise like �a person with a cold taking a sharp intake of breath� 2 or 3 times in succession on acceleration up a hill, this causes engine to back off with each noise, does not coincide with engine going into limp mode though.

Mine used to make that noise sometimes too. More so when on the flat and when cold, and just after I set off from work.

I took my turbo out from above instead (inlet and exhaust manifolds come off). Apparently you can just get the turbo out without removing the drive shaft, but it must be *very* tight.

turbo comes off thru the top with the inlet mani off. it does sound like you have sticking vanes. what your skoda dealer was trying to tell you was that the fault code would only say it had exceeded the boost levels and not the reason why it had done so so futher testing would be needed basically.