Turbo Or Maf?

[Guest farrje]

I have a 2000 (W) 1.9Tdi Ghia (old version). In all gears, acceleration is smooth until about 2,500 revs after which engine seems to lose interest (although still accelerating slowly). Top speed (on autobahn, natch) is 90 mph.

 

Lots of threads here on maf problems but my dealer - Dagenham Motors in Islington, London - reckons this is a turbo issue. Cost of repair in the region of

[Guest SA Intruder]

Disconnect the MAF, see if it drives any better.

 

If it does, change the MAF. Seems to be about GBP160 from a company known as Lynx (search on Lynx for more detail).

 

Turbo failure rare - they normally fail due to oil seals, not boost.

 

There is a wastegate that can play up - they are cheaper to repace than entire turbo.

[Guest farrje]

Thanks SA. Since you mention the seals, I have noticed that the oil level is high. Too high. Maybe it is the turbo after all. Will do MAF check but do you have any experience of secondhand turbo units? And are there different versions?

[Guest SA Intruder]

Oil level unlikely to affect turbo, unless the turbo oil return is "blocked" by oil level in sump.

 

The oil level would have to be very high to do this...

 

However, an overfilled sump is not a good idea for other reasons... I suggest you correct the level before long.

 

If the turbo oil seals have gone:

 

firstly, assuming they are wearing, you would get more blue smoke from the exhaust, and the interior of the tailpipe may start to get a sticky black residue. Obviously this situation will worsen over time. You may also notice an increase in oil consumption, and a gradual drop off in performance depending on whether the inlet seal and/or the exhaust side seal have worn.

 

Secondly, if the seals fail catastrophically, the engine will either a) run all on its own, at any revs (dependant on the seal failure mode), and the exhaust may glow red. The MIL will also light, since the ECU is not injecting the correct amount (or any) of fuel, yet the engine is reving. This type of failure is very disturbing...the ignition key will not stop the engine, and the only way to do so is to stall it or B) there will be clouds of smoke piling out of the exhaust. OR you may get both symptoms! In varying degrees.