Hi all,

I'm a former fabia vRS owner, but my problem concerns my 2005 Passat B5.5 PD130 (AWX engine) estate, since the engine is pretty much identical (albeit 90 degrees around) as the Skoda PD130s hopefully someone here might be able to help...

The problem:

- The power from the engine is lower (not like an inoperative turbo kind of low) - maybe 70% of what it should be up until around 2200rpm, then it gets all the torque back and takes off like a rocket (much steeper change than normal turbo lag). There is also very bad engine vibration on idle (all the hoses etc jumping around if you watch the engine) and all the way up to about 2000 rpm, upon which all the vibration disappears completely. The vibration only happens when the engine is hot, it isn't noticeably there when the engine is cold. The vibration is worse under heavy load/acceleration and sounds slightly resonating. It's not coming from driveshafts/suspension etc.

Other info:

- The problem started at the time when I noticed two things: I'd slightly overfilled the oil (which I fixed), and I also noticed that the timing belt was slightly loose. Now this looseness wasn't bad, I read the torsion angle on VCDS and it was only at 1.7 degrees (up from the normal 0.6 degrees). I had the cambelt tensioner adjusted and it's been fine for the last 5 months

- The car has for a long time emitted some unburnt diesel (ie it stinks). I think there may be a slightly faulty injector perhaps which dribbles out fuel after the main injection, but VCDS shows all injectors well within deviations

- The MPG is pretty normal - perhaps slightly lower than optimal, I get about 46 mpg measured at the tank (factory spec on this car is 47.9) . The computer reads about 4% more optimistic

- It starts, idles and drives reliably - just with the power loss and vibration

- There are no faults on VCDS (apart from the EGR which i've disconnected)

- It doesn't smoke at all (with the EGR disconnected)

- The car's done 130k, but it's been regularly serviced (with the right Quantum oil since I've had it)

- Cambelt, pump and tensioner were done at 100k

What i've checked (ie what it's not I think):

- Timing: I've tried setting the torsion value on different settings between 2.2 degrees advanced to 2.2 degrees retarded. I've currently got it set to 0.6 degrees advanced which is normal. The vibration does get less with retarded timings, but it's still noticably there and when retarded I lose even more power. When the timing is set, it stays there so i'm sure that the timing belt etc it ok

- Turbo. I've tried disconnecting the vacuum to the turbo (so it's disconnected), however I still get the vibration. Boost is fine and i'd replaced the N75 last year so I'm sure this should be ok (ie I know what it felt like when faulty)

- EGR. I've disconnected this. Car generally drives a bit better, but it doesn't affect the power/vibration

- Flywheel: Not checked, but the vibration is there when driving in all gears up to 2000 rpm. If the DMF was failing, i'd expect the vibration to go when the clutch was engaged?

- I've logged all the usual stuff (MAF/MAP/IQs etc) while driving, and there was nothing obvious in the values

- I couldn't hear anything obvious listening to various parts of the engine when idling (with the engine top cover removed)

- It's not really got worse or better in 5 months, but it worries me and is annoying that I'm lacking power and have vibration

So remember that the vibration is only really bad when the engine is hot, and I'm lacking power <2000 rpm.

I'm not sure what else to check... I don't believe that it's general engine wear, as i'd expect it to be worse at cold (there's no sign at all of blue smoke, piston slap etc etc).

Things I've wondered about are:

- Could it be related to the camshaft, or the PD injection stroke adjustment (injector cam followers)?

- Could it have damaged something when the timing belt was slightly loose? I'd find this hard to believe as when it was in this condition, the torsion value only changed by about 1 degree from normal

Any help of things to check or pointers would be really appreciated!

Many thanks

Lee

Oh - and i've had a look at the camshaft. I couldn't see any obvious scoring or wear (hard to compare to a good cam though as I don't have one)...

Despite the complete lack of interest in this topic (thanks...), here's what I did:

Basically I did the "Mr Muscle oven cleaner" turbo cleaning, and the vibration / loss of power under acceleration is now pretty much gone, and it's much smoother without the "strangulation" around 1800-2200 rpm! I only managed to get half a can of oven cleaner in, so I might be tempted to repeat the procedure so that the turbo is as clean as possible!

I still have some vibration at idle, though this doesn't seem to get worse with temperature now. Perhaps it's the alternator pulley, but it's not too bad so I'm not that concerned!

Lee