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Problem VECTRA Diesel whistle?

Hi folks,

This request for advice refers to a 1998 Vectra 2.0 Litre DTH Diesel Turbo Ecotec engine with 110K+ on the clock.

After running just fine for the last 15K since I bought this vehicle, the engine now produces (over the last 100 miles or so) a very noticeable high pitched whistle (variable frequency - turbine like) when pushed hard at RPMs above 2,500. The noise vanishes if I reduce throttle pressure even without reducing road speed. No such noise arises if I get to the same speeds gently with slower acceleration.

Any experiences would help to diagnose this. It's my first turbo diesel and I have been very happy with the engine after spending some time rectifying oddities when I first got it - like EGR valve and airflow monitor unit. I have grown to love the characteristics of a modern turbo diesel and this vehicle suits my needs perfectly.

The Engine management light does NOT come on under these circumstances and I am guessing at either exhaust leaks around the waste gate or manifold or, perhaps, something VERY expensive with the turbo.

My only clue is that the sound drops away fast with throttle - not speed - reduction, whereas I would have thought anything chronic with the turbo would continue with the turbo still spinning fast.

Could I temporarily disconnect the vacuum pipe to the waste gate actuator (and block it with something) to road test it or is it immediately likely to damage something like that?

Direct experiences with this engine would be most welcome. It is pretty difficult to get good access to the manifold with the turbo in place to investigate it while running and, anyway, it does not happen under light loading. Thus, revving the engine with a stethoscope at the manifold is unlikely to help.

As always, TIA,

Tony.

Reply to
Tony
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Sounds very much like Turbo bearings and the mileage is about right for it. Should be around 300quid for a re-con Turbo.

Matt

Reply to
**-**

That seems a VERY short life for the Turbo. I read many postings here indicating much longer turbo lives - like 250 to 300K. Anyone else with Vectra experiences in this area?

You could well be right but I am hoping against hope that that's not it!

Tony.

Reply to
Tony

Sounds (!) too me like a an air duct pipe is loose. Have a close look and follow the air intake piping right through. I suspect that you will find a loose or broken worm drive clamp. Dave

Reply to
Dave Spam

Dave, I did what you suggested and it has greatly improved matters. I can now hear the same noise but it is MUCH quieter. I don't feel quite sure that it is cured as we have had much colder weather here for a few days and perhaps the oil is thicker in the turbo when the input air is colder. If it stayed as it is now I wouldn't be bothered.

Are there any turbo bearing diagnostic tricks? I took off the aluminium air input snail to look at the compressor centrifuge - God isn't the input rotor tiny, about 2 inch diameter or less. It's hard to believe that something so tiny could have that effect on perfomance

- amazing! I used to work on Marine Diesel Turbo blower manufacture as an apprentice in the 1960's at Engish Electric in Netherton at Liverpool. Those varied from about 1 to 4 feet diameter rotors.

The leading edges of the input compressor blades have suffered some small damages. Like they have hit some hard sugar-sized grit particles. No bits are missing - just some rough burrs along the edges, say, 5 to 15 thou (inches) in magnitude. The danger with smoothing these down is that the rotor balance could be lost and anyway the performance is just fine. The snags with leaving them is that they can set up vibrations in the airflow and the blades and cause noise. It may be typical for 100K miles use. Perhaps it's been run without an air filter at some time. Can ice particles form in the air-intake pipework in the frost? This would be common to all turbos so I wonder what normal blades look like after this sort of mileage?

Anyway, I was just in there to inspect, so will see how it goes - with fingers crossed.

If you took off both snails, the whole turbo is surprisingly small and would fit in the palm of your hand apart from the cast foot to mount it onto the exhaust manifold.

Reply to
Tony

Lovely bits of engineering aren't they. Economically , leave em alone till they die.

Reply to
Duncan Wood

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