VP D4 Turbo issue?

[kennyh]

Hi all

I wonder if anyone can help with this….I had my boat with single VP D4-260 out for a shakedown run and I couldn’t get to WOT.

It spools up to 2,200 a 2,400 with a whining noise coming from (I assume) the turbo. The pressure gets up to 100kpa max.

Interestingly I had had the same issue last year after being laid up for the winter. Last year it cleared after a few (5 or so) throttle runs, with no other issues during the year.

At the time I wondered if it could be due to fouling around the exhaust/leg or perhaps even the hull, or just general gunk from the winter in the exhaust system that I managed to dislodge by the revving.

This year, it just won’t “push through it”.

Any idea what it could be?

 

[DavidJ]

Just extrapolating from my KAD43 experience it sounds like the whine is more likely to be your supercharger (working properly) and that the turbo is stuck.
They can unstick themselves as you might have experienced last year but suggest you get it “scraped” out, a relatively easy job if you are a competent diy’er.

 

[Momac]

Sounds like the turbo could need attention and possible reconditioning or replacement.

 

[Sticky Fingers]

My previous boat had D4 engines (300s) and DPH legs. It was very / extremely susceptible to fouling. Legs and props have to be scrupulously clean otherwise the loss of revs and speed is very significant, 5-10kts lost easily. If you have eliminated this as an issue then look elsewhere but I’d strongly recommend you start under water.

 

[kennyh]

Update: The turbo was indeed stuck. I’ve managed to free it with some WD40 and lots of turns.

It now rotates freely for about 1/2 a rotation and with a little bit of resistance for the other half.

I didn’t have time to run it today, but hopefully a good blast on my next visit will prove if it’s resolved.

On the external exhaust side the turbo didn’t appear to foul; I’m guessing the fouling is further into the actual body on the exhaust side.

Any recommendations on how to clean it further / properly?

Pic of the exhaust side attached.

 

[DavidJ]

Update: The turbo was indeed stuck. I’ve managed to free it with some WD40 and lots of turns.

It now rotates freely for about 1/2 a rotation and with a little bit of resistance for the other half.

I didn’t have time to run it today, but hopefully a good blast on my next visit will prove if it’s resolved.

On the external exhaust side the turbo didn’t appear to foul; I’m guessing the fouling is further into the actual body on the exhaust side.

Any recommendations on how to clean it further / properly?

Pic of the exhaust side attached.

I’m glad you have made some headway into the solution. I’ve found that the turbo will come up with any excuse to stick so although you have made an improvement it still may not perform. Generally it’s the exhaust side that just rusts up around the sleeve, there is nothing else inside (except the bearing…..don’t think about that yet) until you get to the turbine on the inlet side. I’ve found that a scrape around on the exhaust side, where the turbine spins, with an electrical screwdriver does the trick. Suggest you try that before going to sea and being disappointed, it really should spin for a couple of rotations on its own.
The inlet side is easy so you could get some fouling there but my money is on the exhaust side.
Been there. Best of luck.