Volvo D2 75F Waste-gate stuck

[Downeaster]

Hi all - did anyone ever settle any of this? My D2-75F wastegate is frozen. I'll be trying to free it up once I get the exhaust riser removed. Any tips for freeing it?

Also - this topic has various threads on various forums without any solid resolutions. I had a diesel mechanic do a quick check of my turbo and didn't even mention it. To add to the mystery I can't even find any of the wastegate parts on the VP D2-75 online parts catalog.

[ohthetrees]

I have maybe an unsatisfying update:

I hired an official Volvo mechanic in Port Townsend to diagnose two oil leaks on our engine, fix the turbo, and replace the sail drive. $$$. After all was said and done, I would give them a B- and I would not count on everything they said being gospel. Their first oil leak diagnosis turned out to be bogus, but eventually they said one leak was due to stuck wastegate causing over pressure which in turn drove oil out intercooler weep hole. I don’t know how plausible this really was. In any case, they removed the turbo, and were able to free up the waste-gate with nothing more than cleaning. It did seem to help the oil leak a lot, but not fix it entirely. They absolutely refused to contemplate that the exhaust elbow could be obstructing wastegate range of motion. They said it is in spec, though it seems only to be able to move a millimeter or two. When I asked, they were unable to provide a source for this “spec“. In any case, my wastegate seems to be partially working now even with such a small range of motion, and seems to have helped one of my oil leaks. Next time I’m doing a big service I may grind the corner off that casting. I just can’t imagine that it would hurt anything being able to open a little wider.

[Downeaster]

Thanks for the update. Yeah, I also had to replace the sail drive which required complete removal of the engine. Only 1600 hours... I will second your '$$$' comment

[pbmurray7]

I just tore down my turbo and replaced the exhaust elbow on my D2-75F. The boat is a Tartan 4700 2014 and the engine currently has 2200 hours. Initially, I ran the motor at 2000 rpm, which was too low and caused the turbo to build up deposits. I had it removed and cleaned twice, before it was recommended to run at 80% of max, 2400. Since then, the turbo has remained clean, but the waste gate was frozen shut....not from diesel deposit, but from rust build up from the cast iron elbow. I just purchased a stainless elbow and installed it yesterday and my engine sounds like sewing machine again. The cast iron elbow was 2/3 blocked on all three ports, and the engine began overheating at 2600 rpm. The Turbo side of the unit can be detached from the compressor side and cleaned out entirely with a needle gun....will look like new. That being said, I just purchased a complete after-market turbo for $895 and now have a spare. Do yourself a big favor and get rid of the cast-iron elbow! My boat motors at 8.1 knots with a flexofold 19" diameter prop.

[ohthetrees]

I’m sorely tempted to convert to non-turbo, which is basically just a D2-50. Even with my 50’ boat I seem to have more than enough power, and typically run at a higher rpm than I’d like to keep the turbo happier. I usually run about 1800rpm. I’d often like to run 1600 to conserve fuel, or when
motor sailing, but I don’t to save the turbo. The most I ever run is about 2000rpm, more seems like more power than I need, and a waste of fuel as I’m already bumping against hull speed. I only run harder (I max at 2750 rpm) to clean out the carbon build up from time to time, and it is far more power than I need.

I asked in another thread a while ago, but has anyone heard of removing the turbo on one of these? I really think it would be enough power without.

[Kuno]

I used to run the engine at 1800 rpm which is 6.5 to 7 kn and very little noise and vibration. But with the over cooling in the exhaust elbow it creates a lot of carbon buildup and corrosion in the elbow. Last fall the turbo actually seized up with carbon deposits. I managed to free it up and install a new Stainless steel elbow this summer. The engine runs fine now and we run it at 2000 to 2100 rpm which seems to be ok except more fuel and noise.
I installed a Pressure gauge after the turbo. The turbo only starts to produce charge at 1800 rpm 1psi, at 2000 rpm 3psi, 2200 rpm 5psi, 2400 rpm 7psi, 2600 10psi,
Since I could not free up the waste gate to move freely I will only run the engine to 2600rpm under load.

I ordered the Stainless elbow from www.parts4engines.com for 400 British pound .
When the turbo was seized we still could get to 2600 rpm and 8.2kn boat speed.
I would imagine that the non rotating turbo was creating a lot of back pressure. So if I would remove the turbo I probably would get more RPM. This of course makes no sense, what's the turbo doing in the first place if I get the same RPM and speed with out it.
The question is would the engine keep running happily with out the turbo?
Taking the turbo out would fix the oil in the bilge problem.

[pbmurray7]

Found the turbo doesn’t come into play until 2800 rpm to develop 75 horsepower. At 2400 rpm you get 54 hp without turbo. Also, if waste gate is failed shut you can’t hurt the engine. Would seem pulling and cleaning turbo all the time is a lost cause.

[Kuno]

bpmurray7, That is interesting. It does explain why we still got 2600 rpm without turbo. But the 7psi boost we get at 2400 when the turbo runes must still do something. Hopefully it uses less fuel or burns cleaner. Where did you find this info, or did you measure this on your engine ?

[Downeaster]

+1 on this question. I can’t tell when my turbo is spooling. Is a pressure sensor the only way?

[skipperpete]

Originally Posted by Downeaster

+1 on this question. I can’t tell when my turbo is spooling. Is a pressure sensor the only way?

Nope, you can install one of these and measure the rotational speed of the compressor.

[skipperpete]

Originally Posted by Kuno

bpmurray7, That is interesting. It does explain why we still got 2600 rpm without turbo. But the 7psi boost we get at 2400 when the turbo runes must still do something. Hopefully it uses less fuel or burns cleaner. Where did you find this info, or did you measure this on your engine ?

Keep the turbo Kuno, it raises more problems than it solves if you remove it... you need an adapter to rejoin the mixer elbow, reroute the turbo coolant flow, re configure the air intake and finally, blank off the oil supply and return. Easier to just fix the wastegate and find out why you’ve had turbo trouble in the space of 4 oil changes..... a new engine should not be behaving this way.
Your engine is basically a shibaura N44T tractor engine , also sold as Northern lights, Caterpillar, John Deere and a host of other brands. Volvo adopted it and did its own conversion and turbo install with less than encouraging success, the other turbo’s are high up on the engines and usually IHI built and the factory base engines are very enduring and quite reliable.
Yes, you can live without a wastegate but the boost will keep popping off the intake hose... like an automatic blowoff valve. Wastegates are useful on engines in applications where RPM goes from idle to max on a regular frequent basis and the wastegate prevents /limits compressor stall which can compromise the life of the rotorshaft.
How was this not the subject of a warranty claim?
Pete.

[Kuno]

Originally Posted by Downeaster

+1 on this question. I can’t tell when my turbo is spooling. Is a pressure sensor the only way?

You can go to a car parts store ( Princes auto) and buy a T fitting and a 20 or 30 psi pressure gauge for 30$. The easiest place to install this is in the rubber hose between the compressor and the waste gate actuator. It is really helpful to see how much boost pressure there is. You know exactly what the turbo is doing ( or not doing).

[Downeaster]

skipperpete and Kuno - thank you! Very good to know.

[Downeaster]

For those dealing with issues in the future - just a reminder that for some (mine is D2-75F) or maybe all of the D2-75 versions, the turbo is a stock product from the automotive market. I replaced mine for under $800 USD versus a very large $$ number for the Volvo branded version. And it was less expensive than a rebuild. I even painted it green :-) If anyone is interested in my old turbo let me know.

[pbmurray7]

I bought mine but it came from China and was $895.00. Where did you get yours?