Yanmar 4by2 150 wastegate

[ngleadow]

We were getting a overboost alarm on our engine when we hit 3000 rpm. Using a pressure test, the problem has been traced to the wastegate actuator (the round silvery thing beside the turbocharger). Unfortunately, Yanmar does not sell the part seperate from the whole turbocharger. Has anyone been able to find this part.

 

[Salty7]

I have the same engine, can't answer where to find the actuator separately. The actuator has a hose connected to it that fell off on mine. Check carefully that the hose is intact and properly connected to the nipples at each end. My turbo boost went crazy when the hose fell off, it fell off because it was made slightly too short at the factory and clamped with clamps too weak to keep it in place. I replaced it with vacuum hose and a couple of decent clamps, no problems since. I forget if the actuator is just pneumatic or electro-pneumatic but do remember the importance of that hose. It runs from the actuator to the bottom of the turbo somewhere, they must use the turbo to create vacuum for the actuator, I think it actuates the waste gate. If the waste gate can't bleed you will definitely have excess boost pressure at higher rpm.

 

[ngleadow]

This is definitely a problem with the wastegate actuator. I had it tested, and it was not functioning properly. The issue is trying to find a new actuator without having to buy the whole turbo. Yanmar does not supply an actuator without the turbo attached.

 

[nzfisher]

This is a Yanmar part not a BMW part? If BMW you might try searching EBay Europe and see if you have any luck. Just a thought. I believe the engines are still used in Europe.

 

[ngleadow]

The turbo on the 4by2 is a Mitsubishi turbo charger. The engine is a BMW engine that has been marinized by Yanmar. I am now looking for the Mitsubishi actuator. What a hassle!

 

[Brian B]

Try this comany https://turboturbos.com/collections
They sell a replacement turbo for the engine, maybe give them a call and see if they can help out with a wastegate.

 

[knotflying]

Did you check the existing wastegate for manufacturer name or part number?

 

[ngleadow]

Thanks for the suggestions. I (and our mechanic) have tried every source, used all the part numbers in our search, contacted companies that rebuild them (it is a sealed unit so can't rebuild). One possible source left. We'll see.

 

[Brian B]

Marathon Diesel had a Yanmar 4BY2 they were parting out some time ago. Might be worth a call, here’s the website
https://www.marathondiesel.com/

Please let us know how you make out with issue.