New R29S With 1900 RPM Rev Limit

[Feisty1]

Motor has 25 hours (D4 320) took it out yesterday and only able to get 8 knots @ 1900 RPM. Trip planned Thursday and will be put on hold if I can’t figure this out. Thanks for advice on this one.

Joe

 

[S. Todd]

I had a similar issue and got an error code on the Volvo display. It was simple fix - change the primary fuel filter. If it gets clogged enough fuel can not get through and the engine shuts down to a slower RPM. (I did not know what the error code translation was so I paid a marine mechanic to contact Volvo and figure it out.) Our issue happened at about the same hours on it as yours. Ours is also a D4 320.

 

[BB marine]

It is hard to believe that a new boat would have a WOT issue. Codes? It sounds like the turbo is not spinning up. What are the boost numbers when at WOT? No turbo, usually engine will turn 1800 to 2000 rpm. If it is new have your dealer take a look at it. Warranty for sure!

 

[Feisty1]

No error code. Volvo tech did 25 hour service today And looked for turbo issues. He tightened things but takes 30 minutes to get out of the harbor to open up the throttle, so he did not attend and issue not resolved. Not sure what the boost numbers are, but will check tomorrow. Will be putting in calls to RT and Volvo mechanic tomorrow as well.
Thank you both for your input!

 

[tlkenyon]

Get a vacuum gauge for your primary fuel filter. Racor sells then for less than a hundred bucks. It will tell you if there is an obstruction in the fuel line. Being a new boat, there might be construction debris in the tank that is plugging the fuel line. It is probably not the filter. I just got done with this problem myself.

 

[Feisty1]

Issue resolved. 1900 rpm is when the turbo is supposed to kick in. With Tim’s advice at RT, I pulled the elbow, etc. to inspect the turbo blades. It wouldn’t turn more than one revolution, so cleaned it up, but didn’t help free it up. I made sure the blade was not in the stuck mode (sticks at 12 o’clock, so set it at 6 o’clock) and put it back together. This did the trick. Boost pressure was at 20psi at 17 knots. Half dozen tests of idle to cruise and all is well!
Thanks to all for the input.

 

[BB marine]

When I saw your previous post that it takes you 30 minutes to get out of the harbor before you can give it some throttle I thought "yes it is a coked up turbine blade or housing." I think this is relatively early on in hours to have this coked up enough that the blades were sticking. A few things cause the blades to stick.(1) Coking from continuous low engine rpm operation. (indication would be black soot buildup on the blades and housing reducing the clearance for the wheel to turn) (2) Sea Water injection from water backing up from the exhaust riser. ( indication would be evidence of some rust in the turbo housing bore. The combination of rust and coke build up reducing the clearance for the wheel to turn.) This happens in boats with engine installations set low in the compartment, recommended riser and exhaust hose elevations are marginal when compared to the engine manufactures recommendations.(3) A turbo that has to much shaft deflection, bent shaft, bent wheel, damaged bearings. All issues are easily diagnosed when you pull the riser off and inspect the turbine wheel of the turbo. In your case I am assuming the wheel and housing were coked up from the 1/2 hour idling to get out of the harbor. To remedy this when you get out of the harbor activate the turbo run it up to 3000 rpm for a few minutes exercising the turbo. Then return to your normal cruising speed. If your normal cruising speed is below 1800 rpm throttle it up once in a while to allow the turbo to spin up.

 

[Someday*]

My r29 2022 with the 320hp Volvo limited at 1900 RPM’s just yesterday. Hopefully it’s the turbo and under warranty…just over 50 hours on it.

 

[Feisty1]

Brian was spot on with my turbo issue, which sounds like your issue as well. I run at high rpm’s after idling out of the harbor then bring down to cruising speed. No issues since resolving. I reached out to the Volvo shop and they said if it happens again, to leave as is and give them a call. You may want to have Volvo correct it if your turbo is still locked up. Best of luck to you.