D4-260 won’t rev beyond 2100 rpm

[gwishon]

2015 R-29S, lift kept. Boat was unused for about six weeks, now moving throttle past about halfway results in no increase in rpm. No engine codes or alarms. Thinking it may have been the result of water in fuel (tank 2/3 full), changed both fuel filters and water sensor. No joy. Prop visual inspection ok. Coolant temperatures normal. Have scheduled visit by Volvo tech but will be two weeks out. Only unusual indication is that cockpit helm shows a flashing “!” on the binnacle (but not on the main helm binnacle) and the cockpit helm lcd display is blank (inop).

Any ideas?

TIA

Gordon

 

[BB marine]

Possibly a loss of communication with the Helm. The engine has lost communication with a helm station. Engine power is reduced.

 

[gwishon]

Thanks. Any suggestions on how to diagnose/confirm?

 

[bill46]

Flashing indicates an error, scroll main display to right to error screen to find out. Might reset by powering down. Leave battery switch on, shut down both engine buttons, wait and power up. That has removed error message for corrected conditions for me.

 

[Dale777]

Gordon,

The problem sounds like it might be a lack of adequate turbo boost pressure.

You can display engine data on your chartplotter. Select turbo boost pressure from the engine data choices to be shown on your chartplotter. When you rev the engine, see if the boost pressure is greater than zero. If not, that is the problem.

If the boost pressure does increase, check to see how high the boost pressure is. For your engine, I don't know what the maximum boost pressure should be. But on my D4-300, I notice the boost pressure is about 28 psi or so at wide open throttle.

 

[gwishon]

Scrolling to the right on the engine display (to the “Warnings” screen) shows no warnings/errors/codes. Will try cycling the ignition on/off tomorrow. Will also check turbo boost levels, but am doubtful that would be a cause rather than an effect. In my experience turbo boost only increases under load - in my case the engine is never placed under load, rather, the rpms seem to be artificially limited. I suspect Brian is on the right track but I don’t know how to test his theory (other than to wait for the Volvo tech to run diagnostics).

 

[TBates]

Good morning Gordon, great suggestions posted by others on here as my first two thoughts were to check the warnings manager, as well as your boost pressure. If the turbo has become stuck, you wont be able to achieve more than 1500-2000 RPM's. Although, this wouldn't trigger an alarm on the aft station like you are experiencing. Please send me an email to timbates@rangertugs.com or give me a call in the office at (253)839-5213 and I can help further diagnose.

Thank you,

-Tim

 

[gwishon]

Did a little more testing this morning with the boat on the lift. With ignition on, engine running, cockpit helm station in command, can operate throttle and helm steering, but have flashing “!” on binnacle and cockpit engine display is blank (so cannot stop/start engine). Main helm in command, turn engine off and cycle ignition to off/on and restarting engine clears the “!” but cockpit display remains blank. Did not test run the boat in the water with cleared “!” yet but will try later today (after drs appt).

 

[gwishon]

Update. Tim Bates from the factory kindly walked me through resetting the engine electronics, which has cleared the cockpit binnacle flashing “!”. Also checked the connectors on the underside of the binnacle and the cockpit engine display. Connections all appear ok, although display is still inop. May be a failed display. Next step will be to remove turbo elbow and inspect turbo operation later today. Thanks, Tim!

Gordon

 

[gwishon]

Final update. Success, mostly. Following Tim Bates’ advice, pulled the elbow from the turbo, reached in and attempted to spin the turbo wheel. It moved only about five degrees. Further wiggling back and forth caused it to break free from the soot deposit that was hanging it up. Cleaned the housing and vanes as much as possible, sprayed with penetrating oil, and buttoned it back up. Boat now pulls strongly up to max rpm, 3450rpm or so.

Cockpit engine display still inop. Will try replacement display through Volvo.

Question for the group. Is service of the turbo a routine maintenance item? Tim says a thorough cleaning by removing the turbo completely and using a brush is is the best approach. I can imagine, though, that this is an expensive service procedure. Thoughts?

Also want to mention the great customer service by Tim Bates and the RT factory. Thanks, Tim!

Gordon

 

[BB marine]

I'm actually surprised that the Turbo was coked up. The D4 has a simple well designed Turbo Borg-Warner K26. It is not VGT type that has a vane plates that can get stuck or a Wastegate. I am assuming that you inspected the exhaust side ( turbine side) of the turbo finding Coke or soot build up. Was there any evidence of water intrusion or rust? One of the positive components of this Turbo is it is water cooled on the Turbine side (exhaust side) keeping the turbo housing at a even temperature regardless of how much power the engine is producing. This can have a negative effect too, it can cause the turbo housing to have coke build up if the engine is not run up to higher rpm's allowing the exhaust temperature to elevate reducing the chance of coke fouling. This doesn't mean you have to run it wide open all the time, it just means if you do a lot of idling and slow cruising bump the throttle up for a while which increases the exhaust temperature burning some of the coke/soot build up off. Other then the symptom Max 2100 rpm I would have never thought that a D4 turbo would have had a turbo impeller stuck. Normally the issue is with waste gates sticking open or with VGT turbos the vane plate gets stuck. The K26 has neither.

The inspection of Turbo is recommended every 5 years or 600hrs. I inspect movement, side to side play and end play once a year when I change the air filter. (compressor side) D3 has a VGT so I inspect movement of the actuator arm that actuates the vane plate. A good Turbo check is keeping a log of boost pressures. Know your WOT boost pressure, high cruise pressure, 2100rpm, 1500 rpm, log these numbers in your log book. While cruising confirm that your boost numbers are still maintaining your recorded figures. If you see a discrepancy its time to inspect the turbo.

On another note about Turbo's. I had my turbo replaced at 400 hrs based on the recommendations of Volvo because of oil in the compressor side of the turbo. I had a hose failure Turbo to aftercooler. This resulted in a oil leak. The theory was there should not be oil in the turbo. Turbo and hose were replaced and after 4 hrs of running I inspected the compressor side of the turbo and found oil. I contacted Volvo and got the general response talk to your dealer. I talked to the dealer and they said Volvo said ...... basically they don't know why. I contacted Garrett the manufacture of the D3 GT Turbo via email. The Garrett representative stated that it is not desirable to have oil leaking past the impeller shaft seals but it happens. The seals are not positive seals. The design rely's on the compressor pressure to help seal the bearing cartridge. Unfortunately at idle or lower rpm ranges the turbo is not spinning up fast enough to build pressure. The oil leaks out and is pulled through the aftercooler and is burned off during combustion. This can also add to additional coking if a lot of extended idling and slow speed running is done. It doesn't mean you can't do this just be where of it and run the engine up for a while to help burn it off.

Good job in troubleshooting the issue and getting the boat back running properly.

 

[gwishon]

Yes, exhaust side. No evidence of water intrusion or rust, just copious amounts of soot and carbon buildup. Engine has just 350 hours. I probably am guilty of running it at too low of rpms, lots of travel through canals to our home/lift. If I had seen this amount of soot on my gas turbo powered car, I would have leaned out the fuel mixture and not run so rich. But this is a diesel. Will now make checking/cleaning the exhaust side turbo vanes a regular maintenance item (it’s easy enough to do).

Gordon