Yanmar 6LP Possible Turbo Issue

[SteveM]

Starboard engine won't go above 2-3000 rpm under load.
My first thought was the turbo was frozen.
It spins real easy while at rest.

I have not run the boat with a 2nd person onboard yet to actually look to see if the turbo kicks in around 2K rpm.
I'll try to do that this weekend.

Is it possible the turbo is not getting kicked in to engage even though it spins freely while at rest?
Is there something that could fail that "tells" it to engage?

I'm guessing here....but figured someone may have advice before I can go look with a 2nd person this weekend.

[Tony Meola]

Steve

I am sure you have checked your air filter to make sure it is clean. But the other suspects cold be something clogging the exhaust or how about an injector or two? Perhaps something floated up into the exhaust port and jammed up in there.

We have muskrats and otters that are curious enough to do that. Maybe one tried to make it a home.

[Rocky]

https://www.sbmar.com/featured-article/ ... eshooting/

This has reminded me about getting back to the basics and understanding low power in simple terms in the past. I helped a buddy on a 6BTA and found fuel filter with a bunch of junk in it, then all was good rpm back after filter replaced. He needed his tank polished by a service (alge).

[SteveM]

Excellent feedback guys. Thank you.
I shall investigate.
I'm sure once it's all figured out it'll be something simple.

[SteveM]

It's my starboard Turbo. It's not spinning up.

Has anyone rebuilt their Turbos? I see kits out there but wondering if I should just have a professional rebuild it, and purchase a new one, and keep one on hand that is rebuilt for the future.

Anyone know of a service that rebuilds turbos?

[Tony Meola]

Steve

Not to changer the subject but how did you make out with the house and boats? Hopefully only clean up. I assume you were able to get to them after the storm.

[SteveM]

Tony
We did very good compared to many others.
Main house was dry, somewhat. No sea water. We did have two small leaks in the roof, but luckily no over mattresses or furniture.

Only one boat in the harbour stayed afloat. It was a Bertram. See image at link: https://photos.app.goo.gl/PcWsc9iMTV2Bm9KE9

[Rocky]

Steve,
The turbo "spools up" because of back pressure so if you say it spins freely, what is leading you to believe you need a turbo rebuild? There are many more qualified diesel techs here maybe they can chime in. The fueling problem on my friends 6BTA was found with the help of Tony Athens educational experience and I just found that problem by following his tutorial. Have you checked or had a tech check this out before the turbo rebuild idea was concluded? Maybe Bruce can shed some light on subject he is the expert in this field.

[SteveM]

Rocky
The turbo is no longer spinning freely. It's stuck.
Even if I getting it moving, after I run the boat, it's stuck when I come back to the dock.

[Rocky]

Ah,
Got it. That would explain low power!

[Amberjack]

Steve--Advice from my experienced Yanmar mechanic is to run the engines hard, up to 95% of WOT for half an hour on a regular basis to clean carbon from the turbocharger. I had been running my engines conservatively and developing a buildup which happens with these engines. If you can free up your turbocharger enough to get it spinning you might try it.

[Yannis]

My buddy’s Albemarle with 6LP’s, has been told exactly the same thing by his Yanmar mechanic. Or, end each trip with WOT for the last 10 minutes.
I wonder if this applies to 4LHA’s too.

[Tony Meola]

Tony
We did very good compared to many others.
Main house was dry, somewhat. No sea water. We did have two small leaks in the roof, but luckily no over mattresses or furniture.

Only one boat in the harbour stayed afloat. It was a Bertram. See image at link: https://photos.app.goo.gl/PcWsc9iMTV2Bm9KE9

Steve

Good to hear.

Now for the turbo, try spraying some corrosion x on it. Let it sit then see if it frees up. If it does run the heck out of her for a bit then see what happens.

[SteveM]

I'll try spraying it with Corrosion X...but I think I'm going to bring it over to DMS Turbo in WPB. I've read on other threads here and elsewhere that they do good work.

I tend to rarely run it at WOT..I suppose that's an old habit or fear that I shouldn't be over stressing the engines. I'll run them up higher from now on more frequently.

[Amberjack]

I have been told most diesel engines fail from lack of use rather from hard use.

[Carl]

I'm one for running motored up to wot, but for short periods...I'd have a tough time being comfortable running WOT for 10 minute intervals after each days running. Highest cruise for a bit I'd have no issue with.

Somebody who knows please tell me other and tell me why...especially if not so advised in manual.

[Tony Meola]

Carl

An old dock mate had a 32 Blackfin with 3208s. He used to open up whenever he was heading back to the dock for the last 3 miles up the bay. He swore that is what keeper them running without issues. So that was about a 10 minute run at wide open.

Does it help who knows, but if I was trolling for 8 hours, and the run home was short, then I would think cranking them up for ten minutes would help make sure they had blown out any carbon build up. But coming home from. Offshore for 4 hours at cruising speed should do the same thing .

[Carl]

Tony-
I have problems hearing one persons theory with nothing to back it up.
Yes he ran his motor WOT for 10 minutes and believes that is why he has had no issues. But maybe its because he uses the boat often and takes good care of it. Maybe the wheels are setup to run over rated WOT so motors are not quite running at 100%. Maybe he just got a real good motor.
On the other hand, if he didn't run WOT for those ten minutes each trip maybe the motors still would have not given him issues and he might wind up getting a few extra years out of them.
Maybe were just guessing...I know I am. I'm also one to believe that motors should be powered up a bit easy and brought down easy...then allowed to run at idle speed a few minutes to allow them to cool off before shutting down. I can say I did this with my gas 440 motors and they racked up thousands of hours after I bought the boat with almost 2000 hours on them, prior owner did the same...Is it true, who knows.

I'd question the reasoning if only this...trucks with diesels don't run flat out at WOT for extended periods and they crank up plenty of miles.

One thing that does bother me some is that the Cummins manual specifically says not to run at idle speed for extended periods...I troll alot. My thought is to troll a bit then run a bit...but still have some concern.

[Yannis]

Carl, the 6LP’s are marinized Toyota Land c.
These turn high. Possibly, you have to turn them high at the sea too.
You will never be given every justification, however, you're right, no j is not a firm position.

[Carl]

Yannis turning high and running WOT are very different in my book.

[Tony Meola]

Carl

The Cummins manual says not to exceed full RPMs for more than 1 hour in X Hours. Sorry I don't remember how many hours that is , I have to look it up again.

[Amberjack]

The Yanmar manual recommends propping to achieve between 50 and 100 rpm over maximum engine speed (3800 rpm) to prevent overloading the engines. Also operating "at maximum speed for 5% or less of engine hours (30 min every 10 hour and at cruising speed (2800 rpm) or less for less than 90% of operating time".

There are some ESL issues in the manual but the sweet spot seems to be 2800 rpm to 3600 rpm. I also interpret this to mean its OK, possibly recommended to operate at WOT periodically and to avoid extended low cruise.

[SteveM]

Anyone ever removed the turbo themselves?

Looks like four bolts hold the entire thing on.

Bunch of other stuff hanging on to it as well.

I'd like to remove it and bring it to the Turbo repair guy in WPB.

Any tips for removal would be appreciated.