Bluish Grey smoke at wide open throttle

[RonNP]

The other day when I took my boat to WOT I had bluish grey smoke coming out the starboard engine. Both of my engines start up immediately and don't smoke at any other RPM besides WOT. I had my Detroit Diesel mechanic on the boat today and he said I was blowing oil through the motor. I wasn't actually on the boat but the captain I hired to do the test drive stated that was the case.

The boat did great for a trip down from Seattle to San Diego a few months ago but even then we rarely opened up the engines. When we did she did smoke at WOT.

I'm trying to prepare myself that my engine is going to need a rebuild at 2300 hours. The PO cruised with the boat. Any advice or should I just get the check book out and prepare to write a very large check? I should be getting an email today from the Craig at Detroits Only with the news. I will let you know what he says. The engine as 12V71TI.

Ron

[MikeP]

Did it just smoke a lot initially when you went to WOT and then clear after a 5-10 seconds or did it continue to smoke as long as you were at WOT?

[RonNP]

Continuos smoke never stopped. Mechanic said oil was coming through the turbos. He wants to check the cylinder rings and is going to give me a quote. No smoke until you get above 1400 rpm. He said he is leaning towards a rebuild but will let me know after opening her up. My diesel surveyor in Seattle must of been on crack to miss this and quite frankly I can't I believe I missed it

[Glory]

During the survey did you run WOT?

[RonNP]

We did run at WOT. Was told that prior owner generally drove the boat at idle speed and there was probably some unburnt fuel on the cylinder walls. I believed my diesel surveyor and my broker. I'm learning that was a mistake

[Boatsb]

It should have clearned in a few minutes on the seatrial. I'd be discussing this with the surveyor.

[SEVEN]

Ron, I'm surprised that during your survey that they didn't do a wide-open throttle for at least three minutes. How long did you let it run at wide-open throttle on your last work trip? Every DD that I've seen we'll smoke for a few minutes and then it blows off the oil build up and clears up.

[RonNP]

Ron, I'm surprised that during your survey that they didn't do a wide-open throttle for at least three minutes. How long did you let it run at wide-open throttle on your last work trip? Every DD that I've seen we'll smoke for a few minutes and then it blows off the oil build up and clears up.

During survey we did 10 minutes, last week I did about 3 minutes and today around 25 minutes, they finally shut it down after smoke started to fill the engine room. Mechanic is going to give me a full breakdown of costs to repair along with pics today. I couldn't be there as I had patients to see. I'm kicking myself for not doing a more through check on the engines with the surveyor but i just didnt know what to do. I think a compression test may of told me more. Anyways this is going to get expensive quickly.

[Glory]

Ron, I'm surprised that during your survey that they didn't do a wide-open throttle for at least three minutes. How long did you let it run at wide-open throttle on your last work trip? Every DD that I've seen we'll smoke for a few minutes and then it blows off the oil build up and clears up.

Three minutes isn't enough time, in cooler water, this was in the Pacific northwest, it could take 30 minutes to have the temperature creep up to alarm stage.

The "surveyor" should have insisted the "unburnt fuel" burn off, or started a compression test!

My 2 cents.

[saltshaker]

Was this an engine surveyor or a hull surveyor doing a general engine survey? I had an argument with the listing broker when we sea trialed my boat. One engine was 100 rpm light and the other 50. Broker said it was because the bottom needed paint, even though we just hauled and washed it before the sea trial. One engine needed a throttle adjustment but the other had a dead injector and low cylinder. My engine surveyor discovered the problem before we closed. As for WOT test, we ran mine for 30 minutes at full throttle. No smoke or issues other than the low RPMS. That was enough to dig deeper to see what was happening. Good luck and keep us posted. 2300 rpms isn't a lot of hours for those engines, providing they aren't high output. What HP are those?