Diesel engine issue

rszarka

rszarka

Member
Mar 19, 2011
982
Sydney Australia
Boat Info
1999 Sea Ray Sundancer 540
Engines
Twin Detroit Diesel 8v92TA
Hi Everyone

I have twin diesel 8v92TA engines. My port engine was fully rebuilt under 100 hours ago!
My port engine is slowly losing oil but i am finding none in the bilge. I noticed an oil like film, dunno if it is oil or fuel in the outflow of the engine. Its light but it is there.
The port engine starts right up and runs fine without any problems. It is a bit smokie, black smoke and if i push the throttle way up it makes a huge puff of smoke. I know some smoke is normal but this is way more than the starboard and I'm sure what is considered normal.
Should i be worried about this, does any of this sound like indications of a serious problem or like something small like too rich of a fuel mixture.... Its pretty strange some sort of fuel or oil is coming out in the exhaust.
The only thing i have done with the engines was change the Racor filters recently. The fuel is all clean and fresh.

Any insight would be great
Thanks guys
Rob
 
Not sure how Detroit's break in, but it could be normal for them to burn a little oil as they break in, but you should check with someone that knows. The black smoke and the sheen on the water sounds like a fuel supply issue. You may have to have your injectors adjusted or cleaned.
 
Black smoke is very often an indicator of an air inlet restriction. Have you looked for any restrictions in the intake system? Something as simple as an oil soaked or dirty air filter, or insufficient boost pressure would result in black smoke as well.

Dale
 
Do your engines have fuel coolers? Could be the reason for the oily discharge. If so, temporarily bypass it to see if it stops. You just need to get a coupling to connect the 2 fuel lines.
 
You might want to go over to boatdiesel dot com and join for the $25 yearly membership fee. You can then do a search on your specific motor - your issue has probably come up on that forum before. There are some very knowlgeable diesel guys there.

Best,
 
Call a good Detroit mechanic. We had similar issues a few years ago, and kind of ignored it. We had some bad injectors, they washed out 3 cylinders. $11,000 later it was fixed. Don't wait, simple fix now, not later. Good luck
 
Because of the risk and the potential costs of Detroit repairs.........you just think Cat and Cummins parts are expensive.........almost any cause for excess smoke and oil on the water is a concern. These are 2 stroke diesels and the potential for washing out a cylinder is 2x greater than with a 4 stroke, excess blow-by means combustion gasses getting past the rings and the list goes on. The combination of black smoke....unburned fuel (from restricted intake air or faulty injectors), coupled with oil consumption, then you add visible sheen on the water and the picture isn't a pretty one. Your next move should be to get a Detroit mechanic on the boat, not searching internet forums for guesses...........guessing is all we can do; we aren't there and can't see what is going on.
 
Hi guys

Many many thanks for the info and advice. As always I took your advice called a Detroit mechanic right away. He is coming to the boat on Tuesday. He seems to believe after asking me many many questions that I may have a faulty injector. Also because the smoke is minor not excessive accept at high revs he does not believe I am dealing with a big issue. He said if it was several bad injectors etc the back of the boat would be black from smoke. I checked out his credentials he has 14 years Detroit xp and is factory trained. So Tuesday he is coming
Out will diagnose and I will get the problem fixed ASAP. Not taking any chances with this. Apparently it could be any number of things including carbon build up in the turbo. So getting it tended to this engine has under 100 hours on it so surprises I am having issues.

Again many thanks to all of you for your time and your help. CSR and it's members are great!
 
Jr: i read the link that you posted and somehow doubt it is bobby just because the engine is a fresh rebuild and the diesel engine surveyor that i hired said to me this is ridiculous and i was like great its shot??? he said no "he was doing a borescope at the time" he said the condition on this engine is incredible for its age not one scratch on the pistons or cylinder walls they are brand new he said .... so from what that article said i don't think it could be that... I did have an incident in florida where the engine ran at idle for an excessive time! It did not overheat or anything but it is my understanding it is very bad for one of these to run at idle for hours! Maybe there is some kind of carbon buildup now etc? Or maybe back to your theory the blow by is being caused by carbon build up?
 
So just wanted to post as much as info as possible here because I know the more info the better the chances of you guys having an idea of what is up. So I am out on the water today. When I started the boat up from cold there was quite a bit of diesel in the water initially I mean to the point it was almost like when you spill fuel in the water. But here is the interesting part as soon as it warmed up all the smoke disappeared and no more fuel was in te water outflow. I mean zero, both the smoke and the fuel completely cleared up once warm. I have moved around quite a bit today and not one other time has there been smoke or fuel in the outflow. So it seems like once she is warm it's clear like it should be. The engine starts right up first push of the button. Runs dead smooth and has proper power etc so dunno this is weird! Oh I keep my engine room spotless get right on any corrosion rust treat and paint. If the paint gets dirty repait right away. Apart from it looking like new engines the other Obvious advantage is any oil leaks etc I see right away! Will I have noticed where the port engine inboard turbo joins up to the exhaust there is little droplets of oil like a fine mist type thing as if there may be some sort of leak there but in the form of a very fine mist! Dunno if this has any relevance to all of this?
 
If you have a faulty injector, it isn't atomizing the fuel properly but is spraying droplets instead. Those droplets don't ignite and are not being burned fully, so you get diesel fuel out of the exhaust ports and blue smoke when you start up. But, the bad news is that diesel fuel is a solvent for lube oil, so the unburned fuel is washing out the cylinder walls and the lower cylinder isn't being lubricated properly so every stroke the engine makes wears the cylinder walls, piston rings and piston skirt. IF there is a bad injector and IF you continue to run the engine, you could be looking at a major repair to remove the head and install a new liner, piston and rings in the cylinder with the bad injector.

The xV92 Detroits are 2 stroke engines, not 4 stroke like Cat, Cummins, MAN etc. So you get twice the fuel spray in every minute the engine runs that 4 stroke diesel owners do. Do yourself a big favor and stay at the dock with the key in the off position until your mechanic check the engines.
 
Wow ok will definitely take that advice that engine is jot being started again until after the mechanic fixes the problem!! Once we talked about it all he said it was no problem to take the boat out this week end!! Maybe I should get a different mechanic!! Thank you for the advice and I will take it! I am out now but only a few miles from home will go in on my starboard engine only. This is not unhealthy for the boat right?? Now I'm worried, why did that idiot say it's fine to use the boat!!

Many thanks for the warning, that engine is not running again until the problem is fixed!!
Rob
 
As long as you have a crossover for the dripless seals you can run on one engine. There will be a hose from one dripless to the other. If that is there you are OK, if not you run the risk of damaging the dripless on the engine not running since it will still spin with no water running through it.
 
Well I am out on the harbor, quite wicked weather actually very strong winds. Had a trip planned for my sister and family who came down from Canberra I told th
It would be rotten but they wanted to go anyways. We are on the hook in a sheltered bay but it's still bad! 50 km/h winds out there. How do I figure out if I have a dripless cross over? What would I look for on the engine, I will go through the user manual and see if I can find out if I can run on one engine! Will be tricky in this weather either which way! I mainly run around nice and slow as it is but from the way it was explained it does not matter slow or fast.
Just so I understand this right the diesel breaks Down the motor oil when it is not atomized correctly and the cylinder wears? Why the hell did that mechanic who diagnosed the problem as maybe one faulty injector say it was ok to use the engine! Stupid! I am not using him now, will call someone else!! So yeah we are supposed to head in late afternoon. 50 km/h winds one engine possibly this should be an interesting day. Maybe I should just call seatow or stay here until the weather clears!
 
The dripless is around the shaft where it penetrates the bottom of your boat. If there are more than one hose attached you most likely have a crossover.
 
The dripless is around the shaft where it penetrates the bottom of your boat. If there are more than one hose attached you most likely have a crossover.[/QUOTE]

Thanks :) I have two hoses coming out of the sleeve around the shaft, I have taken a photo uploading it to photobucket and will post it herein a minute.

rszarka
 
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