Oil splatters below turbo

[bobk]

I'm going to break this into two threads.

My last engine room check after returning to Port St. Lucie, FL from Baltimore revealed two places which had an oil splatter. I didn't see these the day before, but perhaps overlooked it. Here are two pictures of the splatter on the raw water pipe below the inboard port engine turbo. These are 6V92TA's 425 HP. The turbo's were rebuilt at the last overhaul which is now about 1000 hours back, but the last 700-800 were at 1000-1100 rpm. Do I need new turbos or tightening of something?

 

[Genesis]

Check for oil pullover through the Airseps and specifically the vacuum regulators.

 

[captddis]

That oil supply line looks scary too. Pull the cold side off and clean the mating surfaces then lightly silicone them and reassemble. I seal them on assembelly as they are famous for nuisance leaks.

 

[bobk]

That oil supply line looks scary too. Pull the cold side off and clean the mating surfaces then lightly silicone them and reassemble. I seal them on assembelly as they are famous for nuisance leaks.

Help me out here please. Until I got the Hatt, my experience was with a small Perkins and Lehman. I don't see an oil supply line in the photo. The line that looks collapsed is an electrical cable. Is this what you were refering to?

Bob

 

[Genesis]

There is an oil RETURN pipe off the bottom of the turbo. The supply line goes in the top.

 

[captddis]

Help me out here please. Until I got the Hatt, my experience was with a small Perkins and Lehman. I don't see an oil supply line in the photo. The line that looks collapsed is an electrical cable. Is this what you were refering to?

Bob

OK from what was visable it looked like the supply. sorry for the scare.

 

[SKYCHENEY]

I did have an oil supply line leak on one of my turbos (6v92). I just tightened it up and cleaned the whole mess up and it's been fine for about 3 years now. Mine was worse as you could smell the burnt oil after a run. That's not good, since it could easily start a fire if not corrected.

 

[bobk]

The oil supply and return lines on the turbo are tight and dry.

I checked the vacuum limiter and it has not tripped.

I pulled the breather hose from the AirSep housing and the pipe the hose connects to is dry on the front half, and wet with thick black oil on the back half. Didn't seem excessive though. But it hasn't been run the past three days. How does one recognize an oil pullover?

Other thoughts before I get a DD mechanic out to have a look and take my $$?? By the way, can anyone recommend a good mechanic near Port St. Lucie/Stuart FL?

Bob

 

[Genesis]

Look at the turbo blades on the intake side. If you're pulling it over they usually will be visibly oily/dirty where if you're leaking from the center housing into the intake they usually are not, since the oil comes from behind the wheel and doesn't get on the front part of the blades due to the airflow.

Also check the check valves on the return lines coming out of the airseps and make sure they are not stuck shut. If the coalesced oil cannot drain it will get aspirated.

 

[Brian Degulis]

Are you certain that's not coming from the exhaust? Sometimes a small leak is not noticed untill you do a lot of low RPM running. At low RPMs you will blow some oil out and it can end up reavealing a leak you didn't know about?

Brian

 

[bobk]

Karl, the check valve is working fine. I pulled the AirSep and found the intake blower fan is perfectly clean and dry. There was a little oil around the tapered part of the turbo housing

BUT, I pulled the blanket back a bit and found an oil seepage all around the area where the intake housing bolts up to the turbo body. This area on the inboard turbo of the starboard engine is completely dry. So I guess I have a problem that needs attention.

Is this a DYI job for an old man or should I just get a mechanic in? Who sells a good rebuilt turbo?

I'm still puzzled by the look of the splatters. They look like what you would expect if oil was put on a tooth brush and the bristles are flicked. Little tiny drops, and not in a pattern that you would expect from a leaking seal on a rotating shaft.

Thanks for all the guidance,
Bob

 

[captddis]

Karl, the check valve is working fine. I pulled the AirSep and found the intake blower fan is perfectly clean and dry. There was a little oil around the tapered part of the turbo housing

BUT, I pulled the blanket back a bit and found an oil seepage all around the area where the intake housing bolts up to the turbo body. This area on the inboard turbo of the starboard engine is completely dry. So I guess I have a problem that needs attention.

Is this a DYI job for an old man or should I just get a mechanic in? Who sells a good rebuilt turbo?

I'm still puzzled by the look of the splatters. They look like what you would expect if oil was put on a tooth brush and the bristles are flicked. Little tiny drops, and not in a pattern that you would expect from a leaking seal on a rotating shaft.

Thanks for all the guidance,
Bob

Read post 3 on page 1. It is an easy repair, no new turbo needed

 

[bobk]

Read post 3 on page 1. It is an easy repair, no new turbo needed

Capdis, The seepage I'm talking about is not from the oil drain pipe, but rather from the circular area that the intake housing bolts to. Are you suggesting dissasembling that portion and sealing it up? And if so, is there anything I need to be aware of so I don't screw up something, like bolt torque etc?

Bob

 

[REBrueckner]

" I'm still puzzled by the look of the splatters"
me too..it sounds like the seep you discovered under the blanket couldn't splatter outside the blanket....???

Likely nothing urgent...next time you go out can you have someone run the boat while you inspect with a light??? Or run the engine dockside at cruise RPM but in neutral....holding a piece of white paper here and there may help spot a small spray pattern.

 

[captddis]

That oil supply line looks scary too. Pull the cold side off and clean the mating surfaces then lightly silicone them and reassemble. I seal them on assembelly as they are famous for nuisance leaks.

i GIVE UP. Pull the air inlet side[COLD} OFF, CLEAN AND SILICONE THEN REINSTALL.

 

[Avenger]

If it's leaking from the compressor housing as captddis states the spatter is from the oil being driven out under manifold pressure. Running it up at the dock isn't going to prove anything since you develop zero boost under no load.

Just pull it off, silicone it and go boating. Obviously, when re-installing make sure the compressor wheel spins. Other than that it's a simple R & R.

 

[stormchaser]

Are you certain that's not coming from the exhaust? Sometimes a small leak is not noticed untill you do a lot of low RPM running. At low RPMs you will blow some oil out and it can end up reavealing a leak you didn't know about?

Brian

That's exactly the current situation on Saraswati...

 

[bobk]

DUUHHHhhh. Guys, thanks for your patience. I need to be reading the threads with my morning coffee rather than with the stronger libations of later in the day. Anyway, I now understand what to do with the turbo housing and will take care of it today, just need to get some RTV silicone.

Re the exhaust leak splatter possibility, that might be a little harder to identify since there was not a lot of it following a 140 hour run, unless it all happened in the last day or two. Anyway, I'll have a try at it while underway next time I get it away from the dock.

Again, thanks for all the ideas.

Bob
Chateau de Mer
1981 Series I 48 MY