Replace turbos?

During the survey of my recently acquired boat, the mechanical surveyor said the turbos would need to be replaced. I have found oil on turbo housing only when running the engine above 2000 rpms. At trawler speeds, 1600 or so, ib get little oil on the housing. I do have Some oil in the air cleaner.

I know air cleaner should be dry, but am wondering if the problem could be more easily solved than rebuilding turbos.

Engines have 1200 hours and brought us to Hampton, Va from Miami without incident.

Thanks for any insights..

Gordon

Get a second, first-hand opinion from a professional someone with good references.

You bought the vessel anyway, knowing of a potential issue. Was the surveyor more explicit? Did you negotiate for price reduction to replace?

So moving forward, armed with year, make and model of engine and pictures provide more info. In the event the turbos are bad due to ingestion of salt water you could have a much bigger issue. Have you considered posting on boat diesel?

Sunchaser,

I am on boat diesel now and can't seem to find the button for a new post.

Yes I bought the boat anyway. Replacing turbos is no big deal, but I dont want to do it unnecessarily. Yes, I got the PO to discount price for turbos and new exhsust elbows.

No salt water ingestion. The only issue is oil leaking showing up on turbo housing. Engines are 330 hp cummins 6BTA5.9s.,. Mofel year 2003.

on the housing or inside the housing??? A pix would be nice.

The oil shows up in the intake side, to include the air cleaner, and on the turbo housing, between the intake and exhaust. Blades on both sides are tight.

I might be able to send pics later.

Turbos don't usually wear out, they corrode out from sea water. But I suppose an oil seal could be bad.


I am still confused about where you are seeing oil. If it is in the intake throat then it could be caused by blowby being sucked into the turbo inlet, particularly since you say that the air filter was oily.


Which engine? If it is a Cummins B then sbmar.com has a nice system called Envirovent that contains the blowby and its oil. It can be adapted to other engines. If you have Airseps on a Cummins B, then that may be the cause of your oil problems. Remove it and replace with an Envirovent or nothing.


Or you could just be slightly overfilled and the oil is whipped up and goes out and into the turbo inlet. Drop the oil level a quart and see what happens.


David

are you sure you don't have a blow by return system feeding oil into the filter?

Those engines don't like to be over full of oil and depending on install angle may actually run best with oil a little low.


My 6Cs used oil until it got 2 quarts low then oil consumption went way down.

I don't know about being over full. I am uncertain how to explain oil on housing. Imagine the housing for the intake and exhaust fans. Each has a housing. The oil on the outside is showing up in the area between the two fans.

Gordon

I am getting this on both turbos, which seems odd that birth would fail at same time. Could happen, but still odd.

Also, i am not getting enough oil that it is showing up on the dipstick. I am seeing no oil consumption, or smoke.

Gordon J said:

Also, i am not getting enough oil that it is showing up on the dipstick. I am seeing no oil consumption, or smoke.

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A couple of things:

Oil on the intake side of the turbo is usually not a major concern; recirc from the crankcase is generally the culprit.

If your oil levels are suspect, might your engine be burning the oil?

Agreed that an inspection be a diesel tech familiar with your engine is in order.

Yep, if blowby is vented into turbo as most are, some oil can ooze around compressor scroll and is a non-issue.

On a B-motor, the envirovent system is a big improvement over the factory blowby vent.

first off if its leaking oil excessively on the cold side. you have a potential overspeed situation(very bad things will fallow overspeed) if enough oil builds up or gets sprayed into the engine. personally and professionally i would not risk it. depending on the mfg you could send them out and have them rebuilt, replace the whole turbo or just replace the turbo cartridge(center section). if the hot and cold side housings are good i would look into replacing just the cartridge as it will probably be a lot cheaper than a whole turbo asy.

I can get the turbos rebuilt for $800. Not the world, but if the issue could be solved cheaper, i would be all over that.

To summarize: no observable oil consumption, no sea water ingress, no smoke, no wobbly/loose blades, no blowby vented to air cleaner, no suspect oil consumption, the boat was bought even though the surveyor said the turbos need to be replaced (comment made after he saw oil on turbo housong) and the PO discounted the offer price to pay for turbos and a few other things.

I am wondering if there is some specific source of oil other than turbo seals that v could be causing the issue.

Gordon

Without proper tests nobody can tell you if your turbo needs to be replaced...

Gordon J said:

Also, i am not getting enough oil that it is showing up on the dipstick. I am seeing no oil consumption, or smoke.

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?????? more info. you mean the stick shows no oil???

Turbos have oil connections on the top of the center housing and those seals do leak.

I am having a hard time understanding your descriptions.

What I was trying to say, and somewhat frustrated with typing on the iPad, is that someone on this string has jumped to the conclusion that the boat is using oil. There is no evidence of that on the dip stick. I never mentioned this in my original description of the problem. I am getting some oil on the turbo housing. Period.

I did not mention salt water intrusion. Made up by someone else. Reiziger gets it somewhat. But, taking the Turbo off to give to someone for testing is probably as expensive as just having it rebuilt, and in the end I will have gone through the work of removing Turbos.

I think it boils down to: I see no leaks on the outside, only evidence of a leak originating somewhere inside. I am getting an oil spray/spotting on the outside of the Turbo housing. I am also seeing oil inside the intake and inside the air filter.

So, what I am asking, I guess, is there anything else that would cause oil to appear on the Turbo housing, particularly after running the engine over 2000 rpms?

Bayview, you mention oil connections on the top center housing. Do the seals leak internally or externally? I do not have an external leak. Imagine dots of oil on the turbo housing beneath where the oil line connects, but, no evidence that the oil line is leaking... at least from the outside.

So really, my original description is still spot on. I can also guess as to what might need to be done. I was hoping to find someone who was experienced who might give me some other things to check, before sending turbos off for rebuild.

I am sorry if this is frustrating some of you, but really, we can stop reading things in to my situation and believe that I have accurately captured the symptoms.

Not enough loss of oil to register on the dip stick. My crank case holds about 3 gallons. The tablespoon or two of oil I might loose in a week are not enough to detect on a dipstick.

If I am going to take the Turbo in for testing, I will probably just have it rebuilt, considering the time and effort involved.

The only reason I am taking them off now is that I have sent the exhaust risers in for rebuild and thought it an opportune time, if in fact they need rebuilding.

And yes, the surveyor knew of the need to rebuild risers and yes I bought the boat anyway.

Gordon

Gordon:


You restated your problem, ok, so now listen to my restatement of diagnosis you need to make to find the cause:


As Ski noted earlier, most boat systems direct crankcase blowby back to the air intake. Usually it is not very oily, but three things can make it oily: bad rings, an overfilled crankcase and an AirSep system.


You can easily check for bad rings by putting your hand in front of the blowby tube while there is some load on the engine. You will feel heavy exhaust pulses. Or remove the filler cap and feel for pulses.


An overfilled crankcase can let the crankshaft whip the oil up and out the blowby vent. This is probably the most likely cause. Lower the oil level by a quart and see what happens.


Finally an AirSep system can overpressure the crankcase and force oil out with the blowby and then into the intake. They work fine on DD 2 strokes but especially on the Cummins B, they do not. That is why Seaboard Marine (Tony Athens' company) developed their Envirovent system for the Cummins B and C.


AirSeps were factory installed on some Bs and yours may have them. Read the following. It is detailed and tedious but it describes exactly what may be happening to your engines: EnviroVent CCV Kit 4BT & 6BT Series - Seaboard Marine


Check for these three problems before rebuilding your turbos. I'll bet it is one of them.


David

All,

Thanks for the article submitted by David. Now I understand some of the questions. I dont think I have a ccv system but will double check tomorrow. I would have thought that the surveyor would have recognized this fact, but who knows.


The oil is at the full Mark. I have associated turbo leakage with speed, but perhaps it is better associated with boat angle.

picture of turbo snot

Here is an earlier picture after a couple days of running to include some above 2000 rpm

And Gordon, don't forget your surveyor told you to replace the turbos. For reasons that as of yet are not quantified. Bound to be some odd speculation.

But you are right to raise the question. Now ask the Cummins crowd at boatdiesel.

That looks like an oil leak not a rebuild. It's also pretty black, do you have records of when it was changed last? I'm with the others in this, oil overfilled or wrong grade. I would change the oil (BOTH turbos so unlikely to fail at the same time) and clean up the mess and look for a bad oil line connection or some other issue that will let the oil out. Smoke would tell the tail but you have none so I'd guess an oil leak. Rebuild last resort.

Difficult to see on my phone but it doesn't look neglected...

Congratulations on the new boat.

I guess the pix is sideways if so it sure looks like a leak at that oval fitting the hose attaches to

Gordon J said:

No salt water ingestion. The only issue is oil leaking showing up on turbo housing. Engines are 330 hp cummins 6BTA5.9s.,. Mofel year 2003.

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We just purchased, last year, a Nordic Tug 2002 with the Cummins 330hp and have experienced oil leaking out of the air cleaner after running the engine at 2400 rpm for a few hours. What we were told by others is that NOTHING is wrong with the engine. With the slight angle that the engine sits you need to run your oil level on the low side. Last oil change we put in 3.5 gallons instead of the 3.8. The oil level is barely at the low mark and so far no more oil out of the air cleaner.

Wipe up the spittle from the turbos. Done.

The air scroll with snap ring does not form a perfect seal. Very common to have spittle in that area.

In other words, OIL is CHEAP, forgetaboutit.

While this is about your turbos, you mentioned that the exhaust risers are being rebuilt, probably replaced. I have Cummins 6bt engines and have replaced 20 year old risers. I have noted poorly designed risers on a number of Cummins, not likely Cummins doing but builder, seen quite a few OAs with this. In these installs, the raw water input into the riser is on the engine side of the riser and it should be on the exhaust side. Tony's site, Seaboard Marine, has a good article and pictures that show the problem (Designing a Marine Exhaust System - Seaboard Marine . My point is to make sure your new risers are properly designed or you will get salt water into the turbos and likely the engine.
http://www.sbmar.com/wp-content/uploads/2015/10/NS_Exhaust-System_17_300.jpg
The jpg file shows the result.

Bnoft,

Exactly how mine were built. I am having deangelos marine exhaust, in ft. Lauderdale, rebuild mine with the water inject on the muffler side instead of turbo side. Mine had not started to leak, but do not want to worry about when they will start. I am having them built with 316 stainless.

Gordon