How to check and repair Turbo Oiler

While working on problems starting the Port Engine, we dug into the bypass valves. While doing that it was suggested by the very wise JGMO that there is too much oil in the blower and that it could be coming from the turbo or from the blower seals. So I am starting a new thread, posting pictures of the bypass valve and blower showing the oil and a couple of external pictures of the turbo.

Need help with next steps, should I remove the air horn again and look towards the pre-cooler and see if there is oil in there? Would that prove it is the turbo and not the blower seals? Also not sure what I am looking for, since this is all new to me I would not have known that the oil in the blower was not normal.

The good news is I am learning a ton from all of this, the way I see it getting a good look at the turbo will help a ton.

I sure appreciate you all helping me

Crabber50

Here's a little something about turbos you WON'T find in the book. And...I don't know why! It is VERY important but they never emphasize this stuff. As if we are all BORN with the knowledge!

A turbo is EXTREMELY powerful. We always used turbo GUARDS placed over the inlet of the compressor wheel if we needed to run the engine with the inlet ducting off. The reason is not only to keep foreign objects like rags or tools from entering and damaging the turbo but, more importantly, to keep YOU out! I once reached for a hammer that I had left on top of the 6V92TA I was working on while the engine was IDLING. I picked up the hammer and started to bring my arm and hand back in front of the turbo intake. I never made it! The suction from the turbo grabbed my hand and slammed it, WITH the hammer still clenched in my fist, right up against that screen! Had that screen cover not been in place, it would have been a VERY bad day for me and I would be typing this missive ONE HANDED. I REPEAT...That's the power of a turbo at IDLE!

Until that happened, I never FULLY realized just how powerful the turbochargers are. I gained a whole new respect and understanding of just what it is they are capable of.

When you are in the throttle and turning the engine at up around 1800 rpm and making in the high 20's boost, the turbo wheels can be turning in excess of 100,000 rpm. Think about that! 100,000 rpm! What else do you know of that turns that fast? I can't think of very many right off the top of my head. And, it's because that is DAMN fast!

Now, think about that some more and look at the oil feed line in your #6 pic you uploaded. That line and what it should be carrying is ALL that keeps that turbo from flying apart at those speeds! Many people that own turbocharged engines are not aware that, because of the rpms these things do, that they REQUIRE cleaner...fresher oil than a normally aspirated engine. The turbo CANNOT survive on dirty, broken down oil. The lack of timely oil changes that an engine can easily withstand, will kill a turbo shaft bearing set pretty quickly. They HAVE TO HAVE a STEADY, CLEAN supply of top grade oil AT ALL TIMES. That means that that feed line in pic 6 is CRUCIAL.

And, we go to picture #5 and we see the bearing oil drain line. That needs to be kept clear so that oil can easily drain back from the bearing to the crankcase. I have seen them get clogged with pieces of gasket material... and silicone...and parts of shop rags. If that line clogs, the oil can't flow past the bearing as is desirable and will actually look like a loss of lube failure when analyzed.

As far a checking the turbo for passing oil at the compressor wheel, just refer to your picture #1. You just need to remove the blue silicone hose, held on with the spring tension clamp, at the turbo outlet. It's at the top of the photo. That should tell the story. It should be fairly clean and dry in there. Also, if you remove the inlet hose (marked W - R in the photo) you can gain access to the wheel and can see if there is too much lateral and axial play in the shaft. You can also gauge the amount of oil that may be getting past the seal that way and also inspect the compressor blades for any damage or for being bent. GO AHEAD! reach in and give her a spin with your fingers!...but.....

....Just remember...DO NOT RUN THE ENGINE WITH THE INLET DUCT REMOVED unless you use a protective screen. And, even then...you need to respect the power of this device when it is moving. IT CAN HURT YOU!

Turbos will also pass oil on the turbine side. As a matter of fact, the turbine wheel oil seal is MUCH more likely to fail than the compressor side seal. This is because the turbine side is where all the HEAT is! You can see your exhaust PYROMETER in the upper left corner of picture #1. It's important to monitor exhaust gas temperature on your engine and not allow it to operate at too high a reading for extended lengths of time. I don't know the specs for your set up but somewhere below 850 to 900 degrees Fahrenheit is usually a safe range. If you routinely see temps go beyond 900 degrees, then you may need to investigate.

jgmo, that is an amazing story and you are 100% correct that I had no idea the power the turbo has, it is actually quite frightening, seems there should be a warning sticker at least!

Will give the inside a look and post pictures back. Thanks for the info on the pyrometers, we have good gauges at the helm as well so will keep an eye on them. Notice the temps move up real fast when we run at 2000 or so RPMs but I do not think they exceed 750, but will start logging that so I get a better feel and will know if something changes.

Check heat exchanger zincs yesterday, they need to be changed, wondering if there are others that I need to find, on raw water pump? Next week oil change!

Crabber50,
I'm glad my little tale had an impact. Yes, they CAN be dangerous but LAWD, LAWD, LAWD...they are SO MUCH HELP! It FREE POWER! Without those things pumping air into your old in line 71's, your attainable hull speed wouldn't be anywhere NEAR what you have now.

But what I was REALLY trying to get across was how IMPORTANT the oil changes are. Fresh clean oil is what keeps them healthy and, if I was going to make a "sticker" I would be tempted to put that on them instead of DANGER.

But yes, of course, they can eat you for lunch and that's good to know too!

750 on your EGT sounds about right.

As far as zincs....your guess is as good as mine. The raw water pump sounds reasonable and I would be looking at the exhaust manifolds for some too.

Again, if it's a Johnson and Towers marinization they might have some useful data for you.

Previous owner changed oil annually and that was my plan as well unless I exceed 150 hours, sound about right for turbo life?

Several years ago I would have said that what you suggest was "adequate". But now, the oils have gotten so much better, with the advent of the newer API CJ ratings that combat shear and breakdown. I think that will be more than ok......IF.....

A year is a long time....much can happen in a year....and.....contamination becomes a possibility as soon as you pour the oil in the crankcase.

What am I talking about??? Water?....yes, maybe.

But much more likely and insidious is DIESEL FUEL.

One drooling injector can take out an engine as well as it's turbo in a year by "quietly" diluting the fuel.

Do yourself a favor and get an oil viscosity gauge. Use it to take quarterly (at least) oil samples and test for dilution to keep yourself safe. The gauges are easy to use and will flag a dilution problem well in advance of you noticing the engine "making oil". That is if you EVER notice a Detroit making oil because of their leaky nature.

You simply test the viscosity of the new oil at about 100 degrees F. and put it in your log. I put the gauge in my armpit for a time to accomplish that. You then get a middle of the sump sample with a suck pump and compare the viscosity of the oil (armpit temp) as it "ages". The Navy used to allow 6% dilution....I would NOT let it get that high.

Use the 40 wt. CJ4 oil (or latest API) and a vis gauge and you won't go wrong.

A little science never hurt anybody.

Finally got around to taking the turbo outlet duct off to look for oil, here is what was found. It seems like there is an oil leak? How severe would you rate this? This is the Port engine which seemed to have a stuck bypass valve and was hard to start, however seems to be running and starting well since.

JGMO,

"Do yourself a favor and get an oil viscosity gauge"

Where can I get one? Haven't had any luck finding one.

Hi Crabber...

Yep...just as I thought, it's not good in there. The oil seal for the compressor wheel is failing and the seal for the exhaust side is likely not far behind. It should be "DESERT DRY" inside that duct work.

Keep in mind that turbos are really SIMPLE devices....they are basically two multivane propellers on a single shaft inside of a metal housing. THAT'S IT. But, they are PRECISION BALANCED due to the high rpms they will turn. The shaft seals on yours need to be replaced. The seals are NOT expensive but it takes a special pair of snap ring pliers to get to them. If you can find a GOOD turbo shop that is interested in HELPING you and not GOUGING you, they can do it for a reasonable price.

But, most turbo shops don't want to just replace seals.....why there's no BIG money in THAT. They want to do a FULL MONTY "rebuild" every time they crack one open. And, that COULD be justified if there is any damage to the wheels or shaft. You have to take yours off and do an assessment yourself to be sure. Any chipping or evidence that the ends of the vanes are contacting the housing could be a sign of an out of balance condition.

Just remember...no matter what it ends up costing to get them repaired RIGHT, it is much less than having one fly apart. And yes....I did say THEM. If that one is losing seals then the one on the other engine is going to want some too pretty soon.

The link to the Louis C. Eitzen "VIS-GAGE" is below. It is the one I've used for over 35 years.


http://www.visgage.com/pocket.html

Good luck.