Logo

6V92ti with water in cylinder!

captainjojo

New member
Hi everyone,

new the the forum, just bought a 1989 Blackfin with 6V92ti's one engine has water in oil and water in air box! can anyone tell what the probable cause of this is?
 
Sad to say, the most likely cause would be the cylinder liner seals as they are positioned above the liner ports and would account for water getting into the air box. The liners themselves are also subject to a phenomenon known as "pitting" where small pinholes occur in the liner material adjacent to the water jacket. In either case repair would require that the engine be torn down.
 
Sad to say, the most likely cause would be the cylinder liner seals as they are positioned above the liner ports and would account for water getting into the air box. The liners themselves are also subject to a phenomenon known as "pitting" where small pinholes occur in the liner material adjacent to the water jacket. In either case repair would require that the engine be torn down.

Thanks for the info jgmo, was hoping for maybe just a blown head gasket.
These engines are 550hp and had 3500hrs on them two years ago, haven't been able to confirm the hrs from that time till now yet, but my guess is that their both due for an overhaul.

Does anyone know a good company to get these overhaul kits from? I guess cheapest isn't always bettest! and should I change the injectors or is it possible to get more hrs out of them?
 
Well, the liner seals are my best guess based on you saying water is coming from the air box drains. The only sure way to know would be to pressurize the cooling system and, even then, it can be difficult to discern.

You are correct that cheaper is not always better with rebuild parts and, since I have been out of the business for a few years now, I would have no recommendation as to the best source. I used to get all my parts from the big DDA dealer, Valley Detroit Diesel out here on the left coast. You might contact them if you are on the Pacific.

As far as replacing injectors during an overhaul, when you tally the total expenditure required to do a thorough and reliable rebuild, the injectors make up a fairly small portion of that outlay and I would not consider leaving the old ones in. However, these engines are somewhat modular in nature and I've seen people opt for less than complete parts replacement and still have success. So, it's whatever the budget and good judgement will bear.

Good luck.
 
Bought this boat with very little info, found out today that the motors had in fact been overhauled two years ago and have 980hrs on them, I guess the injectors should still be fine. Am doing all the mechanical work myself and will start by taking off the head from the side that had the water, also drained about three quarts of water from the sump.

Will post what i find.
 
Well, "overhaul" is such a relative term that some folks think you can buy one in a bottle and so, unless you know the guy that did it and his "honesty quotient" you'll never know what was really done or how well.

If, indeed, the liners and pistons were put in 1,000 hrs ago then there is no chance it could be liner pitting and I find it hard to believe that a head water seal would have failed in that time. These don't have "head gaskets" in the conventional sense. The heads are sealed with compression rings for each hole and water and oil formed sealing rings to contain the fluids. There is a head to block "perimeter" seal but it is less of a seal and more of a shim than anything else.

What happens with these when the block isn't properly measured prior to selecting the liner kits is that an undersized liner will be fitted and, because it is loose it will vibrate and move around destroying the liner to block seal in a hurry. I still think this is what you will discover and I would urge you to pressurize the cooling system to isolate which cylinder or cylinders are leaking. If the overhaul was done otherwise properly, you would only need to re-kit those cylinders with better fitting liners and that would save you a ton of money and time.
 
I live in the Bahamas so when you say a "overhaul" is such a relative term I have to agree with you 100% "Bush mechanics" are the norm here!

Will pressure test the cooling system first as you suggested, could the water have come from a cracked manifold via the exhaust valves?

Also found a lot of "gunk" in the air boxes which suggests that the last overhaul might have been done in a hurry.
 
Anything is possible but, again, water in the air box makes me think liners. Take your inspection covers (the ones you can get to in that engine room) off before the pressure test and make sure you have a VERY good inspection light and mirror handy. With the covers off, you can inspect the pistons and rings and probably get a good idea about how long ago those were replaced.
Hopefully, you can pinpoint the leak and get an efficient fix accomplished.
 
OK, finally got to my new old boat! its coolant leaking into #5 cylinder, engine still turns freely so left coolant level low and was able to start engine which ran fine, after stopping I again check air box which was dry.

A local bush mechanic told me to put some "Bar's" coolant stop leak in it then fill with coolant and see what happens, my guess is that you're gonna want to shout at me! "Don't be stupid" wat do think about this?

Also stb engine seems to have a bad injector, do you know a good way to find out which one it is?
 
Last edited:
Actually, I don't mind Bars Leaks at all. If it was good enough for almost the entire service life of the Nautilus, America's first nuclear submarine, then it should be ok to stick in an old Detroit. Problem is though, I predict it won't work. Or, if it does, it won't work for very long. But go ahead and give it a try and see what happens if you want to. If she stops leaking and you don't want to go offshore anytime soon then it might just allow you to use the boat while you save up for "The Big One".

If you mean that the stb engine has a dead cylinder and you think it's the injector, then yes, I know a good way to find it. I used to use a special little pry bar that I made that I could hook on the outer edge of the cylinder head to hold the injector down so that the rocker couldn't push on it.

Most guys just use a very large (at least 5/16") screwdriver and, with the engine running, hold it to the injector pallet and push down hard against the spring pressure for a couple of seconds. If the engine tempo changes then move on until you find the one that makes no difference. That's your bad cylinder and or injector.

This technique takes a bit of strength, quickness and some practice to do correctly. When you first contact the injector, with the rocker rapidly pushing and releasing it, the tip of the screwdriver tends to "dance" off of the top of the injector. Problems arise when it "ricochets" someplace you don't want it to. You can be injured or cause some damage if you aren't careful. I got to watch some real pros do it before I tried it and then I went on to make my little lever tools.

You might find a video of someone doing it on You Tube. Lord knows there"s just about everything known to man on that thing. The trick is to go "all in" when doing it, being totally committed to contacting the injector and pushing hard all in one swift motion.

Good luck if you decide to try it.
 
The "bar's" worked immediately! ran engine added Bar's, then 2 1/2 gallons of coolant. Once I find the bad injector on the other engine, n change oil n filters will take boat out for a run to see if this fix holds under full load.

Appreciate all the advice I'm getting here.
 
Update: just to prove how little I know about these engines, have just found out they are 6V92TA's not 6V92TI's! Port engine still not leaking coolant and running smooth. Found bad injector in starboard engine, replaced and the smoking has stopped.
This engine is now running OK but a little "clattary" so am about to attempt a "tune up", the ID tag I found on one on the rocker covers, under several layers of paint, say my engines are model #'s 80627403 and the injector timing is 1.508, the store that sold me the injector #145, which I was told was the same as the old injector #7045 (the same injector with different fuel line fittings, which can easily be switched) with a 1.460 timing tool and the manual I have says I need a 1.470 timing tool!
Can anyone here tell which one is the right tool to use and any hints on setting up the fuel racks? :confused:
 
Well, the AFTERCOOLER leaking would explain the water in the airbox and probably why the Bars Leaks worked so well. That might actually hold for a while.

Your eight digit number breaks down like this:
8...Series 92 V engine

06..# of cylinders

2...Marine

7...Right hand rotation (viewed from front of engine) with starter on the left and oil cooler on the right (viewed from the rear of engine)

4...Aftercooler equipped

03..This is the specific model number and would be used to determine injector size and turbocharger part number.

I haven't worked on any of these engines for a few years now and can't help you with the injector numbers. But, a competent parts supplier should be able to advise you. Not sure what resources you have available "out there" but it would definitely be worth a call to the mainland to make sure you have this stuff straight before continuing.

What is most important here, at least to me, is that you understand that all of the injectors MUST match or it will never run smoothly. So do all you can to verify that your replacement is correct before proceeding.

Have you checked valve adjustment yet? "Clattery" could mean anything from tight valves to oil starvation. I used to marvel at the noise a freshly rebuilt Detroit would make before it was completely run in.
 
I did a little searching for the cross from the 7045 (R-5227045) to 145 and found nothing. Also, detroitdieselmiami.com lists variations with letter designations H,P and T for the 7045.

Like I said, I've been out of the game for a while and these numbers are not familiar to me. The 7045 injector also comes up as a Series 60 injector as well.

You might want to give them a call and see if someone can tell you if you have a replacement that is applicable.
The number is 888-642-6460
Good luck.
 
As far as setting the fuel racks, it is a delicate procedure that has stymied many a first timer. Getting it "by the book" is, in my opinion, pretty much impossible the first time around. It will drive you absolutely mad. It took me quite a while to develop my technique and I'm sure I'd have trouble today since I've been working on electronic engines for so long and haven't seen a mechanical governor in years. You will have to settle for "close enough" unless you have that magic touch or weeks to fart around getting it perfect.

I will say that the closer you get the set up to the description in the book, the better the engine will run but most people can't tell a crappy tune up from a good one by listening to the engine.

Are you working with a book or any previous knowledge of how to go about the adjustments? I can walk you through it but we would need to get some terminology straight so that the communication is good.

Here's a concept for you. Try to get your head around this and tuning the engine will make more sense. At least it did for me.
OK, here goes:

These engines always want to run at idle. That's right, idle. If you were to start the engine with the valve covers off (something I used to do all the time using special cut away covers) so that you can observe the injector fuel racks, you would see that, with the engine stopped, when you placed the engine stop lever on the governor to the run position and the throttle control lever is at O% throttle (idle) the fuel racks will go immediately to "full fuel" or, all the way in. Then, when you crank the engine and it fires, the racks will immediately return to "idle" or move outward. That makes sense, right?

But, with the engine running, when you move the throttle lever to say, oh, 50% throttle, you would see the fuel racks move inward toward the full fuel position and then as the engine speeds up, they will move back out toward idle and pretty much stay there until the throttle setting OR THE LOAD is changed.

I emphasize THE LOAD because that's what these engines are all about. The only time the fuel control racks will stay all the way in for more than a second or two is if the engine is at full throttle and is FULLY LOADED. Under any other conditions, the racks will stay back toward the idle setting.

It's because the governor is always pushing on the racks to go to full fuel. The high speed spring exerts exerts that force. But, the governor weights, because they are spinning, overcome the spring pressure and return the racks to idle any time the engine is not FULLY LOADED. You can be running down the bay at 2200rpm but if you could see the fuel racks, they would be hovering closer to idle than to full fuel.

So, it can be said that:

The engine only adds fuel to increase rpm and overcome a load. But, when that rpm is reached and the load is being "moved", the rack returns to idle to MAINTAIN that rpm and KEEP the load moving. Nothing more. That's what it's all about. Adding just enough fuel to overcome the load and gain rpm but then backing off on the fuel and then just MAINTAINING that setting.

That's why it is so important to get all the cylinders doing their share of the work by having all the valves and injectors doing exactly the same thing so that they are "balanced".

Yes, the fuel rack adjustments are made in the full fuel position but getting them dead nuts even helps the engine idle better. This eliminates the governor weights from spinning unevenly, moving in and then out and "hunting" against the high speed spring due to a power imbalance between the cylinders.

I hope this helps and doesn't confuse you even more.
 
Great explanation.

I have no experience with these engines, downloaded a manual from "Boatdiesel.com".

Took the boat for a run today, seem to still have a problem with the port engine, runs very smooth at idle but is lacking power under load and when pushed smokes "black" with a lot of soot! The Blackfin 38 combi they are pushing wont get up on plane and max's out at 10.5kts at 1100rpm
 
Sorry for the wait, been REAL busy.

What you are describing with the port engine suggests maybe a couple of things. First and foremost, these seem to be symptoms of a turbocharger that is not supplying enough boost. The only, absolute, sure fire, way to tell is to use a boost pressure gauge to measure the pressures under load.

When you get a bunch of sooty, black smoke, that is PARTIALLY burned fuel. The engine is adding lots of fuel to get you moving but you aren't using (burning) it efficiently. That usually indicates a lack of air available but can sometimes mean that the engine is just plain old getting too much fuel.

What you describe makes me think not enough air. So, the turbo is high on the "usual suspects" list. But, I always check for intake and even exhaust restrictions before focusing in on the turbo. Collapsed or plugged air cleaners or plugged or kinked exhaust system can produce similar symptoms AND will keep the boost pressure low so those need to be eliminated as the cause before moving on the the turbo. A good visual inspection is usually all that is needed to find problems. If you are running air filters with restriction indicators, don't rely on the fact that they may be in the green. They are no substitute for human eyeballs and will sometimes hang up and give false readings.
 
Will do, I see there is a what looks like a air connection on the side of the air shut down unit on top of the blower which would give me the turbo boost pressure and my guess is that somewhere at the airbox inspection ports there is another, just need to track down some gauges.
What should the boost pressure be between the turbo/blower and in the air box's, also found the air box's to be very dirty, could this mean the aftercooler could be blocked?
 
The exact specified minimum boost pressure at full load would be hard to guess. It is normally rated using exhaust back pressure values and then charted using the engine's brake horsepower rating, turbo housing A/R, injector timing height and rpm. For example:

A 6V92TA turning 1800rpm loaded that has a turbo A/R of 1.23, 9F90 injectors at 1.520 timing and zero exhaust back pressure is expected to produce approximately 38.1n.hg (18.7psi)boost.

But with 3.0 in. hg EBP would produce around 33.8 inches mercury (16.60psi) in one of my service manuals.

A similar engine with different injectors and turbo and all else fairly equal might produce lower or higher boost running at the same rpm.

Even the fuel quality will skew boost.

So, it's sort of a guessing game based on several variables. But with what I just listed above, if your engine is only producing, say, 23 or 25 in hg (12.2psi) boost under those same conditions, then you know you are way off.

Just removing the intake pipe and looking at the compressor wheel and turning it to see how it rotates will tell you a lot.

CAUTION! Do NOT run the engine with the turbo compressor wheel exposed! If you've never screwed around with one of these, please understand that it can be VERY dangerous when powered up. Even at idle, the turbo can move enough air to suck anything "HANDY" into itself...including your HAND. And rags and towels and dirt and pebbles and...HAMMERS! Yes, they have sucked in hammers left nearby. Had I not worked on these using special covers with wire screen inlets on them, I would have lost my hand several times over in my career. It is a weird feeling when you get too close and it just takes your hand and slams it up against that screen. DON'T DO IT!

Your turbo will spin in excess of 100,000rpm. Yes, that's ONE HUNDRED THOUSAND rpm. Turbos MUST have a VERY RELIABLE source of clean, fresh oil to keep the shaft bearings from failing at such speeds. Most people that own turbocharged engines don't keep their oil serviced anywhere near as good as they should. That leads to problems fairly quickly. You may already be a victim of the previous owner's service practices.

As far as the aftercooler is concerned, it can't be completely plugged. If it were completely plugged, the engine wouldn't start. But, could it be dirty enough to affect performance? Maybe. They usually only get real dirty if the blower is leaking oil and coating the fins. Then, any incoming dirt tends to stack up. You would need to remove the turbo and the air inlet and screen to inspect the blower lobes for oil and dirt.
 
Thanks for the info jgmo, think I found the the problem. Tested the fuel flow from the return which was low, switched to starboard tank which shows full, flow immediately increased to the proper rate 0.9 gallons per hr @ 1800 rpm.
Untied the boat, idled out into deep water and run out of diesel!

Got to find out what was laying in the bottom of my STB tank and now know that gauge isn't working, guess the moral of this story is to carry spare filters, even if you're only going out for a quick test run.
Lucky a friend was close by and able to tow me back to my dock.

Here your back to, fancy a working holiday in the Bahamas?
 
Sounds like a case of algae to me. Might explain why the fuel gauge doesn't work. Working holiday? That's what my retirement turned into....HA HA!
Tomorrow I will be at a beautiful lake close to my home but will be watching all the people have fun while I try to make a buck.
Thanks for the update.
Here's to you getting her squared away.
 
Still haven't had enough time to get my port engine running correctly yet, need strip down it's fuel lines and clean or replace as needed. Before I do this I want to get the Stb tachometer sender working, anyone know where this is and is it driven by the alternator or a magnetic pickup?
 
Look on the rear of the blower. Traditionally the tachs are driven off of an adapter that connects to the left (from rear of engine) blower lobe. 90% of the tach problems are at that adapter. They can usually be replaced or repaired at any good speedo/tach shop.
 
Back
Top