Rebuilt motor smokes

[Vino the Dog]

Just started testing my rebuilt MD21A and would like some comments. It is a rebuilt motor that was installed in the boat 10 years ago and never left the dock (Previous owner died shortly after the install).

With no load, the motor puts out a lot of blue smoke and leaves an oil sheen on the water after running long enough to get up to 150 degrees. Temperature does not go much over 150. Oil pressure sits steady at 50 pounds at idle with increase up to 60 at 2800rpm. Exhaust spews a steady, heavy water stream.

This is the first time I have had it running for more than a few minutes and up to temperature. I understand the difference and general causes of black, white, and blue smoke, so NOT looking for repeat of those concepts. What I AM looking for is comments on two things and specifically addressing a rebuilt motor:

1. What is normal during a "break-in" period, and;
2. What can be expected when a rebuilt motor has been sitting for 10 years.

The motor starts easy, sounds fine, and appears to run great except for the smoke. I have not yet taken her out and run under power long enough to see if it clears up over working time.

Any thoughts on what may be normal and best practice to further examine and break in this motor?

[FlyingCloud1937]

Try this link,

It comes from one of the best Diesel Mechanics I have ever known.

Microcogen.info
the very best procedure i ever read was written up in detail in a mack diesel manual
since then i have come across the same procedure from other manufactures that relate a similar process

it goes like this

the engine is not allowed to run at idle speed and without some load for any length of time other than
what it takes to assure that there is proper oil pressure and no leaks, or other issues such as non rotating
tappets.

the engine is then brought up to it operating speed and a load of approx 25% of rated is applied to the engine,
the crankcase pressure is monitored via a manometer and you run the engine long enough to see the pressure
start to drop off, this illustrates that the rings are starting to seat under this amount of load. operate at this level
until both the crankcase pressure have dropped and stabilized and the coolant temp has come up to its designed level
and stabilized before moving to the next step.

you then apply 50% load and the crankcase pressure will again rise, you run the engine at that loading until the
pressure begins to reduce and stabilize at its lowest level,

then repeat at 75%, and do the same

then repeat at 100% and do the same

if at any increasing step the crankcase pressure does not reduce, but begins to rise, you must reduce the loading
to the former step and run it there until the pressure drops and stabilizes and then step back up and repeat.

each step might take 30 minutes of run time, depending on a variety of factors.

the basic idea is to get the the engine warmed up as soon as possible, get a load on it as soon as possible, and run the engine
at increasing loading in steps while monitoring crankcase pressure.

most folks won't go to all that trouble, so my suggestion is to run the engine for a half hour at each step, 1/4 load, half load, 3/4 load, and then
full load, and you will have done a pretty good job of breaking in the engine.

this also depends on the type and quality of engine, one that is made of cheap parts, might take longer to break in fully, but doing the process as described will probably get a pretty good job done.

if you go the route without a manometer, just keep an eye on the crankcase breather, if at any loading level you see a pronounced increase
in fumes being expelled, reduce the load and run it at that level for another half hour and then increase the load and try again.

probably more engines are messed up in breakin by allowing them to run cold and with no load for protracted lengths of time than those
that were loaded perhaps a bit too much trying to break them in too fast.

i broke in my changfa in about 2 hours of run time, by stepping through each load level in 15 minute steps, twice

since then it has never been allowed to run more than a couple minutes at no load, after which it hits full rated load for the duration
of the testing.

there are variations on this theme but generally just about anything is acceptable other than running cold at no load.

bob g

Also a further discussion here

Lloyd

Originally Posted by Vino the Dog

Just started testing my rebuilt MD21A and would like some comments. It is a rebuilt motor that was installed in the boat 10 years ago and never left the dock (Previous owner died shortly after the install).

With no load, the motor puts out a lot of blue smoke and leaves an oil sheen on the water after running long enough to get up to 150 degrees. Temperature does not go much over 150. Oil pressure sits steady at 50 pounds at idle with increase up to 60 at 2800rpm. Exhaust spews a steady, heavy water stream.

This is the first time I have had it running for more than a few minutes and up to temperature. I understand the difference and general causes of black, white, and blue smoke, so NOT looking for repeat of those concepts. What I AM looking for is comments on two things and specifically addressing a rebuilt motor:

1. What is normal during a "break-in" period, and;
2. What can be expected when a rebuilt motor has been sitting for 10 years.

The motor starts easy, sounds fine, and appears to run great except for the smoke. I have not yet taken her out and run under power long enough to see if it clears up over working time.

Any thoughts on what may be normal and best practice to further examine and break in this motor?

[44'cruisingcat]

Originally Posted by Vino the Dog

2. What can be expected when a rebuilt motor has been sitting for 10 years.

Depends on whether the motor was properly prepared to be left idle. Rusty bores and stuck rings are possibilities.

[DumnMad]

Lloyd, I think you are saying you cannot test properly when not under load.
i.e. Need boat well tied to the dock and test the motor in gear at good revs. - not idle.

[gjordan]

I am not an expert, but I think you will find most rebuilders tell you to run them at near full power for the first 10 or 15 hours , or until they stop smoking. See if Volvo recommended a break in oil for its original break in time, and if so, do it again. Maybe you should just follow the Volvo original break in procedure. I have never seen a break in that recommended 25% power at the beginning. It takes a lot of pressure to seat the rings against the cylinder walls for a proper break in. Dont idle anymore than you have to until the rings are seated. There is a lot of info on the internet about this, so you might want to research a little more. Good Luck. ____Grant.

[capt-couillon]

Breakin procedures in post #2 are spot on. Diesels of any flavor are not happy running under "no-load" conditions regardless of age or rpm. Can lead to carbon buildup, cylinder glazing, and "wet-stacking". If you need to warm up the engine, best to engage the prop and load it against the dock lines while you bring it up to temp.

Blue smoke (burning lube oil) and oil in the exhaust water are typical of oil ring leaks in both Diesel and gas engines. In older engines this is usually stuck, worn or broken oil rings or oil ring expanders. In a rebuilt engine it is usually the result of the rings not being "seated" do to the engine not having been run long enough (under the proper conditions). The resulting wear from a proper break in will mate the surfaces of the cylinder sleeve and oil ring to eliminate oil leakage into the combustion chamber.

"Break in oil" (low viscosity high detergent) accelerates this wear process between the internal parts of the engine. Not only rings, but rod and main bearings etc. Low viscosity also helps guarantee adequate lubrication between tight new parts eg:bearings. High detergent helps keep the mating surfaces clean and free of microscopic metal filings. Up the rate of oil/filter changes during the first 200 hrs of breaking in a rebuilt motor.

Bottom line, with no black smoke (fouled or worn injectors) and no white smoke (water in the combustion chamber) I would follow the break in outlined above and you should see the quantity of blue smoke reduce and eventually disappear.

[sailorchic34]

Generally a rebuilt engine should not smoke at all. Plus for the first 15 minutes it needs to run at idle so the rings seat in. For the first 50 hours ish do not use more then 70% throttle. After that run that puppy

IF the engine has sat for a long tine then the ring could have rusted to the walls. Also if the rings are installed upside down they will not seat properly.

One other thing it could be is the injector limiter set screw could be open too far which would cause engine smoking, but black smoke not blue. The injector limiter sets the maximum throw on the injector pump and basically limits how far the governor can open the pump. Too much and it WILL smoke. If that is the case, you adjust it in a 1/4 turn at a time till the smoke does away.

If you do have blue smoke, you have rings or a head gasket issue. Probably rings.

[Vino the Dog]

Thanks, guys! Exactly the information I was looking for. I have done a couple diesel rebuilds in the past (Detroit 6-71 & 4-53) and had good success in spite of not knowing proper break in procedures. This one, a Volvo-Penta MD21A (Peugeot), I did NOT rebuild, but came in the boat when I bought it. Don't know how long it was run after install, but was told previous owner ran it at the dock several times, but never took the boat out, then he died and the boat sat for 10 years.

I have had it started several times for just a few minutes a time to see that it ran. Then ran it the other day for a while at around 1,000 rpm (moderate blue smoke), then ran it up to around 1,800 (lots of blue smoke), then up to 2,800 rpm (a whole lot of blue smoke) - total run time around 1/2 hour, then shut it down.

Obviously, this was not the correct procedure, hopefully not enough run time to damage anything. Motor sounds great, but what does that mean? My plan was to get her out on the river and take a 1-2 hour trip under load, but decided to ask you guys first. I understand seating the rings, but did not know proper procedure.

I am not really ready to take the boat out yet, so would like to do what I can tied to the dock first, unless you folks who know better advise not to.

A couple more specific questions:

1. Don't know what oil is in it and would like to change out to the break-in oil you folks recommend. Have a pump to attach to the pump out tube (don't know what it is properly called), but requires oil to be up to temperature. How about running, prop engaged, tied to the dock, up to temperature (last run got to 150 and no higher NOT under load), then shut her down to change oil - at what load level/rpm, and for how long?

2. Where do I connect manometer and can you recommend what kind to get since I don't have one?

3. Can the 25%, 75%, 100% technique be done over several runs, or should it all be done at once?

Thank you folks and I know I owe someone a cold beer!

Steve VR
SV Mystique

[capt-couillon]

At this point, you are not going to exacerbate the existing problem.

Change the oil! You can warm it up at the dock as long as you have it in gear and run it against the dock lines. Low rpm will not bother the engine as long as it is under load. Probably will make the neighbors happier as well. Cautions against long idle periods for diesels are assuming you are idling at no-load. Engine runs too cool and can lead to problems. Any high quality 10w - 30w oil is suitable for break in in your situation.

I would not worry about the manometer to check for crankcase blow-by. If you want to check for blow-by of the compression rings (and it doesn't splash too much) you can just pull the oil fill cap while the engine is running and check for smoke rings.

You can spread the break in out, just make sure engine is up to operating temp before increasing rpm.

Like I said earlier, it could be you have a stuck oil ring (hopefully not an upside down one as SailorGirl suggested) There are some other "old school tricks" for seating and unsticking rings but I am loath to suggest them here (Your mileage may vary)

It should stop with some good run time, if not it's cheaper than AIS

[sy_gilana]

Only use mineral oil, not synthetic, for break in.

[Vino the Dog]

That was what I suspected/hoped you would say Capt-Couillon.

Now the plan is, run at dock in gear (around 800-1000 rpm?) until up to temp, letting it run long enough to see if temp goes over 150, then change oil.

Then finish getting my sonar working so I can get out of here and recruit a commercial fisherman friend who is off for a while for a second opinion + crew, and if he feels it is OK to drive, move the boat down river from Portland to Ilwaco, Washington, about 110 miles. By then, should have a much better idea what is going on.

Had to ponder "cheaper than AIS" but finally got it. Good one! Also answers another impending question. If it don't correct itself, will still probably be OK to get me to Mexico where I can at least afford to hire a helper if I have to pull it down.

Would love to know those risky "old school" tricks you know about, just to ponder. If you don't want to post them, you can send them directly to me through this contact link on my personal web page:
Contact me

[Celestialsailor]

I hope you changed the oil before you did any of this. I am another one for a mineral oil break-in...NOT SYNTHETIC. If it were me and it smoked bad, I would take it out on the water and run it 75% of max for 3 hours. Then change the oil again. Who knows what moisture damage is done to an engine that sits.

[sabray]

Go synthetic higher dollar. Dino oil is a extraction of oils. Synthetic is similar but chemists refine the property's. change the oil at the same rate. It's. small dollars for superior lubrication. Better high and low temperature viscosity. The bs over Dino oils is nuts. Both are modified extractions. Good top end synthetic has property's that Dino does not. I know castrol is great. A good Dino like Mobil one or am soil is better. My opinion. At near 800 hours with changes every 100 hrs my engine is top gun. Valves look like day one. No gumming in the top end. Blahhh blahhhh..

[gjordan]

Vino, since you have received completely conflicting advice on this thread, I will again suggest finding out what Volvo recommends. Give a marine Volvo dealer a call. Buy the overhaul manual, since you may be doing more work on the engine. Unfortunetly the upside down oil ring on an owner overhauled engine is not unheard of. One other possibility is bad valve guides, but sometimes that can be cured by putting rubber CUP seals over the valve stem, and slip them down over the guides. It is interesting that it is a Puegot based engine. That makes parts easier and cheaper than going to Volvo. Good luck with it. ____Grant.

[capt-couillon]

Well, before I totally besmirch my already tarnished reputation I have one more "safe" suggestion if in fact one or more cylinders have a stuck oil ring.

When you change the oil, add a qt of Rislone engine treatment in place of one qt of oil. Run your break-in a couple of times. Remember we want the engine hot (not overheated) and the preliminary wear to occur between the rings and the cylinder sleeve. It would really be best, to do the break-in at the dock, only because you are working at a stationary load rather than pushing the boat thru the water so we can make the engine work harder. Maybe at night during the middle of the week.

After a couple of trys, if she hasn't quit, change the oil again with another qt of Rislone. Go ahead and make your run down the river. After 25-30 hrs of engine time, change the oil again. Don't be afraid to work the engine hard. As long as the temps and pressures are within average, no problem.
If she still has not slowed down or quit smoking, it's a good chance the cylinders are glazed due to improper honing during the rebuild, or low load running by previous owner.

Go ahead and take it to Mexico... Take lots of oil, but the engine will run fine as long as she is hot. When you get there you can try the following just prior to pulling the engine, honing the bores and replacing the rings. (PITA but not very expensive).

DISCLAIMER
1. See definition of "Couillon" (Dat would be moi)
2. Do not try this at home. You could put your eye out.
3. Your mileage may vary
4. Last resort before tear-down
5. Ok, let the flames begin.

Get youself a can of dis stuff...

Best get it before you leave the States as its even getting difficult find here. If the local grocery don' have it try Ace Hardware. Nuttin' else, not Comet or Ajax or even the "new and improved" Bon-Ami. Nuttin but the old original formula works. (Also good for polishing fogged Plexiglas in those old port-lights).

Having procured the magic dust, proceed as follows.
1. Administer two (2) shots of rum to le Capitaine
2. Remove air cleaner from da motor
3. Warm her up and bring up to around 1800 rpm (under load)
4. Pour 1/2 teaspoon of Bon-Ami into palm of hand.
5. With engine running, administer Bon-Ami through air intake a small pinch at a time until smoke stops or your half teaspoon is gone.
6. Wait 5 min with engine running.
7. If no results repeat steps 4 and 5 ONCE!
8. Celebrate or finish rum bottle.

One way or the other, shut the engine down, and if you are not getting drunk cause the problem got worse, change the oil before you run the engine again. This is a last ditch, and is an extreme measure. In 40 years of working on diesels I have used it exactly 3 times, all on my own equipment. Twice on diesels and once on a Model-A. Worked all 3 times. Caterpillar actually had a part number for their Magic Powder back in the day, and GM had a tech bulletin out on the same procedure in the mid 60's

But then again I'm not too bright, me. It was the last step before a tear-down so what the heck? BTW, take a set of rings with you when you head south if she hasn't quit with the smoke before then. Not so easy to come by in the land of mañana (which actually does not mean "tomorrow", it just means "not today".

Good luck, and stay in touch...

Cap' Couillon