M25, running rough, white smoke, low oil pres. Then dying

[Tchiffriller]

Hello all, thank you very much for any advice I am stumped and cruising and trying to get this engine all sorted. I bought it in January from a trustworthy fellow who said he had rebuilt it all including new rings and pistons and used it flawlessly for a season and now I'm having trouble with it.

When I first dropped it in the boat it ran fine except leaked a bit of oil out of the head so torqued all head bolts to spec and decided I needed to put on a new head gasket but that it could wait till I got to the outer banks. As I was traveling I motored one long day where the engine did fine then the next morning the low oil pressure light came on and I assumed it had leaked oil and misjudged how much and accidentally put in about 1.5 quarts too much which it blew out the breather.

After this she will start and run fine in neutral (little hard to get started) then when you put her into gear she will want to die at idle but if you throttle up you can get her to run for about 20 minutes @ about 1500 rpm full throttle then the low oil pressure light will start to come on gradually at first and the engine will die, also there is a lot of smoke and a bit of oil coming out of breather

I then changed the head gasket and the symptoms are still the same with the exception that oil is no longer leaking from the rear of the head,

Any advice is greatly appreciated as this past week has just been constant stress about the engine as were planning on leaving in a week for the islands

Thanks! And I'll attach a pic of the smoke

[Braxton]

I am assuming the white smoke is from the exhaust, is that correct or is it coming out of the engine itself somewhere?

[Tchiffriller]

Yes, the exhaust, and some out of the crank case breather,

Here's a link to the exhaust photo http://forums.sailboatowners.com/index.php?attachments/image-jpg.127873/

[Braxton]

So a few more questions:

1) Are you pumping raw water ok? (I'm guessing you are but given the smoke out the exhaust I thought I should ask)
2) What is your coolant level at?   Are you having to top it off to keep it where it should be?
3) If you examine the oil from the dipstick, does it seem to have the appropriate viscosity?   Does it smell like diesel at all?
4) With the engine running, if you pull the dipstick does the little bit of oil that was coming out of the breather tube stop coming out?    Does it now start coming out of the dipstick tube?

[Tchiffriller]

Yes pumping water fine

Coolant level seems normal to when I just topped it off the other day, could have gone down some but that could just be from purging the air out

The oil dipstick seems to have risen as I changed the oil after the head replacement and it was just below full and now it's just above full

What do my symptoms sound like? Thanks

[Braxton]

So there is a lot of speculation in this :)

The low oil pressure and oil coming out of the breather tube would point to you having oil pooling up at the top of the engine in the oil gallery and not it not draining back down.   This could have a multitude of causes.  Two of the more obvious ones are that you could be getting severe blow by on a ring causing the engine compression to pressurize the oil pan and push oil upwards, or you could have a clogged drain out of the oil gallery.   The reason I asked about the oil being forced out of the breather tube and it changing to the dip stick tube is this would point to one or the other of these.   

So a few disclaimers:

1) if I misunderstood you about the oil still coming out of the breather tube then all this is moot.
2) I seem to diagnose oil pooling in the oil gallery all the time and I have never ever been right, not once, not even close :)   So i'm probably off base once again.

[KWKloeber]

Looks like steam .. sure it's smoke? Any antifreeze (sweet pungent) odor to it?

If you don't know already - careful about the level on the dipstick.  The stick can give a false reading (no or low oil) when pulled, and then reinserted it's ok.  So it's easy to think you need to add and then overfill.  It's because the oil level drops when running, and as it drains back down into the pan the air in the dipstick tube, for want of a better description, becomes pressurized with the rising oil level (which comes up above the stick hole in the pan) and the oil doesn't flow up into the tube and the air isn't released -- until the stick is pulled and the seal broken.

-kk

[Tchiffriller]

Ok so cylinder one, farthest from the flywheel, will not fire, swapped injectors and still nothing, any advice please? How should I proceed

[Braxton]

I would try doing a compression test on that cylinder.

[Ron Hill]

Beside a compression check, Loosen the nut on the injector of the non firing cylinder and see if it's getting any fuel seeping out.

a thought

[britinusa]

Ok so cylinder one, farthest from the flywheel, will not fire, swapped injectors and still nothing, any advice please? How should I proceed

Curious: Did you determine which was not 'fireing' by slackening the injector nut of each in turn till one didn't make a difference?

Paul

[Tchiffriller]

Yes, that is how I determined that cylinder one is not firing, also then swapped injectors and cylinder one was still not firing, I got a harbor freight compression tester today and will do that tomorrow and go from there,

Amazed that my possible use of ether on a total of around ten starts  or overfill of  oil running for twenty minutes when most of the oil blew out of crank case could have caused a drastic mechanical failure

[Braxton]

Something wrong in the rebuild?  That combined with the overfill may be the culprit.   But I think we're still in the realm of speculation until you test the compression.

[Tchiffriller]

Good point, I'll post back tomorrow after I run the compression test, I really appreciate all of you taking the time to help me, I am an amateur mechanic and all pros In the manteo North Carolina area are booked solid

So thanks fellas!

[Tchiffriller]

With engine warm it's was 290 360 360 and wet test 350 380 380 cylinders 1 2 and 3 respectively