UPDATE to Seized 2QM15

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garylinger

garylinger

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May 2, 2008
254
S2 9.2C 1980 St. Leonard (Chesapeake Bay), MD
I just pulled the head and found rust in the combustion chamber (opening for injector and the valves) in the cylinder closest to the crank (away from the tranny). Also the water jacket openings in that area are clogged. I'm going to soak everything and hopefully free up the piston and remove the rust on the head. Assuming there is no permanent damage, I need to clean out the water jacket. Does anyone know of a suitable way to do that without removing the engine and boiling it?
 
T

tommays

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Oct 2, 2006
1,517
Jboat J24 commack
I would just be cautious as you may do more damage by trying to avoid taking apart the motor when it had enough rust to seize up

Even if you get it turning over its had to say if the pistons rings are stuck or damaged from the rust
 
BobM

BobM

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Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
Gary,

Did you take a hard look at the head gasket. Bet you that is your culprit.

With regards to the water jacket, most people run dilute acid through it to clean it, but you will need to rod out the passages to get flow first.
 
RichH

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
garylinger said:
I just pulled the head and found rust in the combustion chamber (opening for injector and the valves) in the cylinder closest to the crank (away from the tranny). Also the water jacket openings in that area are clogged. I'm going to soak everything and hopefully free up the piston and remove the rust on the head. Assuming there is no permanent damage, I need to clean out the water jacket. Does anyone know of a suitable way to do that without removing the engine and boiling it?
Click to expand
Best way to 'de-salt' the engine is to put in RydLyme into the fresh and raw water cooling loops. .... for a flush of the raw water side, just extend the inlet into the same outlet into a bucket and 'recirculate'. - Rydlyme is an inhibited acidic solution that only attacks/dissolves the carbonates and NOT the base metal of the engine. www.rydlyme.com/ DO NOT use muriatic (hydrochloric) acid as it will also remove engine base metal.

Once you get the head back on then pump in the Rydlyme. Or you can take the head to a 'radiator shop' that does ultrasonic cleaning, clean out the head passages with ultrasonic cleaning, then reassemble and do the whole engine and exhaust manifold with Rydlyme.

Make sure that you can identify if and where the head gasket was leaking .... if you cant, suspect that physical altitude of the eshaust exit to the wet muffler is TOO LOW ... and if so then consider to install a 'dry stack' on the exhaust to prevent 'suck back' from the wet muffler. If/when you find a rusted exhaust valve (or rusted exhaust valve stem) - consider that to be symptomatic of a fairly strong possibility that the engine 'sucked - back' water from the wet muffler. Do you have a siphon break on the water injection loop???? if not consider install one.
A 'dry stack' should elevate the physical 'highest' place in the exhaust system (that portion of the exhaust system that is 'upstream' of the wet muffler.

To get this engine turning .... consider to follow the outline previously posted of using MMO in the cylinders .... so you dont break the piston rings. This 'MMO soak' will work even with the head removed.
 
garylinger

garylinger

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May 2, 2008
254
S2 9.2C 1980 St. Leonard (Chesapeake Bay), MD
I have been trying to be patient and not cause any additional damage. This morning while trying to remove the stuck injector I noticed a "Y" shaped crack in the head from the exhaust valve to the precombustion chamber to the intake valve. That would explain everything. Now I need to explore my options. I still have not freed up the piston. As I see it my possible options are 1) replace the head (assuming I can free up the stuck piston). 2) rebuild the current engine, or 3) repower with a different engine. Options 2 and 3 would require removing the engine from the boat. Does anyone have any experience with engine removal from the S2 9.2C (center cockpit). I'm not sure what would need to be dismantled or even if it could be without actually cutting away portions of the boat. Any USEFUL suggestions???
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,353
Catalina 34 224 Maple Bay, BC, Canada
Bill Roosa

Bill Roosa

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Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
How is access to the underside?

IF, and a major IF you can get the oil pan off you may be able to save the engine. Hang up saving the piston and rings. They are goners. Rust on the cylinder REQUIRES a re-honing. You can't do that with the piston still in the cylinder. If you can get the connecting rod disconnected on the crank end you might be able to BEAT the piston out by (gasp and hold on to your shorts) drilling a hole in the piston head and using an auto body dent puller or equivalent to get the piston out. Then all you need to do is hone the cylinder, buy a new piston and rings and reinstall (gasp again) from the top. I have done top installs of pistons but it is not easy. A ring compressor is handy BTW. Cost is pretty reasonable compared to a new engine.
A cracked head can be welded and a thorough cleaning of the water passages is in order. DO NOT get your cleaning fluid in the cylinders as it will find its way to the bearings/rings and etch them. Failure of etched bearings is pretty much a sure thing, just a matter of time. For that matter rust needs to be kept out of the cylinders too. Keeping things clean is VERY IMPORTANT with bearings and rings.
Consider the following: if you can drop the oil pan and then the crank shaft you can take out all the innards and do a thorough cleaning.

What is your labor worth? A new engine may be more money and less work.
 
garylinger

garylinger

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May 2, 2008
254
S2 9.2C 1980 St. Leonard (Chesapeake Bay), MD
Re: How is access to the underside?

Bill, I don't think I would even have enough room to get the oil pan off. I was not aware that the head could be welded. Do you know of any decent mechanics in your area. I'm just down the road and bay from you.

Gary
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,353
Catalina 34 224 Maple Bay, BC, Canada
RichH

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
garylinger said:
Bill, I don't think I would even have enough room to get the oil pan off. I was not aware that the head could be welded. Do you know of any decent mechanics in your area. I'm just down the road and bay from you.

Gary
Click to expand
THE Yanmar source for you area is still Bayshore Marine services in Annapolis - just up the street from the "West Marine'.

Cast Iron is very very difficult to weld, most will BRAZE it for repair but such is not a 'long term' repair vs. internal corrosion but can be done. Yanmar heads are cheap in comparison to a second go-around with a cracked and leaky head. Call Bayshore and see if they dont have a used / second-hand head for your 2QM laying around.
 
garylinger

garylinger

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May 2, 2008
254
S2 9.2C 1980 St. Leonard (Chesapeake Bay), MD
I pulled the starter this morning and used a small crowbar to turn the flywheel. With a little effort I finally got it to turn but there are still a couple of spots where it is tight. I'm not yet able to turn it completely with the crank so letting it soak some more (pistons in opposite positions that they were when it was seized). The cylinder sleeve walls did not look scored. If I get it moving as freely as it should and if there aren't any other apparent problems, I will tackle the issue of the head.
 
Dan Johnson

Dan Johnson

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Oct 14, 2005
2,191
1983 Hunter H34 North East, MD
Gary...

as an old engine builder, I'd want to drop the pan and look at all the bearings too. Freeing up an engine that has been rust frozen is not very kind to the rings either. I think I'd pull the pistons and look at the both bearings and rings mentioned above, then take a look at the main bearings. If you don't have a shop manual, now's the time to get one.

PS: Should have read Bill Roosa's post more carefully--he's dead on about what I just said.
 
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