Questions for the diesel guys

Status
Not open for further replies.
N

Nice N Easy

What a damn mess. Started the engine couple of weeks ago. It ran for a few seconds and quit. Had been running perfect, never a problem. Fuel filters thinks I, so I change the filters. The two primaries, a 30 micron with water separator, 12 micron and the small 2 micron on the engine. The 30 was fairly dirty, but the other two looked very clean. Installed new filters for all three. Bled the system at the high pressure pump. Cranked it over and got a little sputter but wouldn't run. Bled it again, and not even a promise. So I went the full monty, got some fresh fuel in a jerry can, jury rigged the fuel line, bled it up to the high pressure pump. Then cracked the lines at the injectors, opened the compression release and spun it over for about 30 seconds. This is the recommended method in the Yanmar manual. Closed the compression release, tightened up the injectors, and tried to crank it. No go. NADA So, thinking maybe I hadn't bled it enough, went through the entire process again. Spun the engine over with the compression release open, and injector lines loosened. This time after closing the compression release, and tightening the injector lines, it wouldn't turn over. Turned about half a revolution and hit something solid. First thought is that I have filled a cylinder with fuel, and have a hydraulic lock, so open the compression release, pull the fuel shutoff, and spin it over for another 30 seconds. This time I notice water coming from the engine bay. A little looking shows it is coming from the intake. THIS ISN'T GOOD And this is a pretty good amount of water. So, I open the compression release again, turn off the raw water intake, and spin her over some more. NO WATER My primary thought is that somehow it blew a head gasket My hope is that there is possibly something I haven't thought of. Anyone have any ideas of where this water could come from, other than a blown head gasket. Is it possible that it could get in from the mixing elbow. This thing pumps quite a bit of water, and spins about 400 RPM with the compression release open. Have to get into it pretty quick, as I don't want a cylinder full of brackish water to sit there and ruin more expensive parts and pieces. Oh yeah, it is a 3gm Yanmar, raw water cooled.
 
Jun 7, 2007
515
Hunter 320 Williamsburg
Mixing elbow

Could be nothing more serious than the mixing elbow is coked up after three to five years, a common Yanmar problem. Your water story suggests it simply isn't getting through the engine, which will shut it down promptly. By the way, don't try to clean the elbow, buy a new one for $150. Zoom.
 
Feb 26, 2004
98
Pearson 365 Ketch Memphis, TN
Did you shut off the fresh water intake?

As soon as you it realized it wasn't going to crank easily ... you did shut off the intake ... tell me you shut off the intake. Otherwise a column of cooling water quickly filled your exhaust loop and without a bubble of exhaust gas to "push" it over the top, it could easily slide back down through your valves during the "exhaust stroke" filling your cylinders and cause both your "lock" and your starting problems.
 
Jul 12, 2006
85
- - nc
I'm with Dave

If it does not crank right up, then you have to close the intake thru hull for the engine. Without the exhaust to "blow" the water out the exhaust, it will quickly fill. As you stated that little impeller can pump some water. Close the thru hull, get the water out and you will be back to just the original problem, which hopefully has been bleed out by now. Let us know how you make out.
 
May 18, 2004
259
J-boat 42 conn. river
one question?

you mentioned raw water cooled. how old is the engine? yanmar built these raw water cooled engines for a lot of years. if its old enough could be the common problem with the rw cooled engines. over time they rust away from the inside out. problems usually start in the head. if a pin hole develops it can let water sometimes to get into the cly. one symptom can be hard starting, then one day enough drops into a cly to cause other problems such as blown head gasket or piston problems. been there done that with a qm series engine. over 20 years and two heads later i converted it to fresh water cooling. S/V Que Pasa?
 
N

Nice N Easy

Brain Fade

Well, I must admit to some paranoia and of course brain fade. I saw that water and panic set in. All I can think is head gasket. Nope, I didn't shut off the raw water intake, and yeah it did fill the exhaust with water. Pulled the exhaust hose, drained the water, and it fired up. Running as always has. Thanks for the quick info. You guys may be full of it sometimes, but you are certainly full of knowledge.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
agree with Capn jim

Raw water entering the intake manifold from either a rusted through manifold or through a blown intake manifold gasket, crack in the head, or a blown head gasket. Could also be a rusted block but that is only an outside chance. When you pulled the injectors, did any of them look REAL clean? This is a sign of steam being produced in the combustion chamber and if you did not see it then the head gasket is probably OK. Pull the intake manifold and check the gasket for "water tracks". they look like worm tracks only in rust. Also check the manifold over closely for hairline cracks. If everything checks out take the manifold to a good repair shop and have the sucker magnifluxed. This will determine if there are any cracks in her. If everything checks out then the only things left are a blown head gasket or a crack in the head. A crack/rust in the block will not introduce water into the intake.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Or it could be that!

Glad to hear you got her going again. Fair winds and smooth revs
 
Feb 26, 2004
23,343
Catalina 34 224 Maple Bay, BC, Canada
Sometimes full of it???

Nah, ALWAYS. Glad you fixed it. Fair winds.
 
May 18, 2004
259
J-boat 42 conn. river
you still did'nt say how old it is!

if its more than ten years old you should consider converting it to fwc.a new head for a 2Qm15 is $1000.00 my quess is that for a 3 gm is a bit more. if it gets to the point of a non salvageble engine that a comp new engine for a repower would be ballpark 8 or 9 g's before you have it removed and repowered. a few hundred to convert it is money well spent. imho been there done that. S/V Que Pasa?
 

GuyT

.
May 8, 2007
406
Hunter 34 South Amboy, NJ
Capn Jim - what does S/V mean?

There have been several posts that I dont know the meaning of "text jargan". Your "S/V" I have no idea what it means. I understand Que Pase! There is one more that I see all the time that bugs the sh** out of me cause I dont know what it means - What is n/m or nm. Seems that the n/m gets used as a sign off like a salutation. Please help me cause not even my teanage kids know this.
 

Jim

.
May 21, 2007
775
Catalina 36 MK II NJ
Oh No, I hope not

but let me ask. When you crank the engine the raw water pump goes, right? If the engine doen't start the water will build up in the mixing elbow becuase it can't get pushed out by exhaust. You have to open a drain and let it drain out. If the mixing elbow fills completely it has to be emptied or water can back flow into the engine. I this this is a bad thing. I don't know if this is possible with a Yamar but there is a warning about this in my Univeral manual. I hope this didn't happen.... Jim
 
N

Norbert

Check this

Check the "o" ring on your fuel filler cap. If it is worn or deteriorated that is how water is getting in the fuel.
 

Ctskip

.
Sep 21, 2005
732
other 12 wet water
S/V means sailing vessel and

nm means no message Keep it up, Ctskip
 
Status
Not open for further replies.