Visit our Popular Forums

Islander30Will · 21-09-2019, 05:27

Greetings,
Last night I fired up my Yanmar 2qm15 after replacing the mixing elbow. Lots of water was spraying out between the manifold and the flange that leads to the mixing elbow. (I do have the brand new copper gasket in place) After trying a bit of a tighten to the flange bolts I fired it up again, but still had leaks. I tried one more time but on my 3rd attempt the motor wouldn't fire up.
Now, I already realize I will have to remove the manifold and take it to get machined somehow as the threads are totally jacked up and I can't get it to tighten enough to seal.
*My concern now, and question is. How much damage can be caused by a little bit of water getting into the cylinder head? I don't think its hydrolock because it's still turning over, just not firing. I also checked the oil and it seemed clear for water.

Any advice and knowledge would be greatly appreciated.

**a64pilot** · 21-09-2019, 05:51

A lot of damage can be done, a lot.
I’d suggest if possible that you get a mechanic involved immediately, and if your competent enough to do so, to remove the injectors and put a liberal amount of oil into each cylinder and turn it over by hand,that will hopefully prevent any damage until a mechanic can get there and troubleshoot. Put lots of oil in, it will hurt nothing if some runs out of the injector hole when you turn it over by hand. Some may flow out of the valves but again no harm done. Trying of course to prevent any rust before it occurs.
I’d suspect somehow a defective / improper mixing elbow, but really can’t tell on the internet of course.
Normally I’d try to talk someone through the things to check etc, except I’m afraid you may be playing with Fire, and I’d hate to talk you into a new engine because following my advice you ended up with a bent rod or a stuck valve that get swallowed etc.

Islander30Will · 21-09-2019, 08:51

Thank you for the reply. If I don't feel comfortable taking the valves out of the cylinders, would it be recommended to empty the old oil, which actually is new, to flush it all out and then refill it?

Compass790 · 21-09-2019, 14:20

Quote:

Originally Posted by Islander30Will

Thank you for the reply. If I don't feel comfortable taking the valves out of the cylinders, would it be recommended to empty the old oil, which actually is new, to flush it all out and then refill it?

what A64pilot was suggesting is so that you get oil in the combustion chamber to prevent rusting.
An alternative method would be to spray WD40 or CRC 5-56 in the air intake whilst cranking the engine WITH THE DECOMPRESSION LEVERS engaged if you don't want to remove the injectors.
Shut off the seawater intake as well
If there is no sign of milkyness in the oil it should be ok but you must get on with doing what either opof us suggested,
Rust never sleeps & you dont want yr piston rings to seize in the grooves or the valve seats to rust.
BTW what do you think of your 2QM15?

dennismenace111 · 22-09-2019, 09:16

Quote:

Originally Posted by Compass790

what A64pilot was suggesting is so that you get oil in the combustion chamber to prevent rusting.
An alternative method would be to spray WD40 or CRC 5-56 in the air intake whilst cranking the engine WITH THE DECOMPRESSION LEVERS engaged if you don't want to remove the injectors.
Shut off the seawater intake as well
If there is no sign of milkyness in the oil it should be ok but you must get on with doing what either opof us suggested,
Rust never sleeps & you dont want yr piston rings to seize in the grooves or the valve seats to rust.
BTW what do you think of your 2QM15?

My guess is that right now hes not real happy with that 2Qm15...and probably swearing at it.

stormalong · 22-09-2019, 12:35

Let's backup for a second. There is no way that water should be anywhere near the the flange where the mixing elbow bolts to the exhaust manifold. The fact that it is leaking is secondary to the fact that there is water there. The mixing elbow should be directing the water away from the manifold. If you did have a good seal at that joint you would have had a problem with the engine that you would not know about until you had a MAJOR problem.

If you do not understand what I am saying you need a mechanic right now.