3GM30F Antifreze out of Injector Chamber

[Berk]

Hi everyone,
I hope you'll be able to give me some ideas about my situation.

Winterized the engine as usual in November and left the boat on hard at the marina. Everything was working fine during the season and haulout. The engine never touched or turned on since November.
Before the launch of this season, I wanted to have the injectors cleaned professionally. The disassembly was uneventful and everything came out easily. While moving parts around some small particles went into the injector chamber so I wanted to vacuum everything to keep it clean. To my surprise, some antifreeze came out from the first chamber while vacuuming. I don't think this is normal. Some suggested that the exhaust valve is open and I sucked antifreeze from the exhaust system.

Sequence of the whole situation:
1. turned the engine via the crankshaft to use the pressure to pop the injectors
2. Injectors removed
3. particles went into the chamber
4. used the vacuum to clean out.
5. The engine never turned on.

What do you think could fix the situation? Can I rotate the engine a bit more to close the valve and suck the remaining antifreeze?

 

[kloudie1]

Looks like pink antifreeze so it probably happened during winterization.. Pull the decompression levers, pull off the exhaust hose and the small water hose at the exhaust elbow .. Turn the engine over by hand two revolutions then spin it with the starter about 10 seconds and let the antifreeze clear the engine .. Drain the exhaust hose and muffler then re-assemble leaving the small water hose off the elbow..Turn the compression levers back ON.. The engine should start.. then shut it off and it should be OK to go once back in the water.

 

[Claude L.-Auger]

Having had to take care of a water lock, I concur with Kloudie. Plus I would do this to be entirely on the side of safety for your engine: You may still have some of that antifreeze in the passages and you certainly do not want to run any water in the engine when you get it started. So, while on the ground, disconnect you intake impeller hose and connect a hose that you will be able to draw water from a full bucket of water. Do not put the hose in the bucket of water yet. Remove your air cannister and spray some fogging oil in it (or WD-40) while turning the engine with starter as per Kloudie's. The fogging oil will help pushing the antifreeze out while lubricating the cylinder walls. Once engine has run decompressed for the 10 seconds, shut evrything off and reassemble exhaust hose. With the compression levers back on, get engine started and let it run dry for 10 or 15 seconds then put the hose in the bucketful of water. The impeller will start pulling water immediately. At that point, that water going through will push the antifreeze out of the exhaust system. Have someone collect it under the boat at the exhaust outlet so you don't pollute. Once you have clear water coming out of the exhaust, you can shut it off. Reinstall the impeller hose. And you'll be sure that it'll start and run OK when you launch the boat. Good luck

 

[Berk]

Thank you both - great tips

one small follow-up question

The injectors are with the shop and getting rebuilt. I showed them the rear chambers and they advised me to replace the heat isolators & copper crush gaskets.
The problem is they are so stuck, that they became one solid piece.

Can I separate them from the rear chamber or do I need to buy rear chambers as well?
What would you do?

 

[Charles Erwin]

If the raw system was filled with anti freeze, it is possible to suck it back from the waterlock into the combustion chamber. Just make sure it is winterizing antifreeze - not your permanent coolant.

As to the 'chambers' your photo shows 2, but there should be one for each of the three cylinders. The chamber is actually in two parts per cylinder. Your photo shows the upper part. They are one piece, they do not separate. The lower part is not likely to come free from the bore. Anyway, take these uppers to the Yanmar dealer and they will provide gaskets for both sides of those parts. The parts themselves are completely reuseable, once you clean the old gasket material from the surfaces, thus the new gaskets recommendation. Oh - be sure to use the O ring at the top of the injector stack so as to keep moisture out of the injector bores. One last tip - coat the injector bore lightly with anti seize when you re-install the injectors and the upper chamber. I use the Nickel formula - or ask the injector servicer what they recommend.