Well, there was a ridiculous amount of sludge on my heads and in the valley under intake. I'd just changed the oil so I didn't want to use a lot of liquid chemicals that would go down in the engine necessitating an oil change before even running.

Based on what another user is going through, seems I'm going to have to drop the pan and clean up down there, anyway. I've already drained the oil and I'm very glad I did; it would seem during our recent torrential rains quite a bit of water had gotten into the oil pan via intake/heads. I'm talking like a gallon. I really need a new whatever that rubber thing is that prevents water from the engine. Very glad I emptied it out. With that in mind, I'm thinking of cleaning it all up with diesel which I hear does great.

I've already removed the large bits so now it's very small "boogers" and residue. Unfortunately, at least one drain hole was completely covered in sludge. I worry there is likely sludge in the internal paths, as well, which is why I'm considering a full flush.

To finish the job up top, I figure I can just spray diesel on it, hit it with a nylon brush, and flush with more diesel. More importantly, it will get all of those areas too tight for me to get at with a brush, such as in between springs, etc. It should go into returns, into the pan, through the drain, and into a jug (to later be mixed with pramitol and used on some pesky plants along my fence; waste not, want not ).

However, since I will have to remove the pan to replace oil pump and pickup, I might entertain flushing the engine prior to doing so. Apparently, an old school method was to put a liter or two of diesel in instead of oil and run it *idle only* for 2-3 minutes. They would then drain everything out and repeat the process. Afterwards, change the filter and fill with oil as usual. My immediate thought was, "wow that's a dumb thing to do" but apparently many people have done it with success.

I don't want to do this AFTER changing the oil pump and pickup, in case the pickup should become clogged with stuff cleaned from the engine, etc. I want my new components to stay clean.

I figure the safest would be as follows:
- clean heads and intake valley with diesel/brush, let it all flush into pan and into a bucket
- reinstall valve covers, intake manifold, etc etc
- add oil, start and warm up engine
- drain oil, replace with .5 gallon of diesel
- start, run 2-3 minutes while watching oil pressure gauge
- drain, repeat
- drop pan, install new oil pump, intermediate rod, pickup, and gasket
- fill with oil, new filter
- run and watch oil pressure and look for new leaks
- if all good, drive and replace oil every few hundred miles at first, then every 1000 miles a few times, and then as usual afterwards

I'd be interested in any tips those of you who have done this before might have.

 

I have never run diesel in the oil pan and I never will. Too risky, I don't recommend it. I would keep doing what you are doing now, physically cleaning it up. Once you pull the pan and clean it up, put new oil in it and run it. The detergents in the new oil will clean up the rest.

I hope you guys doing this are going to come out alright, and at least have a engine that is useful to you. But having all this junk in the engine is not a good sign about the condition of the engine. I would expect some oil burning and some noises here and there.

 

I would fill up a engine with diesel fuel BUT DO NOT RUN IT!

I have done this before after a coolant leak and with engines sunk under water in boats. Let it sit a few hours then drain. Most crap will loosen up and hopefully come out of the drain plug.


As you said you had a gallon of water drained out, Better check for any hydrolocked cylinders before starting the engine! Hopefully no rust has started in the cylinders too.

After that "flush" job, use some cheap oil and filter, run the engine at idle till it's fully warmed up and then dump that oil and replace with new oil and filter of your preference.