How to clean internal engine?

Recently got a 97 with 4.0 that looked like the oil hadn't been changed in several years and moisture had gotten into the crankcase. The is massive buildup on everyhing. I have pulled the head and taken it to be milled and dipped and dropped the pan to change the pump.
What can I use to breakup and remove all the gunk in the bottom end of the engine?

EasyOff Oven Cleaner.

old_man said:

EasyOff Oven Cleaner.

Click to expand...

Then rinse with what? Will it hurt seals or bearings?

I want to clarify, it's not baked on...just thick gunk on everything.

It sounded like you had the engine apart. Do not use it on an engine that is not disassembled.

The state of the engine is:
still in the vehicle
head removed
lifters removed
oil pan removed

The main amount of gunk is around where the lifters were, but the bottom end also has a considerable amount of buildup.

The crank and cam are still in place. It did not appear to be leaking so I am not planning to replace either front or rear seals.

Back before the dawn of time (early '60s...) my brother and I were resurecting vehicles from the late 20s thru the early 50s. Oils back then had a fair amount of parafin in them and sludge was the order of the day. Couple that with "bypass" filtration (as opposed to the flow through we have) and gunk removal was always the first thing on the agenda.

We used kerosene. We would drip the kero onto the head and flush the garbage down into the pan. With the drain plug out, most of the kero would drain. We would then pull the pan and scrape out the junk. The biggy is that the engine must have time for ALL of the fumes to clear prior to starting it. Hope you have a heated garage...

It worked for us, might work for you. Some brake cleaners (Autozone has an "environmentally friendly" one) work exceptionally well at breaking down grease.

In 67 I got a 52 Hudson Hornet (flat head 6) that had been setting, unstarted, since March of 53. When we pulled the drain plug, nothing came out. We could see it, it just would not move. That one we filled the engine full of kero and let it soak for two weeks before draining it. Another week with the drain plug and head removed to clear the vapors. New head gasket, rebuilt the carb. flush the fuel system and we drove it out.

I have flushed an engine clean in the past using a 50/50 mix of motor oil and marvel mystery oil. I did this with the engine intact. I would start it, run it for 20 min, drain-fill-repeat. It took several cycles to do this and a few oil fliters and a case of cheap oil and a couple of gallons of MMO.

This was a 85 Ford Escort so if it blew up I was doing the world a favor anyway LOL!

Not saying this is the way I would do this now but it did work back then and I put another 60k on the POS before I traded it off

If you have the time and resources, just pull the engine and clean it.

I have tried several rounds of both ATF and kerosene and it got a lot of buildup out of the engine, but the pickup on the oil pump was completely clogged, starving the top end causing lifter failure. Before doing any damage to the crank I pulled the pan.

I am working outdoors and would like to avoid pulling the engine.

My question is:

what can I put on the remaining buildup on the internal parts to breakup and clean them which will not do any damage to the seals or bearings.

Deisel fuel works best.

brakleen or acetone eats that stuff up really nicely. Just make sure you let it air out well and pump a couple quarts of clean oil through it before you try and run it.

You can buy acetone by the gallon in steel tins at home depot/lowe's. Check the paint prep aisle.

If you wanted you could even set up a sort of still to reuse the acetone... no need for heat, just leave it sitting for a while with a fume recovery / condensation system set up over it, and it will evaporate out of the bucket of waste leaving the sludge behind.

I am using carb cleaner to soften everything and a shop vac to remove it. I seems to be working well so far.

Since you have the pan off, why not change the main seals? It's pretty much right there.

The rear would not be too hard, but it wasn't leaking. The front would be much more difficult. I would have to pull the harmonic balancer, radiator, ac condenser, empty the freon......and the front main wasn't leaking either.

I suppose the short answer is why fix whats not broke.

IMO, if you plan on keeping it for a while, better to just replace them both right then and there than have to pull the pan again and replace them when they do leak. Just my 2 cents.

When you get ll of the gunk out that rear main will leak

I also would not mess with the main seals till they start leaking.

It's possible, even easy, to nick the new seals installing them and create a problem that wasn't there, or fail to fix the problem. Why go looking for trouble when it isn't there yet?