Curious as to what everybody uses on engine sludge ? I tore into my engine to replace a worn timing chain and discovered sludge around and behind the timing chain and down in the engine oil pan. I was reading about engine flushing but not sure if it's good on the old engines ? Mine is a 78 302, any ideas or suggestions would help. Pic is after I cleaned it up a bit.

 

Any good solvent will do the trick. Wd40, diesel, gasoline, and power purple or equal cleaner. Lots of elbow grease is going to be needed. If you have the means a hot tanking at your local machine shop will be your most efficient way of cleaning the old girl out.

 

Man that's gunked up! If it were my truck, I would yank the valve covers and possibly the intake to check out the rest of the engine. If the rest of the engine looks like that.. you are probably time ahead to pull the engine to freshen it up a bit. I can see from your picture that there is rust in the water inlet. Did it sit for a while?

 

Looks like a penzoil motor.
Same way my motor looked when I yanked it.

 

I was just about to say that! The problem with breaking all that free is it will travel through your oil pick up and to your bearings....not a good thing. Your absolute best way of getting rid of the sludge is a complete tear down and hot tank,new rings & bearings...an overhaul basically....but depends on your time and money.

 

Not sure on the history, nor time it sat and I pulled the valve covers and it looks relatively clean. Runs good, so before I yank it and rebuild it was trying to just clean it up and drive it till next year.

 

Even with Pennzoil, if it in fact is that bad, that engine has had extreme oil change intervals to get that gunked up. That and maybe a non-op PCV system. You had to be a real cheapo and go out of your way to buy and use non-detergent oil in '78.

 

Try using some ATF in your oil next oil change. Put in a quart,let it idle hot for about 10-20 minutes and drain. Use cheap($ not quality) oil...like Walmarts brand and change the oil 4-5 times over the next month. Use good filters though. and after that,change your oil once a month with the walmart brand and a good filter until you decide to pull the engine to re-fresh.

 

Going to pull the oil pan and oil pump, clean them both and possible replace the oil pump can I pour anything down thru the heads while the pan is off to help clean it out ?

 

I was going to suggest this. An alternative is diesel oil. Like ATF, it has excellent detergent qualities, but if your gaskets are bad be prepared for leaks. I have a feel that the only thing sealing your engine is all the sludge.

 

If you are going to remove the pan and pump, just flush the thing with diesel fuel..DONT START IT WITH DIESEL IN THE ENGINE! Also dont rotate pump(prime) with the diesel in there. You do not want to send the dislodged chunks of sludge into the bearings. Are you taking off the intake? You will be surprised at what you find there!...may make you reconsider the wait on overhauling the engine!

 

The old timers would replace one quart of oil out of five in the crankcase with kerosene and let it idle (don't drive it!) for a half hour and then drain everything. This would work if you just want to drive it for a while.

 

The back of my head around the number 4 hole looked like that when i took off the valve cover but nothing like that in the timing chain. I would take that thing down further to clean it.

 

Breaking all that sludge loose at one time is asking for trouble. I've had good results adding a pint of Marvel Mystery oil with each oil change, breaking it up slowly. Some swear ATF will do the same. The cleanest engines I've torn down were running Valvoline, worse was Quaker State. Valvoline will clean one up, but takes a while longer.

 

Thanks to all for the good info, and I'd rebuild it or replace it if I had the funds but that'll have to wait till next winter. Ok lots to think about, but I think I'll tear it down a little more and clean it up then run a cleaner threw oil changes and filter changes until it cleans up. I'll post another pick of the heads and under the intake manifold when I get there.