magician0227

Got my son's 97 3.8L tore down to the block today in preparation for new head gaskets, and OMG I have never seen sludge like this!

The lifter valley is coated with a good 1/2+ inch of sludge. The car has 199k on it, and even for that high mileage, there was some obvious lack of maintenance in its prior lifetime.

In prior top end rebuilds, I have dealt with minor accumulations of gunk by just scraping the solids up while keeping a shop vac going while I scrape, then wiped up what was left with a little kerosene or diesel fuel. But I think this is going to require something a little more.

Unfortunately, a full rebuild just isn't possible right now. My budget for this car is pretty slim, so I am looking for the best options where "sweat equity" is all I can afford.

I am afraid to just scrape and wipe, as I do not see how I am going to keep the crud off the cam, and I am afraid with this much buildup, that I will just end up clogging the galleys.

So my thought was to scrape and wipe, then fill the block with diesel fuel, let soak, drain, drop the pan, and clean the pan and pickup. I will follow with several short duration oil changes with some ATF in the crankcase.

I have used this method to clean up older engines, but never a newer one. Would this still be OK to do, or does anyone have a better method?

Also, is there anything special I should be concerned with when cleaning up the upper and lower intakes, or is a good solvent soak OK?

Heads are going to the machine shop, so they will be professionally taken care of.

magician0227

Any help, opinions, or suggestions on this one at all?

petrock

If you have the heads off, then you should also have the push rods out. So I would just remove each lifter (keeping track of which wholes they came out of so you can put them back in the same place later) that way you don't need to worry about getting any gunk on the cams. Just hose the cam down with brake cleaner when your done. Before putting the lifters back in either pour a quart of oil over top all the cam lobes to lube it up again or coat them in assembly lube.

Keep in mind that if the lifter valley, chances are the oil pan is also well coated in sludge too. I would clean the lifter valley first, then pull the oil pan to clean it out and clean the pickup screen. That way any sludge that falls down through the channel in the lifter valley will fall into the oil pan, and you can clean it out afterwards... in other words, clean from the top down...

Good luck...