I've had my 82 scrambler for about 22 years. Had the valve cover gasket leak fixed about the time I bought it while it was in the shop. When the cover was off then there was a pretty big buildup of junk then. Wasn't cleaned then. Fast forward to today. The valve cover gasket is leaking again and I'm going to ditch the factory plastic one and put a aluminum upgraded one as part of my punch list so my youngest daughter can drive it to high school. turns 16 in June.

Without pulling the head, valve springs, and stuff any tips besides brush and dry/wet vacuum. Thanks Hray

Find a car guy and install a V8. I just assume its a 258. While they do run forever, they never run well. I had an 83 and replacd it with a 360. I didn't really keep it long after thay, Maybe another 10 or 12 years. It did take me to Utah a few dozen times. Always better going over the mountains. And it sounded better to boot.

I'd be concerned about crud getting into the drain holes and then restricting the oil pump. Be very careful if you go that route.

On the other hand, maybe you could do a series of crankcase flushes with an oil change with each one.

I bought a CJ7 with the 258 in 2020. The leaking valve cover drove me crazy. I replaced it with an aluminum one.

To clean the junk out I would spray it with a mild degreaser and use shop towels to wipe up as much as I could. Then I would add half a court of oil just make sure there was some lubrication after using the degreaser. Probably best to do it right before an oil change.

When I swapped the valve cover gasket I had to drill and tap new holes in the cylinder head. Especially along the edges. Originally the valve cover was only held on in the front and rear and the holes on the sides were for indexing for posts. It wasn't hard but I was petrified since I had never drilled or tapped anything before. I screwed up one hole but I was able to us JB weld to make everything work.

The best way I found to make the gasket adhere and prevent any more oil leaks was to use a good cork gasket from felpro in combination with a spray on gasket adhesive from permatex. I sprayed the valve cover and the gasket first and let it set over night with the bolts through the holes so that the gasket set in the correct place. Then I sprayed the cylinder head and gasket and installed everything.

Be careful the torque settings are very low because it was originally plastic. It is only 28 in/lbs if I recall correctly. If you don't have the torque specs or a torque wrench in in/lbs I would get them finger tight plus half a turn.

New valve cover and if you are using a cork gasket, be sure you don't overtighten it.

Clean the surfaces well, a plastic scraper is best, you don't want to chip off any shavings with a metal scraper.

Some good cleaning, vac out and clean out schmutz.

Might want to run some SeaFoam High Mileage treatment or similar through it...

Sea foam in crankcase ? Says you can

Voice of experience here. Dropping the gunk through the oil return can quite easily plug the oil take up screen. This will stave the engine for oil. As will indiscriminate use of solvents.

Plug those returns with rags scrape out all the deposits and run a shop vac to get it all out. Sea Foam oil treatment following directions should be ok. I would think seriously about changing oil every 1000 miles adding the Sea Foam at about 900 miles. When the oil is draining clean you’ll know it’s gtg.

Again voice of experience watch that oil pressure. I had to drop the oil pan to get everything cleaned up once. Following my old man’s advice to fill the engine to overflowing with kerosene to soak for a week. Well it loosened up the crud, but all didn’t run out the drain. Maybe “you should have done it a few times”. Kerosene was expensive for a 16 year old saving for tires.

Thanks

If you are going to use any kind of chemical carbon cleaner, then removal of the oil pan is in order. You would think that the oil draining out of the pan would remove any loose debris, but it is not enough of a flow to do so. We use BG products at my shop, and they have a product called EPR that is an excellent carbon cutter, but it very clearly warns not so use it on badly carboned engines. We will do so, but the customer also pays to remove and clean out the oil pan. Sometimes it’s best to just leave that stuff alone and get what life out of it that you can.

While I might be tempted to wipe out what I could with the valve cover off. I would be very careful to not stir the gunk up to much.

I wouldn’t use anything to flush it or clean it out other then removing the oil from the sealing surface for gasket sealing.

If the engine has that much crud in it what little you remove won’t make that much difference anyway. The chances of what you loosen up and don’t remove stands to do more harm then good IMO.