TKorrigan

I've got an 89 XJ all stock that I've had for almost two weeks now. I replaced the valve cover gasket yesterday and when I opened it up I was pretty disgusted by all the build up. I did a video on it so you can see what I'm talking about. My concern is, with the condition of this motor should I put all my money into my replacement motor rebuild right away or should I dump money into getting my suspension fixed so I don't feel like my *** end is swaying because of completely worn out leaf springs?

I've never seen flaky build up like this before on any other valve cover I've popped in the past so I am pretty concerned about it and need reassurance, thanks in advance!

Here is my video link:

TrailerTrash

I would do a compression test and see how that turns out. Does it have good oil pressure? Any sounds at all? does it actually run well? If there aren't really any problems that you can tell then I wouldnt worry about it.

I would have cleaned all that gunk off myself but i would not have used an air nozzle. You probably forced quite a bit of that junk down into the rest of the engine. You should have plugged all the holes with news paper or paper towels then started scraping/picking at it with a shop vac nozzle right beside the area to catch the particles you break loose. Then after all said and done give it an oil change.

TKorrigan

I'll get the compression test done as soon as I can and I'm not really sure if the oil pressure sensor works or not, it has been pinged out since I bought it almost two weeks ago. I ordered a new sensor today to see if that is maybe the issue. The engine actually sounds pretty good to me, it does seem a little sluggish, but gets up and goes if I really whomp on the pedal. Probably a better idea with the shop vac than how I did it, but too late now. I ran a half bottle of Sea Foam through the oil right before I did this and what came out of the oil pan after I changed the oil yesterday was some of the darkest oil I've even seen.

I figured I would do the Sea Foam treatment a couple more times to see if I can break all the crap free that is more than likely in the rest of the engine as well since it was up on top. Probably after the next one I will drop the oil pan to see what the engine looks like on the bottom side. I do have a 93 motor that I'm prepping to get moved into it so it just needs to last another month or so.

robertj

The last time I saw a mess like that was on a '69 Firebird. I promptly sent the heads off to be rebuilt. I didn't really want to mess with it.

TKorrigan

I hear ya man, I just need this engine to last another month and a half or so until I can get the 93 rebuilt to drop in.

BlueRidgeMark

No! No! No!

Don't do that. You are likely to break off some big chunks and block some passages.

If you want to fix the problem long term, just do oil changes every 500 miles until it's gently cleaned up. The idea is to clean it gradually so you don't break up the gunk and clog things.

If you just want to get by for a few weeks, dump some straight 30w, non detergent oil in there and hope for the best.

TKorrigan

Will that eventually clear all that crap out without adding any sort of cleaner? I've never ran into this before with previous engines so this chunky crap build up is all new to me.

dave1123

Short trips without getting up to temp is what causes the crap! My 4.0 has 233K miles on it and she gets run 3 to 4 days a week for at least 3 hours without being shut off, that's all year. 30 miles of each day is highway speeds and the rest is about 50 miles of stop&go at below 30 mph. I just did the timing chain and everything was just oily. Looking down the oil filler hole shows the same.

According to SAE, when the engine is shut off, the air inside contracts, pulling in damp cool air that condenses on engine parts. This moisture must be evaporated each time the engine runs or it forms sludge. I'm probably telling you stuff you already know.

BlueRidgeMark

Sure will. My engine was pretty bad when I got it, and within a year it was clean. When I did the head last year, I would say "spotless" was an accurate description.

I did add a quart of Rislone with every change, too, and I was running Rotella T6 or T4, depending on the time of year.

When I got it, I was commuting just over 50 miles, one way, so there was plenty of time to get it up to temp. Dave's right about those short trips - they are murder on an engine.

TKorrigan

Thanks a ton for this info, I did my oil change with T4 and will look into that Rislone you mentioned. My driving tends to be pretty long trips when I do get out since I live in the country so putting a few hundred on the engine happens pretty quickly.

Were you having overheating issues with your engine as well with all the crud in there? Mine seems to overheat if I spend much time over 60 mph right now, looking at doing an coolant flush, I haven't had the coolant tested, but it definitely isn't green anymore.

cruiser54

5 quarts T4 and a quart of Marvel Mystery Oil will work wonders. Change it in 1,000 miles and monitor the progress through the filler cap every 500 thereafter. It's gonna turn black fast. as long as when you take oil off the dipstick and squeeze it between your thumb and index finger, and it's slippery, you're safe.

Use a good oil filter like Wix.

kbeam418

Overheating at highway speeds is usually a water pump issue but I would definitely flush the cooling system if the coolant looks dirty. I would also change the oil every 1k or so to avoid the crud getting somewhere else plus the oil isn't going to be doing it's job as well. If you really want to get that crud out fast use a full synthetic.

TKorrigan

Thanks cruiser! I'm still working through your list of tips to get this old beast happy again.

cruiser54

You bet.

That "prescription" I posted is tried and true. I've brought a fair number of 4.0s back from the brink using it.

dave1123

The worst case of sludge I ever saw was a 62 Chrysler 300 convertible 413 cu. in. I bought. You know the old saw about the little old lady that just drove it to church on Sunday? I think this was the case! Long story short, it was so crapped up I had to use a scoop to clean the tappet chamber out! My Dad suggested I use Aeroshell aviation oil designed for radial engines. It's a high detergent ashless dispersant oil in 40W. We had it in drums at the airport where he worked. When I changed it the first time, it came out in CHUNKS! I changed it every 100 miles with a filter 5 times before it was clean!

Then I switched to Valvoline 10W-30 and the rest is history.