buckwheat Posted March 9, 2017 Share Posted March 9, 2017 87 MJ with 4.0L engine and BA 10-5 tranny. Recently I took my MJ on a 1900 mile drive across the country. At about 950 miles I noticed it was running a little rough and had a slight knocking/ tapping sound at idle up to ~2500 rpm. I checked all fluids and topped everything off, including front and rear diff, transmission, transfer case, and engine oil. I also replaced the air filter because it had foamy, cream colored crap in it, basically soaking the entire thing. I am guessing it was extremely aerated oil and water. Drove it the 950 miles back home. The tapping/ knocking sound was about the same. Sometimes it wouldn't be there, and at times it would get a little louder. I had no real choice, so I kept driving. At about 1800 miles into the trip there was a snapping sound and the tapping/ knocking got a lot worse. I finished driving it home and parked it. To my knowledge it was not producing any smoke from the tailpipe at any point. I never saw any kind of cloud behind me as I was driving. Today I started looking at it. The brand new air filter has about 1/3 of the length soaked in oil, but not foamy and creamy like before, just plain oil. I drained the engine oil and if you look really close at it with the sunlight shining directly into it you can see a bunch of glimmers suspended in the oil. I also tested compression on all cylinders. Number 1 through number 5 all had ~ 125lbs (wrong unit of measure I am sure, ignore that), but cylinder 6 had 0lbs. Also the spark plug from cylinder 6 looked black and oily. The other spark plugs ranged from the perfect camel brown to sort of white/ lean mixture looking. Finally, I decided to remove the valve cover to get a look at the lifters and push rods. As soon as I removed the first valve cover bolt, coolant started pouring out. Several more of the VC bolts had fluid behind them as well. I didn't think the VC bolts went into the water jacket? All of this to ask for your opinions. What do you all think might be wrong, and where should I go from here? I was thinking to remove the oil pan and take a look at the crankshaft and bearings and the piston skirts. Anything else I need to do or look into? Link to comment Share on other sites More sharing options...
DirtyComanche Posted March 9, 2017 Share Posted March 9, 2017 I'd pull the head and oil pan at that point. See what's on the bottom of the oil pan. My guess is you'll find some obvious carnage relating to #6. Link to comment Share on other sites More sharing options...
buckwheat Posted March 10, 2017 Author Share Posted March 10, 2017 So I pulled all the bolts for the oil pan. Any advice on how to break it loose? That thing is STUCK to the bottom of the block. Link to comment Share on other sites More sharing options...
DirtyComanche Posted March 10, 2017 Share Posted March 10, 2017 Get a fine gasket scraper and pound it gently into the edge. A drywall putty knife will work too if it is stiff enough, many aren't. Or you can put a block of wood against the pan and go at it with a sledge (turn the block sideways to spread the load) but that's a bit more destructive. Link to comment Share on other sites More sharing options...
buckwheat Posted March 10, 2017 Author Share Posted March 10, 2017 Honestly my pan looks pretty rusty. Are there any good quality replacement pans that anyone knows about? Link to comment Share on other sites More sharing options...
75sv1 Posted March 10, 2017 Share Posted March 10, 2017 I'd probably use a latter model year. Also, probably use the latter years oil pan gasket. Link to comment Share on other sites More sharing options...
Gene Posted March 10, 2017 Share Posted March 10, 2017 Hi, About a year ago I got this oil pan (88 4.0) https://www.rockauto.com/en/moreinfo.php?pk=877970&cc=1181584&jsn=2 from Rock Auto. Fits well and seems to be decent quality. Gene Link to comment Share on other sites More sharing options...
Eagle Posted March 10, 2017 Share Posted March 10, 2017 No real advice, other than to tear it down and find out what broke. It sounds like you blew a piston. Link to comment Share on other sites More sharing options...
omega_rugal Posted March 13, 2017 Share Posted March 13, 2017 I also tested compression on all cylinders. Number 1 through number 5 all had ~ 125lbs (wrong unit of measure I am sure, ignore that), but cylinder 6 had 0lbs. Also the spark plug from cylinder 6 looked black and oily. it`s pretty obvious whats wrong with it, hope the damage is fixable... Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 13, 2017 Share Posted March 13, 2017 Probably too late now, but pull the head first. Link to comment Share on other sites More sharing options...
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