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Rough idle, blowing oil out dipstick at speed

sirreal

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Amarillo
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98 Explorer V8 EB
Happened to me while pulling 1000 lb trailer hard uphill. GF behind me notices white smoke coming out from under the truck and calls me to tell me I'm on fire. Not, but after pulling over, I did notice that the oil dipstick had pushed up 9 inches and the driver side under the hood was covered in oil which had dripped down onto exhaust manifolds.

All gauges read okay so I limp back into town and park it for a week. No oil dripping after that but I've got a rough idle and smell oil burning.

Research tells me to change oil and replace PCV. Done. Still idling rough and still smelling of burned oil. Dipstick was pushed up 2 inches today after light drive down the interstate.

1998 Explorer 5.0 EB, 169,000 or so miles. Great condition beyond that.

I think I next need to have a compression test done to determine if a cylinder(s) are leaking. I'll have plug wires and plugs replaced then.

If pressure is good, do I find a way to better ventilate the head gasket? If pressure is bad on one cylinder, do I replace only the rings on said cylinder? What about replacing ALL pistons/rings with "improved" versions?

What would you "quite smarter than me" types say to all this?
 
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my98nnj

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Excessive blow by due to failed rings.
 
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rb142

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Yeah. If you have pressure in the crankcase pushing the dipstick up, it's likely blow by from bad rings. You definitely need to start with a compression test (dry and wet). You could also do a leakdown test -- put air pressure into the cylinder and check for it leaking out at the dipstick or oil filler cap.

If the rings are bad, you are probably looking at a new engine or rebuilding this one ... including machining the block. You can't just throw new rings on it if there is also wear to the cylinder bore.
 
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sirreal

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I know it depends; but rough estimate on the rebuild for maybe just one cylinder?
 
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koda2000

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Excessive blow by due to failed rings.

very likely this... but you might as well check/replace you PCV valve and the hoses, grommet attached to it. if you don't have positive crankcase ventilation you might be building excessive pressure.

i don't believe rebuilding just one cylinder is realistic. besides, if one is worn they'll all be worn.
 
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sirreal

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New (used) engine with 80k fewer miles for $650, installed with some new parts for total of $1500. Runs like a dream now.
 
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bluestream1

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Could be a cracked piston as well. Not likely worth fixing.
 
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Flash

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New (used) engine with 80k fewer miles for $650, installed with some new parts for total of $1500. Runs like a dream now.

I always like to do a post mortem on an engine when something like that happens.
It's entirely possible that bad fuel was causing detonation which cracked your rings and or pistons.

It would be good to know that so you could avoid doing it again.
 
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1992fordgreen

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Inside the Rehabilitation Center
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95 SC400 92 SC400 96 Ex
New (used) engine with 80k fewer miles for $650, installed with some new parts for total of $1500. Runs like a dream now.
Awesome! :thumbsup: Though with that money I would have bought another V8 Explorer to pull the trailer.
 
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shadowless127

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'01 EB AWD 5.0
Awesome! :thumbsup: Though with that money I would have bought another V8 Explorer to pull the trailer.

I have often thought about selling my X and buying another one with fewer miles but then I realized that I know everything wrong with the truck and I know what needs to be replaced, not to mention I know what has already been replaced. Buying another used vehicle for cheap isn't always best because you're essentially purchasing a bag of mixed nuts. If my engine goes I'm just going to get a JY one with like 100K miles for $450, maybe swap in a different cam and springs, have it installed, and be done with it.
 
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