So this is a long shot I had a lifter knock on my 4.0 it’s a 2001, so replaced lifters, pushrods, rockerarms, springs changed the oil (no metal flakes) and I have perfect oil pressure but yet it’ll run for 10-20 minutes fine then knock. Once you let it cool down it’ll run great but it’s persistent and never changes I don’t know if it’s a oil pump or fuel related but it’s super confusing maybe someone had this issue before. The motor has 180,000 on it
Old fart with a wrench
If you're talking about lifter rattle, that's normal for a 4.0 and they will run forever that way, unless it's something like a cracked piston skirt, I wouldn't be too concerned.
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- Join DateAug 2011
- LocationPrescott, Az
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- Year1990
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Isolate the knock using a mechanic's stethoscope.
Quote:
I’m running 10-30 I have been for awhile now but it was super clean I’ll take a video of it but it’s at my buddy’s shop right now Originally Posted by tech
what oil are you running ? and maybe a video would help if we can hear the knock .