Howdy folks, I have a 1998 jeep tj Sahara that is knocking on startup, goes away at idle bit comes back around 3k rpms but she still runs and drives. Some back story here on how this happened was one night coming home from watching a basketball game, I decided it would be fun for shits and giggles to "race" my freid in his dodge 2500. I was just cruising and he rolled up beside me and I gave her some gas up to about 60mph. Well that didn't last very long cause the oil pressure dropped and a loud knock started and I for sure though I blew the motor. As soon is I heard the knock I shut it off and coasted. My friend who I raced being a good guy gave me a tow home. Now this knock has been in existence ever since. I had I taken to a local mechanic and he replaced the oil pump and said that in cylinder #6 the rod looked bent and more than likely the engine block was shot and I was better off putting a new engine in it which would cost around 4k. I didn't do it. Fast forward a few months I decide to take a look at the jeep myself and drop the oil pan and take a look at this bent rod. Upon inspection everything looked okay except for the fact I found a shit ton of metal flakes in the oil. They were not magnetic which had me wondering. I took a look at rod #6 and it didn't look bent to me and the cylinder walls looked alright. However, the camshaft on the other hand didn't look too hot. I would've taken the bearing caps off but I don't have a torque wrench. Anyone have any ideas what could be the issue? I'll post the vids of it knocking on startup also
Help diagnosing engine knock / tick
- Thread starter BanginChicksWithInline6
- Start date
Rubicon John
TJ Enthusiast
Judging by all that sludge I’m seeing, your engine has had a hard life. I don’t know that I would repair anything that sludged up but you could find a used or even a rebuilt engine for fairly cheap if you look around.
Yea, it was a gift from an uncle and I got it with 215k miles on it. It currently has about 220k rn
That is bearing material on the paper towel. Bearing material is not magnetic as I'm sure you know. The video sounds like classic bearing noise. Motor is toast man. Pull it and rebuild (it in to a stroker 
) or swap in a junk yard motor. Sounds like your mechanic doesn't know his ass from his elbow. Go somewhere else.
) or swap in a junk yard motor. Sounds like your mechanic doesn't know his ass from his elbow. Go somewhere else.
John Scoggins
TJ Enthusiast
Could I replace the rod bearings and more than likely the crankshaft and get some more life out of her?That is bearing material on the paper towel. Bearing material is not magnetic as I'm sure you know. The video sounds like classic bearing noise. Motor is toast man. Pull it and rebuild (it in to a stroker
Possible but not advisable. Depends on the crank's journals and if it's the main or rod bearing. Mark all the caps with numbers and directions then start pulling them and check. After that much metal went through my motor I'd rebuild it regardless, but if you don't mind wasting your time if it doesn't work, parts would be cheap to try and it might keep you on the road for a while. Maybe.
I hydrolocked my motor once upon a time being a dumb ass. Long story short, I bent #1 rod bad. Still have it. I pulled it, had the old piston pressed on to a new rod, threw a new bearing in it, and ran it for like 20k more miles until something probably unrelated died.
I hydrolocked my motor once upon a time being a dumb ass. Long story short, I bent #1 rod bad. Still have it. I pulled it, had the old piston pressed on to a new rod, threw a new bearing in it, and ran it for like 20k more miles until something probably unrelated died.