Went wheeling and picked up a knock

[76K20]

Went with some of the guys from work to the Badlands. About an hour into it we went to a rutted section with some mud holes in it. I hit the ruts a little harder than I should have and after I came out of the hole I had a nasty knock from the bottom end. I have no oil pressure but the truck runs great. The truck never got above 4,000 RPM so I highly doubt it's a spun bearing. I'm thinking either oil pump gave up or the pickup tube got knocked out.

There is no water in the oil and just a VERY little bit of water in the carb. The spark plugs smell like gas and that's it. Any ideas?

 

[drob1351]

id say check to see if you hit your oil pan on something and blocked the oil pump suction. if thats not it, then id say that pickup disconnected from the pump.

 

[MTMike]

Definitely inspect the oil pan, and if it checks out, pull the oil pan an inspect things.

 

[toomany]

I had a nasty knock from the bottom end. I have no oil pressure but the truck runs great. The truck never got above 4,000 RPM so I highly doubt it's a spun bearing.

Even though you say the motor never got above 4000rpm, you could still have spun a bearing. High load/low rpm situations are harder on the bearings.

If you have a knock, and no oil presure....you will be in for a rebuild. At the very least, new bearings. And if it is a bad knock, the crank turned (if it hasn't been beaten too badly yet).

 

[76K20]

It was never under a heavy load. I never got into anything nasty enough to even begin to put a load on that engine.

Regardless I'm going to pull the pan off and inspect it tomorrow night. Hopefully there's no real damage other than maybe turning the crank and slapping new bearings in. If there is anything worse than that then I will just plan on turning this into a nasty 355 and be done with it.