I trade in 2000 F350 for 94 F150 with my boss.

I ran some trouble with this and I already knew it had issue before I trade.

It had vibration idle it isn't miss it more like vibration like cheapo oil-less air compressor. They say it been doing that for long times so it doesn't bother them.

Coolant I would say HORRIBLE. It look it was RUSTED water. They told me few days later it run out of coolant and they pour water that was 1 year ago so I am sure engine is still fine. I was wonder if bad head gasket could affect coolant to be rust?

Oxygen sensor it had code 172 and 173 it say lean and rich so I start getting worry if it was coolant go in exhaust and ruin oxygen sensor?

 

Hmmm... numerous issues. What engine does this vehicle have?

Regarding vibration, try loosening all the v-belts [serpentine belt?] or remove them and start the engine. See if the vibration disappears. If it does, then one of the driven components [i.e. P/S pump, alternator, fan assemble, etc.] is causing the problem. Do not run the engine for long or it will overheat, due to the water pump not turning.

Drain, flush and refill the radiator with proper ratio [normally 50:50] antifreeze. The coolant will rust without antifreeze and it rust prohibitive properties regardless of whether the head gasket is good or bad.

 

It 1994 F150 4.9L 300 with 5 speed.

I am looking at engine mount on driver it look it was broke or not sure.

Will try get video of running.

It had serpentine belt but it definably engine related since there random if I almost stall it had worst vibration like impact wrench for few seconds then it drop to normal vibration like oil-less air compressor.

Going try flush coolant. It ok to run straight water for like 50-100 miles try clean crap out before put fresh coolant in it.

 

Spend 3 hours try flush. Can't believe how nasty coolant come out. It wasn't ever green it look it was straight water and it left GIANT rust stain on driveway.


Found out it wasn't bad oxygen sensor it was fuse on #16 which control oxygen sensor were blew.

Clean IAC and it does change engine behavior different. Possible bad IAC.