A little background on the truck. I recently did an engine change swapping a new 351W in for the old. The new has flat tappet cams. All new accessories were put on the motor.

So a few weeks ago my mom took our 1988 F250 to pick up some furniture. On her way back, the car started making knocking noises and lost power steering. When I went to see what was wrong with the truck on the side of the road, there was what looked to be radiator fluid, albeit very little, in the engine bay. The belt was off.

I put the belt back on and made sure the radiator cap was tight, etc. and started the truck. It was hard to start but it did and then there was a bang. I turned the truck off and went to inspect. The power steering pulley sheered off and the shaft didn't move. So the power steering pump froze and caused the belt to jump.

Drove around town for a while trying to find another pump so we could change it out on the side of the road. Once that was complete, I started the truck again. It ran good and strong. Figuring everything was peachy, I got on the highway to drive it home. All of a sudden it started making a knocking sound like bad gas, and lost power. All gauges read normal. Pulling over to the side of the road again, popped the hood. There was once again radiator fluid in the compartment and there was smoke/steam coming from the oil cap. I had it towed home from there.

My guess was that something with the power steering pump freezing caused damage to the water pump and the fluid in the engine bay was from the weep hole. I figured changing the water pump would solve the issue.

A few days later when I had some time, I went to start the truck. It backfired bad and didn't start.

I then proceeded to check compression. #1 cylinder was reading no compression. Theres compression in the other cylinders but some are lower than others. Cylinder 5 read 80 lbs but the rest read 15. I drained the oil and there was no evidence of water in the oil. After pulling the valve cover I noticed that a rocker arm is loose. The stud seems to have the same amount of threads as the rest that dont budge but there is lots of play. Im assuming this is where the knocking noise was coming from.

Turning the engine over shows that everything appears to be working as it should. Timing is still right and the valves appear to be opening and closing. You can hear compression building but you also hear a hissing noise like air is being let out when the distributor is pointing to about the 2 o'clock position.

I still think that the water pump is probably bad, but what could be causing these symptoms? I think I've ruled out a blown head gasket. Melted piston, bent valve, burned valve, bent push rod? The possibilities seem to be endless.

Thoughts?

 

With those numbers I think she is done...only options are to rebuild or replace the motor again IMHO

 

I just did a leak down test of sorts on cylinder one. I pumped 60 psi of compressed air onto the cylinder. It held 60 pretty steadily. No audible hissing from the exhaust or the oil cap. The gauge on my compressor showed 55 psi after a few minutes. It doesn't seem to have bad rings or anything. Still reads no compression with my compression tester. I surely hope that isn't the case Slip...

 

I would agree with you guys, Your motor is done, You should have steady compression within reason all the way across the clyinders. But if your not loosing any compression out of the cylinder , it just sounds like a badly worn engine,

Did you open the throttle all the way while doing the compression? your numbers will change,

My truck is 170 all the way across the board