I have an 1988 Ford E350 MOving van, that I plan on taking on a 2000 mile trip in a week or two. It has an 460 FI motor. It runs well, good power.. no smoke. However lately I have started to hear a kind of rapping from the bottom of the motor when standing beside the vehicle. It is not noticeble from inside the truck. The noise does not sound like only a single knock, but more like multiple tapping noises. like there is more than on source of noise possibly more than one rod or main?. The oil pressure is good. 60 pounds or better when cold, and then once the engine warms up, will go to about 45 pounds. If the engine is reved it will go up to 60 - 70 pounds again. The noise does not appear to change in tone or volume if the vehicle is under load, and appears as well to increase when the throttle is pressed. Also, as the engine gets warm, the noise is still present. I have crawled under the truck, and the noise definitely sounds as though it is coming from bottom of engine. I tried pulling one plug wire at a time, which did not appear to effect the noise either.

Can somebody help diagnose this, and if at worst it is due to rod or main bearing knock, does anyone know if the pan can be pulled while engine is still in vehicle, and would replacing bearings help or for how long. or could I get the engine to make the trip by taking it easy and running thicker oil... all responses will be greatly appreciated...

Thanks

 

Can you pull that motor real quick and do an overhaul?

Long ago I asked a guy about a problem I had on a bike when I was going to ride an upcoming enduro....he quoted a famous racer in saying "...I've finished a lot of races (with a problem like that), but I've never started one."

Will your route include many places where you can enjoy being stranded?

This is a no-go situation, imo.

 

First I would take the oil filter off & cut it open & see if there are any chips in it.

 

I just thought I would ask beings that no one else has , does this have a manual trans or automatic? It may be possible that your hearing a noise coming from there and transferring , I have seen flex plates crack and sound like a rod bearing and clutch noises also. another shot in the dark is a possible exhaust leak .

just my .02

 

Rod bearing noises generally go away under slight load. Valve train noises dont. Your oil pressure is good, but one bad bearing wont throw your oil pressure off much. unplug one injector at a time will it is running. If the noise goes away you found the dead hole or bad rod.

 

I did try removing plug wires one at a time, I did not hear anything noticeble. The noise does not sound like a deep knock, but more like a lite clatter. It sounds as though there must be more than one source of the noise. I notice it at idle, and it speeds up with increase in throttle. If I place the truck in gear the noise still seems to be there. I removed the inspection plate, and the flex plate looks good and it seems well secured to the crank and torque converter. I have resolved myself to the fact that I should drop the pan, and verify the rod bearings before I go much further.

 

I would pull the valve covers off first, make sure you dont have a bent pushrod or loose rocker arm.

 

Sounds right about the rocker arms and push rods. Could also be collapsed lifter(s).

 

could be a lifter or a worn camshaft. Pull the valve cover and check the lifter preload., it should be about .02 of an inch.