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

 

Whoa! I can't tell you what's wrong with your engine, but I'd definitely think twice about that 2000 mile trip you have planned! Beg, borrow, or steal (rent) another van, if that's the main consideration. Lower engine noises could be a scary SOB to drive with, and you want piece of mind, right? How you gonna get it without opening up the lower end and figuring out what's-what? (Sorry, I don't know if the pan can be pulled in the vehicle, but I haven't seen one yet that wouldn't come out once an engine mount or two was unbolted). And, if it's the mains, what then? New bearings? What if one of the journals is gone? You going to pull the crank and have it refinished?

No sir, for my money I'd call a rental company. Sure, money may be tight and all that, but just think of what "could be"......

Good Luck to you!

 

does the sound change when you put the truck in gear could be the flexplate, sometimes theys sound like a rattle or knock when they have a crack in them.

 

Yes, make sure the flexplate and tranny is tight. Also while your there, make sure the starter isn't sloppy loose.

Disconnect the accessory belt(s) (serpentine?), and run it. If the noise went away then it's obviously something on the front such as water pump.

Use a long screwdriver or broomstick and probe around the block. (A stethoscope is very nice here)

Other possible sources;
Stuck/collapsed lifter(s)
Fuel injector
Broken coil spring(s)
Bent pushrod(s)
Loose or damaged rocker arm
Loose timing chain or timing gear coming apart (could be hitting front cover)
Damaged distributor gear
Damaged cam bearing(s)

This had become such a frequent problem they named a car after it - the Ford Probe. Don't feel bad I'm driving with a bad wrist pin until I can finish my stroker.