I took my truck yesterday on a little road trip driving all highway at 60-65. The total distance was 168 miles round trip. About 3/4 of the way there, the motor started making a really weird noise that i have never heard before, its a really raspy sound. All the gagues were fine while driving, but i pulled over to check everything out. Popped the hood, everything looked okay. The oil was full but the dipstick was smokingnot bad, but none the less smoking(normal??), but everything seemed to be okay.

I started the truck back up and it idled fine. but still had the raspy noise. I didnt know what was wrong, so i kept driving home. The noise was there the whole way home. At take off, it was missing in every gear around 2700-3000 rpm's. It was hard to get above 55...

When i got home and let the truck sit awhile, it cooled off and the sound went away. but as soon as it heated up, the noise was back. I havent had time to pull any codes yet, but I will do that tomorrow. In the mean time i wanted to know what you guys thought may be the problem.

Vehicle Specs:
1989 F250 351w 4x4
31,000 org miles
C6 trans
4.10 gears
K&N FIPK intake
all synthetic fluids

 

first lets start by cheking codes

here is howw

Ford Fuel Injection

 

Haven't had time to pull the codes today, as stated in the first post. Computer at work helps to waste time and post threads trying to get ideas about what may be wrong. I am able to pull the codes. That will happen tomorrow. Thanks for the post!

 

What kind of truck you got? does it sound like an exhaust leak, blown head gasket? I burned a hole in a piston once and the engine lost power and was blowing oil out the dipstick tube.

 

Its an F250 and it deff doesn't sound like an exhaust leak. I looked at the motor and felt around the block, it didn't blow any unusual heat around the heads or exhaust manifolds. The motor really didnt seem to feel like it lost any power, just was missing in each gear around the stated rpm range. No oil was blowing out of anywhere...

 

Man you`ll have to check it out , it could be alot of things,check the timing,fuel at the rpm that its acting up,try to narrow it down.Let me know what you find out.

 

for the raspy noise, check the fan shroud. See if it shifted and maybe the fan blades are hitting the edge. That happened to me once. With the engine off, turn the blades by hand and see if it is hitting anywhere.
For that matter, check if any of your external rotating items are hitting on anything.
I also had an air pump make a nice grinding/raspy noise once when the internals shot craps.

 

The earlier trucks from this generation are notorious for blowing though alternators as well.

Tim

 

Well fellas, codes aren't going to help me out with anything at this moment. The KOEO test showed nothing... 11-11. The KOER test only gave me a 44 twice and I was aware of this already. (Thermactor Air Injection system inoperative (Right side). So back to square one.

 

Well, when i went to warm the truck up to run the KOER test, the raspy noise was still there, but it wasnt missing in any gears that i was aware of....

 

There were nothing on the motor that was hitting on anything... the fan was inline and nothing that rotated on the motor was even close to hitting on anything.
Is there an easy way to tell if this happened? Maybe start the motor and listen to the airbox? Problem is, the sound isn't heard at idle, at all... Im stumped.

 

You could pop the belt off (takes no time at all with the right wrench) and spin the air pump by hand. It should be fairly easy to spin by hand.

Also the power steering pumps can get pretty noisy. It's a Ford thing. I can pick out old fords in parking lots just by the sound of the steering pumps.

beyond that, it still could be a whole slew of things. Have you isolated the noise variance to engine or driveline.? Does it make the noise only while you are moving, or will it make it when you are stopped too.

I just recently had one of my brake caliper metal/rubber holder inner pins back out on me and rub against the wheel. That made a nice grindy noise. I never did like that design.

It could also be the pump on the transmission going out. That never sounds healthy. There are just soooooo many rotating items on our trucks that could go bad.

 

The noise isnt there at complete idle. But if you rev the motor, you can def hear the raspy noise...

The noise almost sounds like it is coming from somewhere underneath the truck because when you are sitting in the truck, I think it is coming from inbetween the bed and the cab. Transmission problem here? I checked the fluid, it was fine, not burnt or even discolored.

 

Didn't you find a rusty crossover tube at the back of the motor? You need to fix this before you burn a hole in a piston

 

The hose def broke off of the motor somewhere, but i couldn't exactly find where. Does anyone know what this piece is???





This end didnt seem like anything was supposed to be in it, so ithought that it was just something that released/sucked in air for the motor or something.