Does anyone know what this problem could be.

I took my 83 Bronco on a 80 some mile trip so I could have the insurance company look at it. Ever since then, my truck sounds like a diesel. That's the best way I can explain it.

When I rev the motor kinda high (3,000 RPM) it has a bad knocking sound... kinda like that distinct sound of a diesel truck...

A friend of mine told me that it sounds like the rocker arm? Is there any way I can find out for sure without taking it to a shop? I know if it is the rocker arm.. then it's pretty bad. ( I think)

So,. Is there any way I can find out for sure without taking it to a shop? and.. if so.. is this pretty serious?

I have a 86' 351 Winser..

Thanks alot.

 

yo, get a piece of hose or cardboard tubing (from giftwrap) and use it as a stethoscope...one end on the valve cover(s), and listen as you rev it up by pulling on the linkage. Could be pre-ignition..have you changed gas stations recently?..worse is a bearing gone bad.

 

Thanks for the help. Ok, when I do this.. am I just listing for the knocking? or is there something else I'm looking for?

I changed the oil the other day and noticed that the front seal is leaking.. could that be part of the problem?

Thanks again.

 

Listen for that knock..hopefully it is in the push rod/rocker area and may just need an adjustment..usually that "rappet" noise is a click..sorta like when you type fast on a keyboard..if so, then it is ez to adjust or have repaired...
did you lose a lot of oil 'cause of that seal leak?
if you did, then it could be anything else..

 

No, I didn't loose alot of oil, so I guess that's good.

The knocking is constant with the rev of the motor.. sometimes dieing off for a few seconds when the rev of the motor surpasses the sound..then it catches back up and starts again. to me, it sounds like steel on steel. I also noticed that it doesn't do this when the truck is cold.

I'll try your suggestions, thanks alot for all your help.

 

Had same problem with my 95 302. turned out to be a stuck lifter bent push rod and worn out rockers.
Replaced all on both sides.

 

hipropos, thanks. Was it an expinsive repair?

I hope not!

Thanks again.

 

do you hear even the faintest of nioses while she is cold?

 

No. I don't seem to hear anything. Kinda strange. Does that tell you anything?

 

what type of climate you in and what weight of oil you use?

 

what type of climate you in and what weight of oil you use?

 

I think it has 10w30 right now, and I live in Colorado... it's been 70's for the highs and as low as 35. Not humid... not much rain..

I had a couple people listen to it and it's coming from the top of the engine for sure and they seem to think that one of the rocker arms may not be tight. I'm going to take off the valve cover and torque them down and then go from there.

 

I thought fords were self adjusting on the stock engines.

sounds like a bad lifter or possibly a weak/broken spring. but not rulling out a bent pushrod.

 

 

It only cost me 480.00 the dealer paid the other half.
check this out, bought my used bronco (95 302 eddie) with in second day wiper motor went out, next day going to shop a rock split my winshild, next week locked up the lifter, remote door unlock stopped working and now cruse control is out too.
now im super modifing, cut catty off, new tune kit thru mcford.com $85.00 plugs, 9mm wires, rotor and cap, pvc and fuel filter. firestone bought me new shoes.