just picked up a 94 f 150 with a 302. i am concerned about a knocking noise the engine makes. it doesnt really sound like a rod to me. it only makes the noise at idle and does it worst when cold. when its warm its barely noticeable. i was questioning oil pressure so i installed a guage and at idle cold it has 50 psi and warm 25. it goes up with rpm also just like it should. so im looking for ideas on where the noise could be coming from. collapsed lifter? idk thanks!
oh also does this year of 302 have a roller cam? i believe it does

 

Have you changed the oil yet?

 

no i havent but it has a motorcraft filter on it and the oil looks almost new

 

It is more of a knocking sound, or does it sound like an exhaust leak?

I'm going to bed now, but I'll check on this again later. Hopefully someone else can chime in in the meantime.

 

its more of a knocking, the truck runs pretty good but not perfect

 

How many miles on the truck?

I have the similar problem, but after teardown of the top and lower end it was evident what the problem was. Oil Starved bearings, lifters, cam, crank.... Could also be wrist pins, could also be piston slap, as you stated yours got nearly quiet after warming up.

If you decide to change the oil, do so in a clean container and get a funnel with a screen. You can see small shavings of engine material better if you drain the oil catch can in to a another container with the funnel.

You could see if it is rod/cylinder related, simply by pulling the spark plug wires individually to see if the noise is cancelled out when disconnecting.

There are many theories, but only time and/or tear down can give you insight.

Hope this helps.

 

it has 131 k before i got the truck the previous owner did head gaskets and i was thnking maybe they didnt adjust the rockers correctky or something but idk

 

I believe the knock was there before the head gasket change. You could just drop the oil pan and check the mains and see what they look like. That will give an indication as well.

If the truck had anitfreeze mix with the oil from a blown head gasket for an extended time, that may have introduced it or made it more pronounced since it's hard on bearings.

 

well i would drop the oil pan if it was just that easy, pretty sure the engine needs to be pulled to do that correct?

 

No, just disconnect the exhaust from the exhaust manifolds. Drop the "Y" pipe, may have to remove the crossmember from under the tranny, and then you can loosen the motor mounts, and then using a tranny jack, gently start to lift the engine only with enough room to remove the oil pan.

You may have to remove the fan shroud. Some have done with it in, others haven't. My Chilton and Haynes both say to and also to remove the plenum. Has been others that had to remove the plenum since it hit the firewall when lifting it up. It's a slow process to remove the oil pan, but once you have, you will be able to again with ease after the 1st time. It's a game of patience and second checking. Ive done it to both my 4.9 and 5.0.

The 460 is what I have heard is impossible without having to pull the motor. I haven't done it. But if you want help, just post back and I'm sure other members can help you in your questions.

If you decide to do this, remember to use a block of wood as a load disperant and not the plate from the jack. It's also good to have some 1x2 available to slid in between the engine mounts to help with the 1 inch lift you need to remove the oil pan. I used 2 jacks, one to get it lifted and the other under neath the transmission to help support the weight. Mines 4wd, so the added weight of the transfer case bears a lot of weight.

 

ok and what will i be looking for? i mean i know what a scored bearing looks like but do i need to pull all the rod caps off? also as long as im in there i would like to put a high psi oil pump in it. any recomendations?

 

You are looking for fatigued, blued, pitted, radius ridden bearings. Also for gouges run in them and on the crank. If you want you can pull the rod bearings as well. You can check for wrist pin problems as well. With it open, your eye will help diagnosis and everyone here that can post back with info.

I do not recommend a high psi or a high volume pump. Just spend $25 for a new melling oil pump.

I'd say if you have a week or so, you can have a very exciting time doing this project and what you learn with the project and here may lead you into new directions.

don't be afraid to ask since not asking can cause engine failure sooner than later. My learning came at 9, with checking the oil in the lawn mower and now I can't wait to have a garage to work on my '81 courier!! YEAH!

an invaluable tool as well, would be to purchase a Haynes manual and PREFERABLY if you can find a Haynes manual from the late '90's, perhaps on E-bay! Any repair manual will help answer some questions you may not be willing to wait for here. But any considerate member will be willing to help guide you in the right direction.

 

ok well heres the thing, if im gunna put new bearings in im gunna pull the engine and replace the rings and at least hone the block. also id like to upgrade the cam and do a timing set. im wondering if my 94 has a roller cam? also id like to do a set of timing gears for the whine at idle

 

The 94 has a roller cam , when you take it apart you will wan't to take everthing to a machine shop to have it checked , rods , crank , block....Lew

 

ok ill keep you guys posted, ive got a bunch of other work to do first though ( supercab coners, 6 inch suspension lift) then engine last