Hello I have an 82 f-150 with a 302 67000 miles and problems when I drive it and let it worm up on the high way and then get off my oil pressure drops to nothing and the valves tick (i think) if i dont give it a little gas them it goes back up and the pressure dropes a little on the high way once it gets warm i use 15w-30 oil I am tierd of fixing this truck some one please help me

 

my 91 F150 (302) does almost the same thing. When coming down from freeway speeds the oil pressure goes down then I either have to rev it up a bit or put it in neutral and the pressure comes back up. Also the oil pressure seems alittle lower than normal. Would heavier oil like a 20W50 or a straight 50 help any? The truck has 96,500 miles on it but it seems to run just fine.

 

i will try some hever oil. i just did a head gasket and had some water in my oil but only drive it abought 10 miles just to get it home could i have mesed dome thing up with the water or put the moter back to together wrong

 

well, the cause would be many things. Thicker oil is just a temporary fix. Usually its the main bearings, but could be a sludged pickup too. Try running a quart of Marvels mystery oil through it on your next oil change. MMO will clean out your engine, so change your oil again at about 1000 miles. Could be a sludged pickup and when the oil is cold it does not flow, and when hot it does. By puting thicker oil in it, you are decreasing flow, which if it is a pickup problem, you will do more damage to your engine. If it still does it, drop the pan, replace the main and rod bearings, and get a melling high volume oil pump.

 

so the next time I change my oil, replace one quart of Valvoline with one quart of MMO and drain at 1000 miles?

 

I think you need to get those worms outta there!

Seriously though, I think you need new bearings. I would pop the pan off and slide new rod and main bearings in there. This will improve oil pressure immensely.

What oil filter are you using? If it's a fram, switch to another brand, like a Napa gold or motorcraft. Frams are known to cause low oil pressure and valve lifter ticking.

Are you sure you didn't mean that you're using 15w40? I havent seen 15w30 around anywhere. I'd say use 20w50 and see what it does.

 

hello i just put a new gauge in now my presser seams to be abought 13lbs at idle and 26lbs on the high way. I am useing a fram filliter and rotella t oil i thought it was 15w-30 but i might be wrong i just put some of that Marvels mystery oil i just changed my oil over the week end then i saw the oil presser and quit driving it so i drained out abought a quart of oil then add the mmo i will chang it at 1000 miles i still have a tick and just had new valles put in what would cause this thay did not do it before i took the valve cover off to see if thay came loose but the valves where fine

 

i need spell check

 

Seriously, lose the fram filter. You will be amazed by the difference.

 

i will lose it and go to a napa what brand and wait oil do you sugest

 

I'd use a Napa Gold oil filter. For oil, use 15w40 Shell Rotella T, Mystik JT-8 Super Heavy Duty, or Chevron Delo. Dont add any additives like MMO on your next oil change, they thin the oil. That's not what you want if you're getting low oil pressure.

If it still has low oil pressure try a 15w50 or 20w50.

 

hello I drove my truck to work today. it is the first time since i did the heads. i drove it around a little bit but not too far. i thought i had a bad guage but my pressure droped out again, so I never did the bottom of a motor before. what do i need to know? do i have to pull the motor? should i take the crank some where to be turned?what about the motor could where the bearing sit be worn?

 

I'd recommend this first. It might be your oil pump might getting clogged up or part of the engine oil passage ways are gunked up.

Get a quart of Gunk Motor Oil Flush. Don't drain your oils yet. Just pour that entire quart into the oil crankcase. Start the engine and let it IDLE for 5 minutes only and turn OFF the engine.

Remove the oil cap. Drain the oil and remove the oil filter. Let it drain for an hour or so. Put back the oil drain plug and pour oil in the oil filter. It might take 1/2 quart to fill the oil filter 3/4 all the way with oil. Coat the rubber seals of the oil filter with the oil. Screw in the oil filter. Fill the oil crankcase with 5W30 for now. Start the engine and see if the pressure still drops. If the pressure holds, try driving it around.

If the pressure still drops, I would then first replace the oil pump, oil pump filter/strainer and see if that fixes the problem.

 

Unless you hear a loud rasping buzzing noise when you go over the top of hills, you haven't got a spun bearing. That's the only thing that could wear where the bearing sits.

To do it perfect, you'd need to pull the crank and check the runout, out of round, and wear on the journals. I'd say they're probably fine, they usually are unless you've got a bearing edge riding, or have a spun bearing. If you notice any blue spots on any bearings when you pull them out, you've got problems.

What I would do, is find a book about rebuilding small block fords. I'm not saying rebuild it, but it will give you torque specifications and instructions. I would pull the oil pan, and check the oil pickup screen first. If it's clogged with debris, remove it and clean it. This way you'll know and wont be scratching your head wondering if some miracle chemical worked or not. If it's not plugged, and it's probably not, I'd put some new bearings in it. All you do is, while you're under there, pull one rod cap at a time, and slide out the old bearing, and slide in the new bearing. The book will have more specific instructions than I can type here. Same procedure for the mains. After you're done, there's a procedure for setting the thrust bearing, where you have to pry the crankshaft forward and backward. The book will detail this.

If you feel like you have the time and money to pull the motor, then by all means do so. You'll get to check the crank more thoroughly, and it'll be 100% easier working on it on an engine stand than crawling under the truck.

Like I say, get a book. It makes it SOOOOO much easier.

Good luck!