what causes low oil pressure, could it be due to oil level slightly below "add" on dipstick or more serious issue?

Will truck run ok with 12 month old gas or should i drain it?

Motor is running rough but has not been run in a year, don't know how it ran back then. It idles well, but is plugged up when i hit the pedal.

It is puffing blue smoke out exhaust, not a lot, but it does smoke. Would straight 40wt help or other additive?

Miles are 214K, i think. F150 4x4 straight 6, 300 cubic inches, four speed.

Any comments would be apprec, I might buy the truck for a hunting camp vehicle.

 

Your oil pressure wouldnt change if you are low on oil untill it almost ran out because the pressure measures what the pump is pumping and since it cant pump all5,6,7 qt's at once it only needs a few to work.
I have heard a lot of people say to drain old gas but if it runs with it you might as well use it and then fill up with a fresh tank and see what is wrong. My 64 sat for years and started up with old gas--no problem.

If that smoke is white and not blue with a smokey smell them the engine is running lean rather than burning oil. If it is running lean that might answer some of your throttle response problems i.e. choke, bad gaskets, all kinds of stuff if it is carbeurated. If it is a fuel injected engine I am not sure--maybe a plugged fuel line in either case if it has been sitting.

 

What year is your f-150? My grandfather has one with 200,000 miles, he only changes the oil once every 15,000 or so and then, he uses SAE 30. He's been through a few oil pumps because of all the sludge in the motor...

It is possible that the pick-up screen in the oil pan is clogged, inspecting that requires dropping the oil pan, and you have to jack up the motor a little to do that... and while you're in there you might as well swap out the pump for safe measure, i dont think they're very expensive.

I wouldn't run the truck on real old gas, especially if it's fuel injected (I think the older, thicker gas can wreak havoc on injectors). I'd say drop or siphon the tank, and definitely install a new fuel filter.

Galazie is right, the oil pressure isn't really related to the oil level in the pan unless it's so low that there isn't enough left to pump.

White smoke can also be a sign of coolant/water getting into the cylinders, so keep an eye on the coolant level as well.


Hope that helps!

 

Thanks for some good info. To further clarify, the vehicle is a 1977 F150 4x4 that has been used at camp for the last 10 years, never on hard road during that time. After thinking about it, the motor probably has 214k, not 114. The white smoke seems related to worn rings since it is buring oil.

Should I add and additive to crankcase or is that asking for trouble on such an old motor without knowing the history. ie, don't know what mystery oil or Restore does, but something like that.

Also, is an operating temp of 190-200 deg normal?

How big of a project and how expensive is replacing the oil pump? I may need to take it in.

 

Well, here's what I know and I am by no means an expert so...

On the 94 Ford, once the oil pan was down, it was relatively simple to get to the oil pump - I think it's held in by 2 bolts and the unit is installed with a small gasket. It should also be pretty simple to remove and clean the pick-up screen, but I think the hardest part will be just removing the oil pan and dealing with such a dirty job. Not sure on the 77 but you may have to jack the motor up some for there to be enough clearance to remove the pan so be prepared for that. Carparts.com has that pump for about $30, so add gaskets, new oil and filter, you're probably looking at around $70.

I dont know anything about Restore, but my grandfather at one point drained the oil, and added 3 quarts of 10w-30 and 2 quarts Mystery Oil, supposedly this would help clean some of the oil passages etc. in the motor. But I dont know if it's a good idea, can anyone shed some light on this one?

Typically, oil burning in the motor results in a blue tint from the exhaust, not white. White usually means steam, so I would still keep an eye on the coolant level. And 180-200 degrees is probably about right.

Depending on what you can buy the truck for, if absolute worst case you decide to have the engine rebuilt, you can at least know afterwards that the engine will be great for quite some time. The 300 Straight-6 is an incredible engine, arguably one of the best built motors Ford has ever made.

Hope that helps!

 

My 84 300 I used to have ran about 175 degrees. yours may be slightly warm, what kind of fan is on it, if it has a clutch fan thats probably your problem, especially if it is the origional. the old fords usually didn't run over 190. If your smoke is white, it is coolant, probably coming from blown head gasket. If it is blue it is oil, if its black its fuel. I would change plugs and drive the old gas out and keep an eye on your fluid levels.

 

Aaaaaahh.. a '77, very nice. I had a '79 with the straight 6. It had 100k on it and ran like new. Unfortunately, I don't know the answer off hand, but I can tell you that the Haynes repair manuals are great for this stuff. You should pick one up. It will help you figure out the problem and tell you exactly how to fix it.
Any problem you run into with that truck should be an easy fix. The '73 - '79 is such a popular model, every mechanic knows about them.
Good luck

 

I suspect your low oil pressure may be a sign of very worn main bearings. Most ford engines can live a long time on low oil pressure.

I have a 1979, F-150 with 165,000 miles--runs like a timex. I have had this truck since 2/87. I have never had to do any internal work to this 300 C.I.D. engine. My 300 still has the orginal carb. (which has had two accelerator pumps installed). Still has the orginal alternator and distributor.

Recently, I spoke with a friend of mine that works for a large construction co. that owns mainly fords with 300 and 351, V-8's. He is a chevy man; however, his experience in construction has lead him to believe that Ford Trucks are King.

He said he has seen employees add 4 or 5 quarts to a ford truck that had 100,000 miles on it, then see that same truck give another 150,000 miles of trouble free (internal engine) miles.
If you run a chevy engine low on oil or at very low oil pressure--that engine is toasted.