oil recommendation for 1994 F150

[CATERHAM]

If cold start performance is what your after don't be afraid to go with an inexpensive 5W-20, it will be fine.
Now if you really want to spring for a full syn' oil, go with the M1 AFE 0W-30 I suggested for your Honda. At freezing (32F) and below it is actually lighter than a typical 5W-20.

 

[QuadDriver]

Originally Posted By: Execut1ve
Hi everyone,

I am looking for oil advice on my 1994 Ford F150 A/T 5.0L 4wd with around 154k mi. I am in OH so temps range from 0F in the winter to 100F in the summer. I got the truck for free from my father-in-law when it had about 152k mi. He is not the first owner. I don't know how many miles it had on it when he got it, but he did remark that he doesn't remember ever changing the oil during the time he owned it *yikes* I changed the oil as soon as I got it and put in Castrol 10W-40 conventional. It's going to be due for another change soon which I will probably put off till the weather isn't so butt-cold up here. I would like to put full synthetic in but I have a leaking rear main seal and oil pan gasket to replace, so I may wait until those are fixed before I make the switch. I would be glad for any advice I can get regarding oil brand, type and grade for the truck! thanks!


10-40. period.

ford windsor engines run on 10-40 and nothing else. (you can make the case for 10-30 in the gt due to the higher revving nature vs the truck motor) but 10-40 unless the engine is built with hivol pumps and filletted journals etc.

 

[QuadDriver]

Originally Posted By: Execut1ve
I plan to have the leaks fixed as soon as I'm able, just difficult to do a rear main seal & oil pan gasket without an engine hoist

you can do this without an engine hoist, but the tranny is coming out. I didnt read that it was a 4x4?

anyways, you can get the pan down enuf to work the 1 piece pan gasket off, the multi piece is easier. but anyways, the truck sump is in the rear where you have more room to work..

one more thing, pull the tranny inspection plate (I am assuming auto here), if there is oil on the INSIDE, then the rear seal needs it. if not, you can skip that - the rear end of the pan gasket sides and the rear neoprene really really goes bad when it shrinks and hardens. I dont see bad ford rear seals that much since they went 1 piece.

 

[Execut1ve]

Originally Posted By: Execut1ve
Hi everyone,

I am looking for oil advice on my 1994 Ford F150 A/T 5.0L 4wd with around 154k mi...


yeah the problem is I don't have a transmission jack either. while I"m down there I figure I have no excuse to not do the rear main and also slap in a new oil pump while I'm at it. what's leaking is either the rearmost portion of the oil pan gasket or the rear main seal or both. I have crawled around under there enough to verify that's where the oil is coming from. And according to my Chilton's manual, oils thinner than 10w-40 are fine to run as long as the temperatures stay low. For example, 5w-30 can be used between -40F and 60F (although I should add it was written in '97). What is your source for saying the Ford Windsors run on 10w-40 exclusively?

 

[QuadDriver]

Originally Posted By: Execut1ve
[What is your source for saying the Ford Windsors run on 10w-40 exclusively?


About a half billion miles of testing.

Unlike the maddenly small oil passages of the chevy v8, ford drilled some proper holes so does not suffer the pump/frictional heating of the oil, but ford did not increase the pump volume, pressure or bypass. whereas a chevy requires a cooler in all semi or hd applications to keep the oil in grade, ford does not for a wider range of operating temps.

as a result, you can run a 10-40 in the dead of winter in a windsor, and when the oil flows better hot when towing, you are gonna want the 40 part of the 10-40 more so than a 30. as mileage increases, for 4 decades users have reported less instance of bearing and tappet noise on startup using the heavier grade.

now, worldwide experiences aside, on my own front I put about 1/4 million miles on the same engine you have using only 10-40. at first pennzoil, being a loyal pennsylvanian. then amsoil from 20K to about 150K when I discovered that castrol made a syn 10-40. the engine lives today in a mustang. (the trucks frame was not able to handle 18+ years of NY and PA salted winters)

(as a side note, dont put 0w or 5w anything in a old school ford engine especially the I6 unless you have a thing against bearings or watching the oil pressure drop to 5-10psi hot at idle.

 

[QuadDriver]

Originally Posted By: Execut1ve


yeah the problem is I don't have a transmission jack either. while I"m down there I figure I have no excuse to not do the rear main and also slap in a new oil pump while I'm at it. what's leaking is either the rearmost portion of the oil pan gasket or the rear main seal or both. I have crawled around under there enough to verify that's where the oil is coming from. And according to my Chilton's manual, oils thinner than 10w-40 are fine to run as long as the temperatures stay low. For example, 5w-30 can be used between -40F and 60F (although I should add it was written in '97). What is your source for saying the Ford Windsors run on 10w-40 exclusively?


well, you are gonna need one. I read back and saw that yes you are 4x4 so unless you are fond of taking the xfer case and tranny down as many pieces, you need the jack, and at least some sort of long reach floor jack to get the tranny high enuf to get the frame member down.

if you have a long reach floor jack with the 1.375" saddle bolt (I think that is the dia.) there are a few tranny adaptors you can get from like Mr tool or harbor frieght.

 

[Execut1ve]

mine is the 302 V8 fyi not the 300 I6. I'll probably buddy up with a friend who has an engine hoist and just do it the hard way, it'll give me a chance to get at some of the stuff on the back of the block (knock sensor) that needs to be fixed, so I don't mind terribly

 

[Georgiadave]

Just a thought for you. The lower intake manifold seals often leak on these engines, and oil drips down the block. You may wnat to check this area carefully.

 

[Execut1ve]

I'll check it out, but I know for sure that the oil pan gasket and probably the rear main seal are leaking

 

[Execut1ve]

Originally Posted By: QuadDriver

as a side note, dont put 0w or 5w anything in a old school ford engine especially the I6 unless you have a thing against bearings or watching the oil pressure drop to 5-10psi hot at idle.


out of curiosity, why would 0w-xx or 5w-xx have any effect on anything at hot idle? I was under the impression that 0w-40 and 10w-40 have the same viscosity at running temps; the only difference is the 0w-40 is thinner at cold startup temps.

BTW I feel ya on the rust and road salt... I got a healthy coat of rust on just about everything underneath. I replaced all 4 ball joints and did the front axle u-joints as well, the rust made that job extra fun. The body isn't too bad, although I have the classic rust at the rear fenders, cab corners and doorjambs. Once I work through the list of other issues, I'd like to take apart the front end and pull off the bed, take a wire wheel to that rust, then paint over it all with some POR-15 or similar.

 

[QuadDriver]

Originally Posted By: Execut1ve
I'll check it out, but I know for sure that the oil pan gasket and probably the rear main seal are leaking


change that 'probably' into something more firm - check out the back of the engine plate (ford puts a huge metal plate the shape of the back of the engine in there, it will have oil on the inside if and only if the rear main is leaking.)

for while the pan gasket is a lesson in dexterity, the rear main is a lot of ancillary work to get to a 5 minute job....

 

[QuadDriver]

Originally Posted By: Execut1ve
out of curiosity, why would 0w-xx or 5w-xx have any effect on anything at hot idle? I was under the impression that 0w-40 and 10w-40 have the same viscosity at running temps; the only difference is the 0w-40 is thinner at cold startup temps.



I would not bet my life, or engine on that. a 0 or 5 motor oil has a thinner base stock than a 10 and while the hot pumping visosity approaches each other, it does not equal it (not to mention the vi improvers for 40 will still be more viscous than 30 - its a double whammy).

With those big passages and not-too-tight clearances - especially in a broke in motor, by the time you get to mains 4/5 and rods 4/8 (on them big journals in the 351 makes it worse) - there may well be NO oil (some say chevy is just as bad on mains 1/2 and rods 1/3 but the inherent restriction in the oil passages leaves a little line pressure at the front of a worn motor.

but find this for yourself, T-tap the oil sender line and put on a real gauge and experiment. The hot idle oil pressure difference between grades *WILL* be staggering. not 'might', not 'could be', but WILL

(this is not a new phonomenon at all, many engines are dependant on grade for oil pressure. your light goes off at 7psi. so it takes a heck of a fail in which damage has long occured, to get mr light on. take the older vw 1.8 digi motor - if you used any less than 20-50 year round the light will come on below 1000rpm, or staying with ford - the 300-6 does best with 15-something, 10-40 in a pinch

 

[CATERHAM]

Originally Posted By: Execut1ve
Originally Posted By: QuadDriver

as a side note, dont put 0w or 5w anything in a old school ford engine especially the I6 unless you have a thing against bearings or watching the oil pressure drop to 5-10psi hot at idle.

out of curiosity, why would 0w-xx or 5w-xx have any effect on anything at hot idle? I was under the impression that 0w-40 and 10w-40 have the same viscosity at running temps; the only difference is the 0w-40 is thinner at cold startup temps.

Execut1ve, you are correct about 0W and 5W oils which is why you'll rarely see a manufacturer specify a 10W synthetic oil because it is redundant, a dino 10W-XX maybe but not a synthetic.
Also keep in mind that an engine has no idea what grade of oil you're running in it, all it knows is what the operational viscosity is at any given oil temperature. That's why the lightest 0W-20 oil you can get your hands on is thicker than optimum at start-up in every car and truck made even on the hottest summer day. In the winter your oil temp's may not get above 80C and a 20wt oil at 80C has approximately the same viscosity as a 40wt oil at 100C and to an engine there is no difference.

I do agree with QuadDriver on one point, and that is an engine's oil pressure is the bottom line. Having an accurate OP gauge makes fine tuning your oil selection very easy indeed.

 

[Execut1ve]

tell me more about this oil gauge. Does it replace the oil gauge in the instrument display? Is it installed permanently in the vehicle or just used during diagnostics then removed? And what oil pressure should I be shooting for?

 

[CATERHAM]

I don't think the F150 has an OP gauge that's standard fitment.
I don't know what the exact OP spec's are for your engine, but a good conservative bench mark is the 10psi/1,000rpm rule.

 

[QuadDriver]

Originally Posted By: Execut1ve
tell me more about this oil gauge. Does it replace the oil gauge in the instrument display? Is it installed permanently in the vehicle or just used during diagnostics then removed? And what oil pressure should I be shooting for?


ok, drivers side of engine, front, beind the acc bracket yet in front of how low the exh. manifold goes, is a tap point for the electric L-N O R M A L-H gauge, which most F series XL and above had (in fact I think it was std)

rip it out, put in a 1-1.5" 1/8th npt nipple and a 1/8x3 T, and in 1 end a 1/8 npt street elbow. put the ford thing back in and plumb in a sunpro (or whatever) mechanical gauge.

On the dash, if you do not have the dash mounted 4x4 switch, is a removable 4x6" panel that will take a 2" hole saw for the bezel.

route any wires or lines away from the exhaust mainfold.

I dont have any manuals in front of me, but I seem to recall the requirement is 35+psi at 2K rpm (my original 1990 ran 52 when I cut her up and the 'new' 1990 does 49-50 but I dont know how it was taken care of for its PO's 140K miles) - any chilton book will have the spec, mebbe someone reading has one handy

the 10psi/1Krpm is 'yunnicks rule of thumb' and works for SBC but its also based on a racing motor that is gonna STAY up there, if my chevy cars were cruising in OD at 15psi at 1500rpm on the highway, Id be adding parts....

 

[Execut1ve]

I have Chilton's in front of me but no luck finding the spec. I have found Chilton's to be deficient a couple times in my work on the truck, makes me wish I had gotten Haynes instead. Let me go down and verify what instrumentation is on the truck. You'll have to be more specific about the plumbing shorthand.

 

[QuadDriver]

Gimme an email or cell phone and I will snap a pic or two of my setup (90, 5.0, auto 4x4 with said gauge setup)

I have 2 editions of the chiltons for 87-91 f series (the total care one) and in chapter 2 are charts of torques, tolerances and specs....

 

[Execut1ve]

[email protected]

where in PA are you? you guys are probably enjoying this lovely ice that we are lol

I do have the dash mounted 4x4 switches but there is a little vacant panel to the left of them which I might be able to use. I do have the L - NORMAL - H style oil gauge in the instrument panel. Ch 2 of my Chilton's is engine electrical

 

[Execut1ve]

I grabbed the owner's manual while I was down, it confusingly recommends both 5w-30 and 10w-30 as "preferred" I can post a pic of the page if you like