Hi,

I'm a new member to this forum and hope to find some help with a 66 F100.
It has a 352ci engine with a manual 4spd, manual steering and brakes.

I bought the 66 in January for my son. Something cool that we could work on together. It looks great but needs some mechanical help. This is good cause I don't know body work, but have been working on my own cars since I was a kid.

So here is the issue I'm having with the truck. It has low oil pressure. The truck has the stock oil light and oil gauge. Both indicate low pressure when the truck is warm. Also, the engine makes noise when idling and sometime when there is light or no load on it.

I replaced the oil pump with a new Mellings M57, but no love.
The previous owner states the only major work done on the truck was rebuilt heads from a 390ci.
The truck has a remote oil filter setup.

Also, the oil pan gasket leaks terribly. I followed the torque specs for the pan but it looks like it was too much for the Felpro cork gasket and Permatex High Tack sealer I used.
I wanted to hear if there are "best" methods to a ford pan gasket. Type of gasket most people use, any process that works best.

We have some old Pontiacs and I know those fairly well. Never had problems with the Felpro/High Tack sealer combo.

Well, thanks in advance for any help. If this forum is anything like the Pontiac forum I use, I will learn a ton from you guys.

 

I suppose since you removed the pan to install the oil pump you have your self to blame for the leaks. Probably need to pull it again, and block it, meaning making sure it is flat all the way around, then reinstall it. Fresh or old over tightening will cause the leaks.

As for the oil pressure, you just have a high mile 352, the crank bearings are pretty worn giving you a low pressure.

Now after having said that, keeping oil in a FE is more important and how high the pressure is. It can run years on low pressure as long as you keep plenty of oil in it.


You'll probably want to rebuild or replace it in the future, but it's not priority yet.



John

 

People tend to over tighten the pan bolts causing the area around the bolt holes to flare outwards.

Remove the pan, set it on a flat surface...you will see it sitting on 19 pedastals.

 

Solving an over tighting issue is the easy part. On the pan gasket, I was more interested in the experts opinions on what they recommend from a gasket and sealer perspective.

And more importanantly, any input on the low oil pressure.

Would a high volume oil pump help at all?
What about running a thicker oil like a straight 30W?

 

First off ditch the remote filter setup. Did you try a mechanical oil pressure gauge to see what actual pressure is?

If you have already replaced the pump and low oil pressure its an indication of brg clearance. When you remove the pan again pull the rear main and look at bearing and crank. When the brgs get loose it can also cause rear oil leaks with the rear main.

On the noise do you think its a rod brg going out? Another indication of possible brg failure. I just pulled a 352 pan off recently that had never been off and the crank and bearings look pretty good after 45yrs. Oil pressure was 45psi @ a bit higher rpm and down to around 20psi at idle.

As far as sealing them up I use the Ford gasket cement for gasket to block then put a very thin film of "the Right Stuff" sealer gasket to pan simply do not get leaks. In the past I have used the Ford gasket cement both sides and did not get leaks.

I normally go just a few inch pounds on initial torque then wait for the sealant to set up then do the final torque which should be 10-12. If gasket is really squishing out its too tight. Are you using a cork or other pan gasket?

110-120 inch pounds is usually adequate.

edit add: are you sure its the pan or the rear main side seals or not leaking past the caps?

Did you offset the rear main seal, put sealant across the main cap-block? What brand seal and gasket did you buy? Some of the side seals expand upon contact with oil, did you oil or soak them. Kind of tricky until you get the hang of installing that main cap. Explain how you installed the rear main seal and main cap side seals and pins

A cheap oil filter like a PH8A Fram can also give you lower oil pressure than a good filter like the FL1A or the FL1HP Motorcraft. The remote filter can also give lower oil pressure

 

Ditch the remote filter setup you have a a pressure loss right there! Make sure you are using the correct oil like 15w40 dual rated diesel motor oil like shell rotella t or something close to that. The pan gasket well ditch it. I never use a gasket on that and never have. I make sure both surfaces are clean I use brake parts cleaner for this. I wipe it down one last time with a clean towel then apply a 1/4'' bead of grey RTV silicone the and make sure to circle around all the bolt holes. Then I had tighten all the bolts and torque them to 5ft pounds after 45 mins then apply final torque setting after 2 hours. It works for a leak free seal most automakers have been doing this for years as RTV has become common practice for most items.

 

Get outta here with that "dual rated diesel motor oil like shell rotella t " BS, any brand 10w30 or 10W40 is good enough for these old trucks. Has been for 50 years.

If you want to run it fine but calling it correct is plain wrong.

I have well over 1,000,000 on vehicles that I have owned and maintained, I think I have a clue.






John

 

John,

I suggested the dual rated oil for the added ZDDP it is required on all new cams for break in and warranty comp cams as do most grinders requires the use of it or their additive. The newer SM oils do not have it. I suggested it as a way for the poster to avoid the overly pricey 14.00 oil additive for oil that will be drained in a few hundred miles. Just trying to help.

 

Thanks for the input guys.

• I will ditch the remote filter.
• I will not ovet tighten pan bolts.

Questions:

1. Will a high volume oil pump help?
2. will a thicker straight 30w help? or is the multi weight oil better?
3. any more input on gasket w/sealer vs. just RTV?

Thanks again!

 

The truck is over 40 years old. What is the engine condition?

If the engine is worn out (low oil pressure is a good indication), spending bucks for a high volume oil pump, changing engine oils (which may do more harm than good at this stage of the game), is a waste of money.

People use high detergent oil in old engines (do you know what type of oil it has now?). This loosens up all the crap, which then circulates throughout the engine and can plug up the oil holes.

 

The specs indicate 'normal' oil pressure is 35-55psi at 2000 RPM.

My concern is that the oil light sender is calibrated at 3-8 psi. At least that is what the one carried by NAPA is. If it comes on, as you have noted, that to me it would be an indication of unacceptably low oil pressure.

Still, it could be a bad or plugged sender. The gauge sender has only a pin hole for the oil to register pressure. The light sender has a larger opening, but not much more than a normal pencil lead.

 

Have you tried a oil pressure gauge? I installed one on my 66 F100, I do not like the idiot lights, my 352 has 40 lbs at cold idle(30wt). This will tell you if the oil pressure is low or not, what type of oil did you put in it after the oil pump replacement?

Good luck!

 

The truck has the stock oil pressure gauge and idiot lite.
The both report the same thing.
I have not installed an aftermarket gauge yet.
The oil is 15w40.
Filter is a Wix.

I know it's a tired engine and probably in need of a refresh, but was looking to put that off if reasonable "band-aid" would work for a while.

 

I have a remote oil filter with no noticeable pressure drops. An Autometer oil pressure gauge is in use, so it would be hard to tell if there were a 2 psi difference should the remote be taken out. Where does the pressure drop occur in a remote setup? Friction inside the 1/2 inch lines? Havent seen any such thing. Regular output oil pump on 10/30 yields 55 psi hot cruise, 22-25 psi hot idle. I wouldnt recommend anyone using a remote unless they had to, but certainly wouldnt agree with the implication that there would be a significant pressure loss.

 

Just try driving the darn thing. What you described is very usual for a high mileage FE, a fresh rebuild with oil passage mods, no.




John