ye olde oil leak

[PatBuckley]

Steam clean the back of the engine and bell housing area, let it dry, drive it, black light it.

If the leak is not obvious, pull the trans and reseal the galley plugs as well as checking the front seal of the trans for leakage.

Are you using synthetic oil?

If you are, stop.

Good luck.

[Naumoff]

What Pat says is a good thing to do.
If you have a leak from the back of the intake manifold and or valvecovers it can run down the back of the engine and show up at the front of the bell housing.

What kind of bellhousing is it?

[double ugly]

It's a lakewood housing. We did the black light test and found no evidence of a leak except on the flat front of the bellhousing.
John

[Naumoff]

Yeah.
And that engine plate goes right up to the back of the intake manifold.
You can't see the back of the manifold or put your fingers on it to check if the manifold is leaking.
Take a small wad of cotton on a skinny stick and swab the small space between the bellhousing and the manifold.
A throat culture swab would be perfect.

[double ugly]

I'll give that a try.
John

[c6ae]

If you decide you have to remove the flywheel to find the leak, don’t overlook the cam plug. I have found this to be a more common leak than the other smaller gallery plugs. The cam plug is installed with the cup facing in, unlike a water jacket core plug ( and occasionally installed incorrectly!)

[double ugly]

If we have to go that far, I'll make sure it's in correctly. Do you have the screw in or press fit plugs?
Thanks, John

[c6ae]

I have several FE’s, only the 390 in my old pick-up has press in plugs. I have repaired/built a number of them over the years and in my experience the press in gallery plugs are not as often a problem as the cam plug. It was common practice for rebuild shops to slather some silicone sealant or some other goop all around the cam plug because they did not trust it. (I have seen several of them installed backwards and if this is the case the cam can bump it loose) On assembly I use just a bit of red Loctite on the rim of the plug, not smearing stuff around the plug.
I recently repaired an FT 391 (same oil system) that the cam plug had fallen out of… gone. In the search to pinpoint the leak, which was significant, 1-quart/15 minutes, I pressurized the system to 75 psi using a drill and the darn thing would not leak. This engine had to be running to leak. This test pretty much ruled out the gallery plugs. I suspect that a gallery plug would leak under pressure if it were running or not but the cam is effectively closing the oil passage on the cam bearing when it is not running so the missing cam plug did not leak!
You can make this test, to help make a determination about the gallery plugs. Wipe every thing down in the area under suspicion and bring the engine up to temperature then pressurize the oil system with a drill motor and watch for leaks. A gallery plug will leak.

[Jac Mac]

John,

If/when you pull the trans,flywheel etc spray some of the white crack test developer on the suspect area (clean & dry first) then run up oil pressure with drill & check for leaks. If there is still no indication refit flywheel and an old auto trans or Ford OE bellhousing with starter and actually run motor for 15 minutes approx[ Set bellhousing on block of wood and make sure earth strap from frame to engine block is connected]. Then these parts can be quickly removed to check source of leak after shutdown. The developer will wipe off with wet/damp cloth.

Jac Mac

[Naumoff]

DU,
Is it easier to pull the engine and trans out together or do you have to pull the interior anyway? Pull the engine and replace all the gaskets. Might be quicker and easier.

In my opinion if the car has to make a run before the oil leak shows up it is due to sloshing around the areas were the oil will collect on its way back to the pan.

[double ugly]

Pulling the engine with the transmission attached is real tricky, I think. To get the engine out the radiator and pusher fans need to come out in order to get the hood off. Much easier to take the seats out and remove the tunnel and lift the tranny out etc.
John

[Jac Mac]

John , here is another tip you may want to try before you pull the trans, seal off your breathers etc on the rocker covers. apply an old reversed vacuum cleaner or low pressure air source to the oil filler cap. Remove the dip stick to allow most of the pressure to escape and apply some dishwash/ liquid soap & water mix to any suspect areas like the valley gaskets etc, any leaks should show as bubbles. Do not use excessive pressure or you may create a few more leaks.

Jac Mac

[easystep]

I know Keith Craft on his FE builds machines all the blocks he does for a single-piece rear main seal. If you are going to pull your engine, you may want to think about this. It's supposed to cut down on leaks from this area considerably.

[Carnut427]

Originally Posted by easystep

I know Keith Craft on his FE builds machines all the blocks he does for a single-piece rear main seal. If you are going to pull your engine, you may want to think about this. It's supposed to cut down on leaks from this area considerably.

You must be thinking of a smallblock...the later models ('85 or so up) come with a one-piece rear seal, which takes a modified crank. Can't be done on an FE.

Dan

[double ugly]

I've decided to pull the intake manifold and replace the gaskets along with the valve cover gaskets. This will take a lot less time than removing the interior to get the tranny etc. out to check the galley plugs. (many people have told me that it is fairly rare for them to leak the quantity required to cause my problem). I've already wasted the money to have the rear main replaced so I've decided this is the next step. The gaskets are cork not a silicone smear but it seems like a logical next step. I did notice that the left and right sides at the rear of the intake gasket are a translusent grey/black. This may indicate a leak. I'm really surprised that the black light didn't show any thing there though. Again thanks for all your advice as the saga continues.
John

[double ugly]

Well, I went to Checkers and bought Felpro gaskets (20 mile round trip) and by the time I got home the oil and water temps had reached normal temps of 65-70 degrees. I put it on the Quik Lift and a couple hours later looked under the car. The oil spot was the size of a quarter. (can live with that) I figured that maybe the mechanic was right and it was oil residue in the bellhousing working it's way out from a previous faulty rear main. I checked again an hour later and no change in the size. After the baseball game I went out and found the size had increased to half the size of a dollar bill. Crap. Look's like I'll replace the intake gasket but I really have my doubts that it will change anything. Using a Q-tip I found no wetness behind the intake manifold.
John

[vettestr]

John,
I know you are very capable to replace intake gaskets. I have also replaced a ton of them and have been taught a few tricks over the years. They are simple things like taking a center punch lightly across the block surface about every 1/8 inch apart where the end gaskets are placed. I also do this on the mating surface of the intake manifold. Just randomly punching across the surface will leave a surface that grabs the gasket too reduce tendancy to be squeezed out. The sealant makes the gasket slipery to agrivate things even more. I have better luck with just RTV replacing the cork or rubber gaskets here but only if applied in 3 stages to allow/adjust for shrinkage of a finished 1/4 inch thick line of RTV. This light surface prep will not hurt the block or manifold for future gasket replacements and so on even on a rare or charished manifold if done properly you have little to loose trying this. There is a ritual I follow in addition but would make for a long thread. I am local to you so give me a call at 602 402 8504 if you want to hear my tricks, you can pick and choose the ones that make sense to you. You will beat this so hang in there. Jeff C

[pmfranke]

I have a 351 and it seems like i have the same problem . i have no leaks from the top , two piece main has only 500 miles on it . two dime size drips after a hot lap. Are our cars still considered BRITISH ? My Norton 850 in 34 years has never stoped leaking.ARG peter

[Naumoff]

Originally Posted by double ugly

Well, I went to Checkers and bought Felpro gaskets (20 mile round trip) and by the time I got home the oil and water temps had reached normal temps of 65-70 degrees. I put it on the Quik Lift and a couple hours later looked under the car. The oil spot was the size of a quarter. (can live with that) I figured that maybe the mechanic was right and it was oil residue in the bellhousing working it's way out from a previous faulty rear main. I checked again an hour later and no change in the size. After the baseball game I went out and found the size had increased to half the size of a dollar bill. Crap. Look's like I'll replace the intake gasket but I really have my doubts that it will change anything. Using a Q-tip I found no wetness behind the intake manifold.
John

I am going to do the same thing in a month or two.
Just make sure all your surfaces are clean of all oil and dry. After putting it back together let all adhesives set overnight before firing up the engine.
Good luck

[edwhite7]

Is it a Shelby Block? If so the drain back holes in the rear main bearing cap are not big enough. The cap has three holes that go from the crank to a milled slot. The holes are too small and the milled slot is often filled with your pan gasket. If you have a windage tray check that the tray and the gaskets are not obstructing the oil return. I fought this problem for years before I opened the holes to a slot and deepened the milled passage. I also notched my windage tray to help the oil return. If you have a Shelby block, drop the pan and look at the rear main. It will suddenly be obvious.