Ok i need some help here.. i have a 94 f150 with a 5 litre with about 260,000k's on it.. ever since i baught it 6 months ago and its bin leaking.. thought nothing of it till i seen how much its leaking.. theres about a 5 inch round puddle under my truck every morning.. so i did my own oil change put a brand new plug in with a new plastic washer.. didn't work.. so i put teflon tape on it. still leaks... so i went back to the parts store.. told the guy it aint leaking.. gave me another plug for free with a copper washer and a thin copper washer with a rubber o ring built into it.. so i tried that one first with teflon again.. still leaks the same amount.. so i put in the copper one with lots of teflon this time.. still leaking rite now!!! im so lost.. i hate oil leaks.. wut else can i try??? and trust me the plug is tight.. i was just making sure i don't stripe it.. n e ides plz??? maybe the surface is warped?? should i grind it down?? sand it?? thanx

 

You and I are having identical problems. I just rebuilt the engine too. Take a little closer look. Look to see if it's leaking from the back of the oil pan... down to the plug... and off the plug onto the ground. I can't tell if its the rear main or if it's the back oil pan seal. I'm too lazy to pull the engine to redo that gasket though!

 

Also a small crack in the pan itself can do this.

 

DO NOT PUT "TEFLON TAPE" ON THE PLUG! This can get into the oil system and do MAJOR DAMAGE to the bearings & surfaces!

Sam

 

Oversized drain plugs can be bought from Ford and every auto parts store. There are at least two sizes. Start with the smallest one first. It will cut its own thread into the oil pan.

 

You may wanna be careful with cutting new threads in. These metal shavings can destroy an oil pump and/or bearings. Even if you were to put grease on the bolt as you cut the threads to catch the shavings.....the grease can plug oil ports and cut the oil supply to part/parts of the engine.

Sam

 

Correct me if I'm wrong, but isn't there an oil filter between the oil in the pan and the bearings?

 

The sceen dosn't keep everyting out. If the plug tightens up fine . Just go to auto parts store and get new seal washer for plug they are cheep. I replace them alot on the vehicals I service.. But look close right by plug is where the pan likes to rust through. Please post and good luck

 

Screen -> pump -> filter -> bearings

Right?

The bearings aren't going to be damaged by teflon tape on the drain plug, unless there gets enough in the pickup screen to starve the engine of oil.

 

I don't know that you can put a larger plug on it...if you look on the inside of the pan where the plug hole is you'll see that the plug doesn't just screw into the pan, it has some extra metal there and I don't know that you can just tap that as an oversized hole...there isn't much material there for it as I remember it.

 

thanx for all the replys guys, as for the teflon tape i did try to make sure i put it near the head of the bolt so it actually stays on the threads.. but u do have a good point about getting it into the oil system. first off i no its not leaking from the rear main seal... and theres no crack in the pain.. i clean it off every so often or when i changed the plug with different washers to see if it leaks.. its coming from the plug for sure. An over size plug mite be another idea i can try, but i'll make sure i run oil either thro it at the same time flush it of some sort to make sure theres no metal shavings.. i'll talk to my local parts store about that over size plug. other then that i guess those are my only options.. unless i replace the whole oil pan?

 

The over size self-taping plugs (thread repair plugs) are for striped threads, if your threads are not striped you do not need one.

The drain plug seals with a washer not the threads, it is not a pipe plug with tapered threads so Teflon tape or pipe dope will not work either.

If it does not seal with a new washer and the oil is not coming from the rear seal, pan gasket, rocker cover gasket, crack in the pan or rust hole then the plug has been hit and the mating surface is not true. The pan will have to come off and be replaced.

Do not use rubber washers as oil will eat rubber very fast and will leak, use neoprene, plastic, or copper washers only.

Also EPNCSU2006 is right about the filtering system and Teflon tape will not harm anything in there either.

 

TRAV460,
My 88 351 came with a plug problem. Guy had a rubber expansion plug in it. When I changed the oil I thought I'd use an oversize repair plug but upon further review found the thread inside was cracked so no way to cut new threads. Had to go to I believe a 5/8 rubber plug instead of the 1/2". Get under there with the plug out and shine a light in there--or run your finger around the inside. Seems the threads must be welded in around the thin pan. Owing to some of the gargantuans doing oil changes at the dealer or quick lubes it's a wonder more threads aren't stripped. Wifes car came back from the dealer with the plug so tight I had to use a cheater bar to get it loose.
You may want to try the rubber expansion plug route. A pain when changing oil but about $4 so not expensive. Seems to work OK leak wise.
Good luck
Mike