I have a 1998 f150 xlt, supercab, 4x4, 4.6 Romeo (truck production date is 12/97). And I have a oil leak.

Its on the drivers side of the engine. There is a nipple on the head, next to the firewall, directly above where the exhaust pipe and exhaust manifold meet. It looks to have some sort of bolt/flush stud inside the nipple. I have oil seeping by the bolt/stud and leaking onto my exhaust pipe. its a constant but slow drip.

Anyone know what this is or how to fix it? Is this a common problem? I can take a pic but cant find my camera at the moment. Any help/ advice is appreciated. Thanks!.

 

I looked at my '97 2WD 4.6L Windsor, trying to find what you were seeing, if it is on mine too. Not having any luck, need more precise location info.

Is this on the SIDE of the cylinder head, below the cam cover somewhere?

Or on the BACK of the cylinder head, inboard of the cam cover? It's real tough to try to get a mirror and light back there to look at the back surface of the head. After a few minutes of super hot garage and a cup of sweat, I gave up looking.

 

Heres a pic Torky2. This should help a lot.

On the right side, where the EGR tube ties onto the exhaust manifold. It looks like a bolt, in a nipple on the head of the engine. Its almost like its seeping by the bolt, or whatever that is.

 

I could not make head or tails of your pic, didn't know what angle and from where it was taken. I was trying to look from the topside down, using light and mirror. Man that was hard! I finally saw something... then I tried looking with my head down by the floor behind the driver side tire, looking UP through the wheel well.

And THEN I saw it, and now your pic makes sense.

On the side of the cylinder head, just below the bottom edge of the cam cover, all the way towards the rear, if you went any further rearward you would be off the back of the head. Above the exhaust manifold.

I see an Allen-head bolt or pipe plug? It is really hard for me to see detail at that distance, and I can't get any closer to see it. It definitely has an internal hex to it.

I looked in the '97 shop manual, I have a first printing, I could not find it. I thought maybe they would show it on cylinder head disassembly/reassembly, but no. I flipped through the engine disassembly, didn't see it there either.

Unless someone here has a later shop manual that explodes all the parts of the cylinder head, the other choice is to go to a Ford parts counter, and have them bring up a left cylinder head on the display, and look for the part. Once they locate the part on the drawing, with a few more keystrokes, they can look up the actual plug/whatever and tell you what it is. Be sure to tell them that you have a REP (Romeo Engine Plant), in case its different from a WEP (Windsor Engine Plant, which mine is).

If it is a pipe plug into an oil passage, I would probably order up a new plug from them, and start fresh with a nice new uncorroded one. Would be nice to know if any sort of sealer is to be used on it, and exactly what type of sealer.

 

You are correct on how to look to get the same view point as the pic. I haven't had time yet to truly check it out. I have to have my truck everyday and its been pouring rain here in SC. I think its some sort of plug. but I'm not sure what or what its purpose it.

I also didn't know if this was a leak point of the 4.6. I grew up on 302's and 351W's. And I've only had this truck for 4 months. So its a whole new animal to me.

Thank you for the help Torky2!

 

I tried to get the plug out today and it wouldn't come out. One of the dumbest things ford ever did was put a steel plug, in an aluminum head, in a oil passage way.

 

Finally got the plug out. For anyone in the future it is a 5mm Allen head plug. And pulling the inner finder out opens the area up pretty good. Hopefully I won't have any more oil leaks.

 

Glad you were able to remove it. I have never heard of this as a 4.6L leak point. Didn't even know it was there, don't think most people know about it either. So it must not be common.

Pipe plugs are not unusual in castings, when an innner passage has to be drilled in the casting, and such that it could not be reached from the inside with standard production tooling.

Just as an example, Ford carburetors for many years had a pipe plug up in front, to drill the passage from the cast inlet elbow that held the fuel filter, on into the needle and seat area. No way to drill that passage other than going through the front of the elbow from the outside, and then plugging the access hole.

The plug is steel, probably because an aluminum plug would not have the strength in such a small cross-section, and not round out the hex tool recess. And probably didn't use a press-in cup plug, due to the internal pressures. A pipe plug may leak, but they are very unlikely to blow out!

Did you get the pipe plug from a dealer? Did you find any info on sealant to use? Permatex #1, the hardening sealer comes to mind, I have used it on block core (cup type) plugs. And also block coolant drain plugs, including as used on the 4.6L.
But I don't recall if Permatex #1 can be used for hot oil or not.

 

I couldn't get the plug out before because I couldn't find my 5mm allan head socket. After finding it I tapped it onto the plug and it came out pretty easy, it wasn't tight. Normally I have hydraulic sealer by permatex around but I was out so I used pipe tape.

I ended up using the same plug. It was Saturday and late, so the dealer ship was closed, and the threads were good and I can get it out if I have to with the 5mm allan head. So far so good. no leaks.