Hey folks. I'm looking at a 99 F150 4.6 with 135K on the clock from a local seller. I had it in the local Ford dealer for a "used car inspection" yesterday and they say BOTH head gaskets are leaking oil. No visible oil in the water or water in the oil...just a slight bit of seepage from the head gaskets. The tech said it's DEFINITELY NOT from the valve cover gaskets.
Yes, it's POSSIBLE that both head gaskets are seeping...but IMO, rather unusual.

Leaky valve cover gaskets I can live with...leaky head gaskets are more than I want to deal with. (dealer says $2500+ to fix...IF the heads aren't warped...again, not likely)

My neighbor, a retired Ford mechanic with over 40 years experience says it's very unlikely and that the tech at the dealership was either too lazy to track down the actual source of the oil...or that they're just trying to CYA.

Otherwise, the truck is in very nice condition with only a few very minor things wrong.
FWIW, this is in the Puget Sound region of Western Washington.


Any thoughts or ideas?

 

Its not uncommon for the modular engine to seap oil from the head gaskets. Usually if the starter is oil soaked the head gaskets are leaking. Look at the starter. If its covered with oil the tech at the dealer got it right. I havent ever seen the 4.6 have that issue. More common with the 5.4

 

Thanks. After doing a bit more research, it does seem like this is a fairly common problem.


The seller (who's a construction testing engineer) says he found some info on the internet (if it's on the internet is MUST be true :P ) that says some machine Ford used during engine assembly was known for leaving a small sliver of metal between the block and head gasket...
While I SUPPOSE that might be true... it just seems to be a little bit...



edit...it looks like that might be true...

http://www.ford-trucks.com/tsb/fullt...p?tsb=01-21-10

 

it is true.

 

its really not that expensive of a repair-if you do it yourself.

 

Well there was a short period of time that there was a problem with aluminum chips. The robots that installed the cyl heads at the factory were broaching the mating area of the cyl head to block deck alignment dowel and dowel pocket. This was a short window and most of these were infant failures meaning they started leaking within 3000 miles. The small chip would drop down onto the head gasket and create a high spot that could allow oil to leak. The rightside cyl head has the high pressure oil supply passage very close to the rear of that cyl head so it is more likely to leak oil externally down the back of the head and eventually down onto the starter. However a overheated engine will leak there as well..The leftside cyl head has the oil passage at the front of the block (remember these heads are machined the same but are reversed during assembly) So if the condition exists on the leftside cyl head it will leak behind the front cover and down into the oil pan and never show oil externally and therefore not create any concern.
The only other source of oil that will leak at the side of the engine is the oil drainback holes or the cam covers.. usually if you get oil from a drain back you will also get coolant leaking as well. I doubt that your engine has the aluminum chip issue again it was determined to be an infant failure.We removed hundreds of head gaskets before we finally found the cause of those oil leaks, it just so happened that there was a supplier head gasket design change at the same time so we thought it was a gasket coating issue causing/allowing the leaks. The aluminum chip looked just like a small fingernail clipping because it was from the cyl head alignment hole radius and was initially thought to be just debris that was generated when the head was manually removed.

 

I suspect that with the modular engines, it would probably be more than I could have tackled in my youth...and nowadays, I'm just too busted up to do any of that. I can't even do my own oil changes anymore... (sucks getting old)

Anyway, I passed on the truck. The guy didn't want to budge on his price, and he was already on the high side of its value.

Thanks for all the input.