TERZI

Hello all..I have a 99' F-150, with a 4.2, 220k on it..found coolant getting into oil. Was running smooth, no smoke before I noticed. My first thought was possible leak in gasket where coolant goes though timing cover. Seen somewhere it might be a freeze plug also, in engine under timing cover. Took it all apart, and from what I can see is 2 hex plugs at top, behind chain. My question is could these plugs be leaking, and is there more plugs behind timing chain. Figured I would ask you guys before I go through the pain of removing chain/sprockets. While it's all torn apart, would like to get every possible cause repaired, as you all know..any input would be greatly appreciated!!

w0lvez

If there is no crack on the Lower Intake Manifold and Engine block the only place where coolant can mix to oil is thru this 2 holes going to the water pump.

screamineagle

A freeze plug has nothing to do with oil. Most likely a cracked intake or warped/cracked head or faulty gaskets.

joe mcmillan

As you removed the head and head gasket, you should have been able to observe the integrity of the gasket and seal. You should still be able to inspect these areas for a possible water leak. If it is there, it will be visible.
Now that you have the engine partially dismantled, you should consider doing a major overhaul. Have the block cleaned and magnafluxed, take the head in for full service, check the bore dimensions. Do as much of the work yourself as you have tools and knowledge to do. You will end up with a like new engine and some great experience.

w0lvez

The Hex Plugs you are refering to are "Oil" Plugs.

You need to remove the Cam Position Synchronizer before removing the timing cover. Don't forget to remove one hex bolt holding the the timing cover. You can remove water pump stud using two nuts.

guyina4x4

4.2, very well known for intake manifold gaskets leaking.lets water into cylinders, leaks past rings into oil.

I've fixed a couple of them for less than $50 each, takes about an afternoon to do.

TERZI

Thank you guys for all the great info, I really appreciate it..since I have several ruptured disks in back, it's taking awhile to get it everything done as quick as I used to..another question I have is what is the best thing I can put into oil to clean out all the gunkie old coolant/oil mixture though out the engine?

Ford Fan#1

every oil additive is snakeoil. Best thing to do is change the oil early. I'm sure others have different opinions but that is mine. Goodluck

guyina4x4

yep

Frank_Ford

The most common cause of that for the 4.2 six cylinder would be at the intake manifold.