I have a 2004 F150 FX4 3v 5.4L with auto transmission.

After numerous small problems in less than 5000 miles, now I have a new problem.

We had just put 5000+ miles on it pulling 5th wheel trailer. It was loaded and under a heavy load for all of it.

Now I have "Oil" in the Coolant reservoir. Not just a few drops but alot. Coolant is nearly black. It is Oil not transmission fluid.

Please note: NO water shows in the oil.

Pulled a few of the plugs and NO water or oil on the plugs either.

Any ideas of where to start?



Thanks

 

Hydrocarbon test the coolant. If exhaust gasses are present, its a head gasket....
No issues the whole trip? Till you got back and noticed the oil..
Where the hell did you go that was 5k miles in one trip pulling a trailer?

 

Off topic but, i didnt know it was ok to tow a 5th wheel with an f150...Am i wrong?

 

Depends on how big it is. smaller 5th wheels can be pulled by the newer f150's just fine. Today's f150 could probably out haul a mid 80's f250. Every year the competition forces them to get more and more out of these trucks.

 

I planned on getting a exhaust gas check kit from napa on monday morning.

Unfortunetly where I live there are NO auto parts stores that are open past on sunday, unless I want to drive 50+ miles.

After I test I plan on flushing complete system.

How do you go about pressure testing this system, since there is no access to radiator; only through the resevior which has no pressure?

Yes the truck ran flawless most of the trip...I threw a code on number #7 after 1880 miles but had an extra coil with; so a quick change and it ran fine. (from car wash; accidently sprayed to much water on drivers side engine compartment)

Yes, we put on a bunch of miles in a short time. We live in Northern Wisconsin and make deliveries all over the US.

Currently truck has 178,490 miles

Just an FYI: We pull a 25ft 5th wheel camper

 

Oh ok, ive never seen an f150 pulling any kind of 5th wheel before...Just didnt know they could.

 

My parents pull a 5th wheel with theyre 00 F150 sc 5.4L 4x4. Only about once or twice a year though.

 

The degas bottle (reservoir) certainly is under pressure. The cap that screws on is a pressure cap. A standard pressure tester works with an adapter.

 

Its a head gasket.

 

Not saying you're wrong but, how does oil pass a head gasket? I know water can from the coolant ports but where does the oil come from?

 

Possibly a bad head gasket but a good chance its the oil filter adapter gasket leaking. That gasket can go bad and the oil having higher pressure can enter the coolant system in that area. I would check it out first.