I have a very good friend with a 1997 or 1998 F-150 4.6L Super Cab 4x4.

He has had the truck for several years, but only here lately has he noticed that it's using a little oil. The truck only has a little over 150k. He says he has to add a quart of oil every 2k miles or so.

It doesn't smoke, nor leak... But, the coolant is a brownish color, and I'm about to bet that it's the head gasket. It kinda smells... Oily, too.

How do we find out what it could be FOR SURE?

Nightrain

 

Leakdown test, look for coolant in the oil and oil in the coolant, look at all the plugs and see how they are burning.

 

I know that there's not any water going into the oil. Oil is leaving the motor, in some form or fashion.

I've never seen a Ford use any oil with only 142,000 miles on it, but I guess it's possible.

I just thought that it was concidental that it had brown coolant, but then again... It could just need changing.

I'm going to flush it for him sometime this week, and see what goes from there...

Thanks for your input!

Nightrain

 

The only way to "confirm" a leaky gasket is to remove it and inspect it.

Based on your limited description, I wouldn't yet suspect a HG fault.

Probably just a cooling system and engine that has not been maintained and now is starting its downhill slide.

Steve

 

You can run a compresson test..and see if any cylanders are lower (psi wise)..I have seen motors suffer at 150.000 running pinsoil...you might try gtx high milage oil and see what happens...your are right change the coolant..good luck bill

 

Okay, here's the low-down...

I just now finished flushing the complete cooling system, and this is what prevailed--

With the engine running, I hooked up my "homemade" cooling system flusher, and began the task at hand. When the thermostat finally opened, alot of dark, black, "oily" crud came first. Following the "oily" crud, some dark, brown, possibly "milky" antifreeze began to flow out of the hose. Then, shortly after that, the new antifreeze started running out.

Folks, it's looking like it's not anything BUT the head gasket(s).

Once again, the symptoms--

-Losing oil (Possibly one quart every oil change: Not leaking out)
-Dark, black, "oily" antifreeze drained out of truck's cooling system

This has all really suprised me... The truck runs as smooth as anything. Without looking in the coolant tub, you wouldn't know it had a problem.

I believe that the head gasket is busted on a water jacket.

And then again, it COULD possibly be an intake gasket.

At this point, I'm lost.

BTW, under the hood on the radiator support, there is a sticker from an auto service place that states the cooling system and transmission were serviced when the truck had 104,000 miles on it. It's got about 45,000 miles on that coolant service.

Thanks again for any suggestions!

Nightrain

 

Its a good idea to change the coolant yearly anyway..durty coolant does not mean you have a problem..as for the oil leak that much can do down the valve gides with out much notice..if the head gasket was bad most the time you have a overheating problem just run it and see..did you use a coolant flush or just water.with plain water theres probly still som trash in your cooling system..so if it get durty anytime soon you will know why...good luck bill

 

I flushed it through with new coolant.

I've just told him to drive it for another oil change or so and see what happens.

Hopefully everything will turn out okay.

Thanks for the help, ya'll!

Nightrain

 

With that additional data, I'd now lean more toward your original suspicion.....

A compression check on the engine and a pressure test of the cooling system would be the next diagnostic tests....

Steve

 

Might want to try a flourescent dye check on the cooling system.

 

I had the same problems with my expedition. Its a 99 with 4.6. It was running fine but, it used oil. No smoke, no oil in the coolant, and no smoke on start up. I kept watching it. My problem was the #3 cylinder. I had the heads done about 3 years ago my truck was one of the many with the manufacture defect in the right hand head. It had an external oil leak that poped up around 60000 miles. I had the heads milled to remove the defect three angle valve job the works. At about 125000 miles my truck laid down. I was only getting about 35psi in the #3 if I added a little oil it would come up. So I picked up a remanufactured 4.6 from Ford and changed engines over one weekend. I don't want to be the bearer of bad news but it could be more than you think I learned the hard and expensive way.

 

Thanks for your post 1helmet, and welcome to FTE!

I've pretty well decided that it is the head gasket that's going down in his 4.6L. He's debating on a remanufactured engine purchase, and us installing it in the near future.

How hard are these motors to remove and reinstall, though? They look like a PITA...

Thanks again for your info!

Nightrain

 

Thanks for the welcome

They are a pain. What I found was the most difficult was how far back everything sits in the engine compartment. Almost half the engine is under the fire wall. Other than that its just moving all the components from one to the other.

 

Yeah, the distance it sits under the cowl is what worried me, also.

There's a thread going in the 97-2003 F-150 forum right now that has to do with engine removal. They suggest removing the front bumper, grill, radiator support, etc., and pulling the motor out of the front.

That's sounds like a winner to me, as long as the truck isn't as big of a pain to take apart as it is to pull the motor out of.

Hopefully we've got until at least this spring before we worry about it, though.

Also, any additional information or tips that you have about pulling the motor would be a great help!

Thanks again!

Nightrain

 

I removed the radiator and the fan along with the rest of the accessories to give me room in the front. I pulled the intake off the top. I connected a chain across the top and used a piece of plastic to protect the fire wall from the chain. I raised the engine up enough to clear the motor mounts pulled the engine forward to clear the firewall in the rear and straight up and out.