Hello to all. I'm looking at buying a 68 F100 with a mid 70's model 302 (not sure of the exact year) I went and drove it a few weeks ago and noticed a coolant leak from the intake manifold. The owner said it had been doing that for a while, and that he just made sure the coolant was always topped off. After further inspection of the truck I could find few major flaws, so I was considering making an offer right then. Until, that is, the owner told me that it used a quart of oil every 1300 miles or so. I decided to scratch that one off my list and continue my search for a truck. I decided to call him back today to take another look at it (the first time it was late in the day and got dark while I was looking it over). I want to get a look at it in the daylight. It's an old truck for sure, but not too bad for its age. My question is this...Could an intake manifold coolant leak cause excessive oil consumption in a 302? From what i could see, as well as going on the word of the owner, there were no oil leaks apparent. So its the coolant leak in the intake a possibility for it to burn oil? there was no smoke at all from the tailpipe. Thanks to all in advance

 

Also I should mention it was leaking externally, not internally. The engine oil looked good.

 

3 strikes:

--mid '70s were the worst, lowest power engines

--coolant leak might be a crack or stripped fitting, very possible on the 302 manifold.

--oil use is probably the neoprene umbrella valve seals all in pieces under the valve covers, or rings, or both.

On the plus side, the sbf is one of the easiest engines to rebuild, and you could have 250 horse without a lot of effort.

Depends on your budget and tolerence for this kind of nonsense. If you want a turn key driver, pass on that one imo. Good luck in your search.


ALSO, what trans is in that truck?

 

it's got a c4 trans. I'm gonna copy and paste part of his ad. that'll give you some more info on the engine itself.....

5.0 rollercam V-8 (302) with factory Ford electronic ignition and Edelbrock engine package (alum intake, 4 barrell, valve covers, air cleaner, etc), factory shorty headers, dual exhausts, all new electrics (ignition switch, turn signal, fuel tank sending unit, etc), everything works,

so it's not all stock intake etc...

 

OK, back to two strikes, as it sounds like it may have been a Mustang motor or similar. Roller? Those weren't '70s motors, so perhaps it was upgraded. But it sounds like it needs some TLC if not a major overhaul.

With the leak and oil consumption, imo it should be considered as needing a complete overhaul and you should pay as little as possible. It may not, but you can't know without opening it up. Sellers and manufacturers will tell you a quart in 1300 miles isn't a problem. That's because they want you to buy their oil burner or don't want to pony up for expensive repairs under warranty. Valve seals smoke on hot restarts and when you have vacuum spikes like lifting the throttle to shift--something you wouldn't do with an automatic.

 

Thank you for the advice, I really appreciate it. In your opinion would taking the heads off and having them rebuilt solve the issue? Or, given what you've read that I've posted, do you think it would still need completely overhauled? Also, assuming the owner would let me...could I take the valve covers off and see anything that would give me a clue as to the condition of the valve seals? Thanks again.

 

Pulling the valve covers would reveal the condition of the seals. If they are not the neoprene jobs, then the oil consumption would be via worn rings. Even if they are neoprene and in pieces, there is no guarantee that the rings aren't bad too.

Valve seals can be replaced with the heads on, although it is no joy to work over the fenders of an F100 to do so.....

 

If you can pull the valve covers,look in the valve springs for broken or damaged seals.There might be parts of the seals laying around the spring/rocker area.Check the rear of the exhaust system for oil residue.If you can pull some spark plugs,do it.If oil is leaking past the rings,you'll know it from checking the plugs.If possible take the truck for a short drive.Let it sit for 10-15 minutes and start it up.If it blows smoke on start up,it's likely the valve seals.Worn valve guides will let oil into the cylinder while the engine is running.But they might also cause smoke on start up.I think the 68-72 Ford trucks are the sharpest looking trucks.I'd love to find one(4x4) in good shape.302's are easy and cheap to rebuild,as another Poster said.