Hi all,

New here, this is my first post. I just bought my first ford f150. It's a 92 4x4 with the 351w engine. I bought it knowing there was some issue with it and the passenger side head. The previous owner had the heads looked at by a local shop. They put heat sensors on them and told him the passenger side head was cracked because it heated up to 240 degrees and the driver side only heated up to 180 degrees. Are the 351w heads known to crack, is this normal? What are the signs of a cracked head? There are no coolant leaks or anything. They told him that these heads were known to crack in the valve guides area, is this correct? Thanks for any input.

Dean

 

i've never seen one crack. the 351w actually holds up better than any other engine i've ever seen or worked on IMO. but just like anything sh^t does happen. did the old owner know what happened exactly for it to crack?

 

I'd take it apart. Might just be a blown gasket. It probably over heated bad. They are good engines and they are plentiful in wrecking yards and available used and even rebuilt for cheap. I'm pretty sure I could find a rebuilt one slightly used for well under a grand.

 

I probably will take it apart, the truck only has 104k on it and I bought it from the original owner. I think you may be right about the overheating 'cause for some reason he decided he needed a 4-core radiator and had put that on it before selling it. I drove it 60 miles home and the heat guage was perfect the whole way home. I'm thinking it is either burnt or broken valve or bad head gasget too. I've had head gaskets blow before without getting water into anything. This I think is one of them.

 

what tranny does it have? and what did you pay for it? sounds like you got a pretty good deal

 

Maybe they put the heat senor "heatgun" ?? on the EGR passage ??

Does it blow water out throught the cap, compression check ??, water or oil leaking around head or on the ground or coming out the exhaust ??

If it runs and water level stay's the same and oil looks good and doesn't over heat it may not have a cracked head. I'd put a new thermostat and radiator cap on first.

One way to tell if it's been really over heated like no water in the block is to see if all the press in rocker arms studs are still even and one has'nt pulled out. Take a ruler and lay it across the top of the studs and check if they are still even.

 

I think I found the problem.........All cylinders on the passenger side had 125-130 psi on the compression check, except #2, it had 150. The spark plug was also gunked up while the other 3 were white, very white. I went ahead and removed the head and the piston top on # 2 was built up with a lot of carbon also.

Conclusion, based on what I have read is that the injector was bad causing it to run way rich and causing the power loss on that side. I read where the injectors can stay open and keep pouring gas into the cylinder. The previous owner said the truck just all of a sudden became a gas hog when the problem started. It all makes sense, I guess. The driver's side were all around 128 psi, even.

Thoughts on my findings?

Yes, got a good deal. 92 F150 4X4, 351W with the 4EOD, lock out hubs, super cab, 8' bed, newly rebuilt tranny (within 6 months at a cost of $1750) new AC pump at a cost of $550, new 4-core radiator ($350), new tires.......I got this truck for $900!

 

i'd say it ran lean with white plugs and since it overheated. but it may have ran rich in cyl.2. lean condition could cause the head to overheat.