So, I own an 89 F150 5.8L.

I recently put $1700 into the damn thing. That included:
Brake Flush
Valve Cover replacement
New exhaust
Upper intake manifold gasket replacement
Thermostat/gasket replacement.

I did all this because this is my work truck, and I can't have the truck leaking on my customers property. Now its leaking worse than before.

I am getting a drip from the back of the engine. Even the little "pockets" where coolant could puddle, it does puddle. Like at the very back of the engine on the driver side, right around where the lower intake manifold is. There is a pocket that fills up after a 2 minute drive.

Is this a common issue on this truck? I am pretty mechanically inclined but I don't know this engine very well. Is a lower intake manifold easy to replace?

Have any ideas on what could be leaking so bad? It looks like there is oil in the coolant on the ground as well.

 

Could be a head gasket, freeze plug, gonkulator, ect... Little bit hard to troubleshoot this one over the internet. You can buy UV leak detector dye and use a blacklight to pinpoint leaks easier while the motor is running.

Adrianspeeder

 

So I had a friend of mine take a look at it. It's the lower intake manifold gasket......

So does anyone have a write up on how to replace this? I have a haynes manual. Is that my best bet? Anything special I need to be aware of?

 

When pulling off the intake plenum, the center bolt down in the runners is a harder one to get to. I use a 1/4" drive 1/4" inch socket with a screw driver torq bit taped in place because it is too narrow for my regular torq bit set to get down in.

Adrianspeeder

 

Anyone have a picture of the lower intake manifold? I cant come around to actually thinking there is one. I thought it was just the intake manifold and that's it

 

Nope, it exists just like on an ole carb'ed motor, except has 8 intake runners to match the cast aluminum upper intake manifold contraption on top.

Adrianspeeder