Hello all, newly registered but I've been reading through lots of threads - great info here!

I bought this truck about two years ago, just to haul stuff around locally. I don't drive it very often. I knew the valve cover gaskets were on their way out when I bought it; they were dribbling a bit - just a few drops here and there.

Now, I really notice it marking its territory when I park it.

My question is - could this all be due to the valve cover gaskets, or am I potentially looking for another problem? Also, it looks like I have to remove the intake to get to the passenger side - does anyone know the part number (or from Rockauto?) for any other gaskets I'll encounter while I'm digging in?

Truck details:
1990 F-150 XLT Lariat 4x4
302 V8
Automatic AOD

Thanks!

 

Welcome to the forums.

Well, typically the valve covers will leak. You'll need an upper intake gasket set, as removing the upper plenum to get to the passenger valve cover you might damage the original gasket. Better to have one and not need it, then the other way around(unless you have other transportation).

Check around the oil pan gasket. They also are very typical to smoosh out and leak. The factory rubber gasket can be reused, I've done it on two trucks so far. Loosen the bolts around the pan, straighten the gasket out and hold in place while you snug the bolts back down. This will usually take care of leaks for a while. My last one has gone 3 yrs now without having to actually change pan gasket.

 

Thanks Freightrain.

Checked under the truck today, and the puddle looks pretty fresh... that would imply it's leaking from somewhere at/below the static oil level, right?

I'll check the oil pan gasket, and probably just replace it with a new one.

For the upper intake gaskets, will this set work? More Information for FEL-PRO MS94951
It says Lower set; Upper set included.

 

Usually the intake set will include the "upper" gasket since you have to remove it to replace the lower gasket.

How is the rear main seal? You need to get under there while it's idling and see if it's dripping at the transmission bellhousing.

Any place that will leak, will slowly run down and make a huge mess on the ground. No real place for it to leak below oil level(unless the pan is rusted out---and that is possible too). If it's oily under there, it's time to get some brake cleaner and spray things off and see where it comes from.

 

I figured if it was leaking when parked for a few days and cold, then it must be coming from somewhere on the bottom. Perhaps the pan.

I hope it's not the rear main ... these are one piece that need the transmission removed to replace? That would be game over for my ability.

I'll check it out better with it running and see what's what.

 

These trucks were NOTORIOUS for rusting the pan out. The rust bubbles would start and you wouldn't think much. Then suddenly it starts seeping and leaving puddles.

The bubbles start due to moisture under the paint, the water would rust the pan out, then the oil would seep through the bubbles.