2001 Ford F-250 5.4 ?

[Rick Modena]

Water in number #8 spark plug valley. It happens about once a week, truck starts missing after about a week and there is rusty water, we clean the plug area and a week or so later its starts missing again, thoughts?

I'm thinking cracked intake like the 4.6 2v GT's?

No milkshake in the oil btw.

[Mach1]

I think my 01 F250 has an alum coolant xover.

[LS1Goat]

A pressure test of the coolant system will tell the story. I would start there.

[Rick Modena]

I think my 01 F250 has an alum coolant xover.

Just a FYI the #8 is in the drivers side back of the head.

[JimD]

Prob cracked intake, but the heater core hoses are in that area also. As previously mentioned pressure check is in order.

[Mach1]

Doesn't water only pass through the front of the intake, does the intake block off the water ports on the back?

[Rick Modena]

Very little coolant is missing from the overfill tank

[shumpertdavid]

Possibly the Heater Hose Connections (located above #8 coil) or heater hose, or the coolant port at the back of the head. IIRC the intake blocks the port off, the gasket could be leaking/seeping there. It's a plastic gasket with rubber inserts similiar to the vortec chevy and 3.1\3.4 chevy's, common leak.

[Greenster95]

Leaky intake manifold gasket.

[Juiced4v]

I had the same issue...it was water coming in through the cowl panel everytime it rained or I washed my old truck.