PI Heads, how to identify them?

[rodo77]

Hi, Looking in threads in the forum and info over the internet, i figure that are 2 types of heads in the modular 4.6 ford engines for the Grand Marquis and Crown Victoria.
But there's any way to know which type of heads i have in my car, witouth remove them from the engine?.
My Car is a 2001 model sold in Mexico, and as all the Grand Marquis was assembled in Canada.
Currently i don't have any problem with the heads or the plastic intake manifold, But just I want to know this information, in which case that in the future I need.

The intake manifold have a small water leak in the termostat housing, but i think that maybe don't have the o-ring, because i see a lot of silicone in the area.
Today i bought the termostat, o-ring and the reservoir cap, This Sunday i will change them.
The next weekend i will put new antifrezze, when the leak is repaired.

[pantera77]

If it's an 01 it should have PI heads.

[mcninetyone]

Every time I see a lot of silicone around those intakes, it's been a cracked manifold.
Good Luck!

[sly]

Correction: 18 ft-lbs (25 Nm) torque on those thermostat bolts.

[rodo77]

Thanks for the info about the heads.

Yes, it has a small crack on the inside where the thermostat, which in fact had no thermostat and had not noticed me going.
I put a joint sealant for plastic, let it dry and install the thermostat, o-ring and put some silicon because it looked that did not close properly the elbow of the thermostat.
** the engine had only water, and there are already 2 times I put water only and drain to keep out the rust, tomorrow i will buy a coolant flush to clean the system, and add antifreeze and distilled water.

I also bought the coolant recovery cap, because it was leaking a bit when the car was cooling.

[pantera77]

Every time I see a lot of silicone around those intakes, it's been a cracked manifold.
Good Luck!

Yep, if it's already gooped up with silicone it's probably time for a new intake.

The plastic crossovers all fail sooner then later.

[rodo77]

Yes, in the near future i will need to change the intake, i ask in the local autozone and it cost $3,700 MXN - 200 USD (Dorman).
Yesterday when i install the termostat and o-ring i had to put a lot of silicone, because there's a small leak that runs to the coils.

But at this time i don't have the Money and time to do it, Maybe in March i can buy the intake.

Thanks.

[knucklehead0202]

The intake on my '98 had the aluminum crossover when I got it, but then the goddamned thing cracked in the back where the heater hoses came off. Had to replace it anyway...
Dorman isn't the best choice but it'll do. Lots of people get a junkyard PI intake but your experience may vary.

[sly]

I've seen on the internets... people epoxying brass fittings to the intake if the plastic breaks. Drill out the plastic and fit the brass fitting in.

Basically take one of these:


and install with a washer above and below the drilled out hole and a flat nut pressing everything together with the epoxy between the washers and the intake with enough epoxy to attache itself to the fitting and the nut to make everything permanent.

Also a good way to port the driver side head to get better cooling.

some just used some threaded pipe and not a nipple.

[knucklehead0202]

^ Problem was that mine had brass ones like that built into the plastic, which cracked outward from it. Screwing brass into plastic is also asking for trouble, eventually would split. If you were to do that with a plastic I.P. to barb fitting it'd be better. Glad to be back to a car with a metal intake manifold.

[sly]

ah. Yeah... the outward cracks lead to failure at the edge of the manifold. The epoxy fix does add extra support if just the barb breaks off. And the double washer increases contact area by a very large amount. The washers have to fit pretty damn exact to work though. There are all aluminum intakes for PI motors... though they don't seem to be any better (and usually worse) then the plastic one from Ford.