Thermactor plug

281pony

Active Member
Aug 31, 2003
2,681
2
46
Oly, WA
im about to start my new engine for the first time and im going over everything. yesterday i bumped it a couple times to make sure it was going to turn over. just two quick bumps.

on my passenger side head, the thermactor plug on the front of the engine is missing where the bracket bolt goes. will the absense of the plug cause a major airleak?

just wondering, i heard some compression hissing out after the bumps i think and thats the only leak i can really think of it would have. i tried to feel around but it goes just as deep as the screwdriver tip i was using, are they just straight through or will it cause an airleak?

thanks
 
the rear is plugged already.

the front is what im wondering about. does it go straight through the head completely? :shrug:

i can get a plug eventually reguardless, its just right now i dont have transportation until my car is up and running. i dont want a massive airleak now and im trying to get something resolved before first startup.
 
well technically there is no front or back to the heads, they are both the same, you can install them any which way you want ... the thermactor holes/plugs are there really to just thread bolts into the heads(front brackets) or for the crossover tube (rear emissions)
 
You will have a leak at the front because as stated there isn't really a front or a back...the holes match on both sides...

Put some silicone on them when you install them and "twist" them in until they stop...

You will need the plug in the front anyways because the inside of the thermactor plug is the size threads you need to put your alternator bolt/power steering stud in...it will not thread in without the plugs...

They "plug" up the hole where the smog equipment goes (the same thing works for the front of you heads...you can get them at a Ford Dealership - part # F4ZZ-6E086-A or you can buy some from Summitracing - part # TFS-51400265...when you put them in the front of your heads your alternator bolt and power steering stud will screw right in perfectly...when I first seen they were to the heads hole threads were to big doing my h/c/i swap...I thought I put the heads on backwards :rolleyes: