The P71 is busted. Blew one of the spark plugs clean out of the head. Man I loathe these stupid Mod Motors...
Anyways, does anybody know if this can be successfully fixed with the head on, or is it time to DOHC swap this pig? Oh, it broke the damn coil too, so I need one of those as well. They always break when the income stops...
That totally sucks.
The bad news is that you'll likely have to pull the head to do it right.
The good news is that you have plenty of extra time on your hands to do it.
If the threads are blown out I can't imagine fixing things with out at least a little drilling and tapping.
That means metal shavings, I can't imagine that being a good idea in an assembled motor.
It's fixable with the head on, check out this GRM Tech Tip
http://grassrootsmotorsports.com/tech-tips/52/
ls1 time
i just got my 4.6 running right.
i've repaired plug holes via drill/tap/helicoil with head on engine. drilled, vac with small hose down plug hole, tap coated in grease to catch shavings. fyi the cheapest standard brand coil from rock auto was $27 less incl shipping than local and made in USA, just did #6 again replacing the taiwan coil from advance that i installed when i got the car 2 yrs ago
NYG95GA
SuperDork
6/5/10 10:15 p.m.
patgizz wrote:
...tap coated in grease to catch shavings.
If you do it without pulling the head, this is the best advice.
I remember something about lowering the piston and filling the cylinder with shaving cream, do your metal work, then when you roll the engine over it will push the crap out.
Joey
Your local NAPA has a repair tool and "insert" kit for this, It isn't cheap but it is cheaper than pulling the head. Comes with a special tap, helicoils, installer and a handy blow mold case because you WILL need it again!
I've done the shaving cream trick, followed by a vacuum. Worked like a charm on the Sidekick!
i can't wait for mine to blow one so I can justify trickflow heads.
What vehicles and models are suceptable to this? Any way to stop it from happening?
I have one of those NAPA rethreading tools. You know what a tap looks like, right? A bottoming tap has a flat bottom to get to the bottom of a blind hole, a starter tap has a point to help get things started.
This thing is a starter tap with a longer point which has a cutting surface like a reamer. Align it over the hole and gently turn; it cuts, it threads and it's wonderful. It cuts the spark plug hole oversize and then you install an insert, it's a threaded nipple with spark plug threads inside and threads outside that match the ones you just cut. A little Lock-Tite and you back in the game.
This is a 10 minute job that's only scary if you haven't done it before, nothing to it.
Dan
Dan,
Do you have the part #'s for the tool and insert?
If the NAPA guy doesn't know where it is he should be looking for a new job ;)
I will check my catalog after I cook lunch (I need to go to the storage unit to get the catalogs)
porksboy wrote:
What vehicles and models are suceptable to this? Any way to stop it from happening?
2-valve ford mod-motors.
there's like three threads for the plugs, or something equally ridiculous.
I ordered one of those ridiculous fix-it kits, a plug, and a coil. Keep yer fingers crossed...
Time sert is the kit the pros use.
And yes, it is one of the two stupidest things ever done to an engine.
The other stupid thing is the plug design they changed to afterwards.
Find a crapped out Mark VIII and swap the motor.