Problem With the 4.6 Today
 

Like the title says, I got a problem. LOL

I was driving home from my G/F house a little while ago and all of a sudden under LIGHT exceleration ( I was passing somebody driving slow in the fast lane, I was in 5th gear so it was LIGHT) . The car just started studdering and POPPING. From the inside of the car it sounded like my exhaust manifold sprung a big leak cause the sound it made was just like I had no exhaust at all. ANYWAY I pulled over popped the hood and it wasnt comming from the exhaust the noise was comming from the top somewhere. I got a buddy to come tow me the last 2 miles to my house. We looked at for like an hour trying to figure the damn thing out. We were thinking it was a cracked intake. Well he just happens to notice that one of the COPs was sitting a little out of line hes like WTF??!! THERES the problem! We started takeing the crap appart to get that COP off and when I pulled the boot up it was torn to shit and looked really bad. He got the plug socket and turns out the plug was just SITTING in the hole down in there.

Anyhow, turns out my plug hole needs a Heelio Coil or something or another. I got a hook up on a shop doing it for 85 bucks and if need be he will do the other trick that rethreads the hole and that one will cost me 130 bucks. So today sucks for me!

Anybody else ever heard of the 2V 4.6 blowing spark plugs like this? I have been thinking about and I didnt drive my car hard at all today. I think its possible the major damage happened days ago and it just finally gave out today.

your the first person i heard it come from!

sounds cheap...get it done or do yourself, altho the rethread takes 5 minutes to do yourself if you have the tool

this is a known problem with the 2V aluminum heads. there is not alot of thread material in the head for the spark plugs to thread into. anyone who has changed out there own plugs would notice that it only takes a few turns to tighten a plug before it is ready to be torqued. the torque value on the plugs is measured in IN-LBS. instead of FT-LBS., and is a fairly low value. 84-168 IN-LBS. to be exact. also, many shops and people try to change their plugs before the motor has properly cooled off. this is a major no-no, as hot aluminum is much softer than cold aluminum. as such, when a steel spark plug is threaded into an hot aluminum head, the threads usually stretch, or worse get crossed. over time, the stretched threads in the head become to weak to hold the plug in, and you get what happened to you. In extreme cases, or under boost, it has been known to shoot plugs through hoods.
So yeah, have heard of this happening.

Hey good info there brother, and thanks for the reply too! You rock, lol

no prob brother. sorry to see you have to go thru it.

The torque value is in ft-lb and 84 in-lb is way too low and 168 in-lb is too high of a torque value. Between 10-12 ft-lb is proper.

Crap, I torqued mine to 13lbs!:rolleyes: Getting the plugs right on these cars are important, espesically if you don't go with a fully threaded plug. I really do need to check my plugs it's been about 8 months since I changed them. I have a friend who has had his plugs blow several times on his Mustang, atleast three or four times.

torque values pulled right from the repair manual. also verified with my mechanics ALLDATA. they both very specifically said 84-168 in-lbs. converting to ft-lbs equals 7-14 ft-lbs. i believe they put it in in-lbs so that ppl wont take a 1/2" drive torque wrench to 'em. in-lbs torque wrenches are usually in 1/4" or 3/8 " drive.

my friends '99 did it. scared the shit out of us too.. dang 4.6's!

Here's the best fix without replacing a head:

http://www.timesert.com/html/sparkplugford.html

7 ft-lbs is almost just hand tight though. However, some of those values from the ALLDATA system are a bit fishy sometimes. For example, my mechanic friend told me that the pressure plate bolts are 33 ft-lbs + 60° while my Haynes listed it as 30 something.