anza_2002

Truck was running fine till all of a sudden today engine started banging at a traffic light. Coasted around the corner to a garage. One of the spark plugs had popped. Apparently, the threads had been striped by the mechanic who changed the plugs. Kit for inserting plug sleeve worked fine. But after replacing plug engine is still banging. Mechanic said it might be connecting rod or something else inside engine. I need a mechanic in San Diego who is experienced with these problems in the 5.4L engines. Recommendations greatly appreciated. The whole spark plug issue with these engines opens up a gigantic can of very ugly worms.

techrep

iTrader: (1)

No.. the dude that stripped your plug threads opened up the can.. did you try a new COP on that cyclinder ? any DTC's ?

anza_2002

thanks very much for your reply

this happened late yesterday afternoon Saturday and the mechanic was only able to get the plug sleeve inserted before the end of the day. I will check on Monday to see about the coil and trouble codes.

Coincidentally, my buddy's 2002 F250 v10 just did the exact same thing and he had his plugs done by a very reputable, but different, shop that has a lot of experience working on these engines. So maybe I am remiss in blaming the mechanic who replaced the plugs in my truck. Maybe it was just stripped when the plug blew out. Maybe, as it seems from the number of people who have reported this problem, it is just a flawed engine design.

jethat

the 5.4-2v engine only has 4 threads. It is common for them to blow out all by themselves the plug change my have little to do with it although most tech manual spec only torquing to 11 pounds and they should be torqued to 26 to prevent blowouts. My bet it the shop did it wrong and whatever insert he used instantly failed and you need it done right. Only Ford lock-n-stich or timesert inserts work. DO NOT use a heilicoil!

anza_2002

thanks for your reply. Assuming the mechanic did the plug sleeve wrong, is there a way to rectify the situation after the fact or would the head have to come of the engine in that case? very much appreciate the information you have provided.

redfishtd

Hopefully he didn't put a heli coil in there, they can't take heating and cooling . . Time sert is best but expensive . Most advice is to let thread locker on insert set up overnight before trying it . You need someone to carefully do that job or you will be pulling the head .
You probably have the bad year heads . In any case you either do the plugs yourself or some one you can really trust .
That means using torque wrenches and doing it right . Some shops will not even do the back ones as they are harder but they tell you they did them . Some will use power tools to install ,that's a no no on aluminum heads .
The 05 heads had more threads but the hated two piece sparkplugs that break off caused more problems . If you have these you need to study the fix for that . You have to coat the shaft with nickle anti -seize for one thing and a bunch of other stuff .
Good luck

jethat

I have all the suff to fix blow outs in my garage. Think I spent around $200 for the kit and all the suff. It's easy. I can repair a blown plug in my garage in around an hour. There are guys who rent the stuff to. It's not a big deal.

R&TBabich

The '05 heads have 3 valves and are not compatible with the earlier 2v heads.
The '03-'04 heads are 2v heads, but have 8 threads for the plugs.
The early '99-'02 heads have 4 threads for the plugs which is adequate when the plugs are properly torqued.
I think because the plugs are steel with aluminum heads after many, many heat cycles over +100K one of them will start working loose.
Mostly the middle plugs on the passenger side of the engine where temps are hottest.
With only 4 threads to hold the plugs in after a turn or two there are only 2 threads left and it blows out.
In an 8 thread head there would still be 6 threads left to hold the plug in and give you a chance to hear the exhaust leaking by the threads before it blows.
Changing plugs at 50k and checking the torque one more time at 10k should prevent blowouts.
I used a Time-Sert spark plug insert on the #3 plug in our 6.8l and it has been good so far.
The Time-Sert insert is held in 3 ways:
1. The head is bored with a new seat for the insert to be torqued against just like the spark plug. The insert has a new seat for the spark plug.
2. Thread locker is used when the insert is torqued into the head.
3. A small bump in the insert is pressed outward with a special tool providing a "mechanical" lock.