Spark plug Threads melted

Hi All, Looking for possible solution,

2001 F-150 Smaller V8 "4.8L", "Triton". Driving the vehicle underload "Camper" heard what I though was a loud exhaust leak! Inspection showed that the coil on passenger side/3rd fromt front was dangling on top of the engin block...not a good sign..

Turns out that threads are striped and hot gases melted the remaining thread to mount spark plug. I had a local chap come by and re-tap the thread and install a Helix-Coil ?. Have not fired the engine up yet as two things are not certain. 1).Turned engine (without spark) over with new plug in place and a slight leak still present between helix and old thread - not good. 2) how long will this type of patch maintain itself?

I would like to add some type of putty material that could harden would assure a proper seal to this new fix. Can I use a material in conjunction with a spark plug that has a compression washers to further prolong the inevitable...replacement of the head. As this truck has many miles on it ~135k I don't see that value in spending $2000.00 in fixing it. Would like to keep it runnin after a fashion for use on the farm.

Your thoughts.

Marc

Reply to
Pogo
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"Pogo" wrote: ( 2001 F-150 4.8LTriton V8)

A spark plug on the passenger side (3rd from front) blew out because the plug hole threads had stripped. A friend re-tapped it and installed a Heli-Coil.

I cranked the engine (without spark) with a new plug in place and a slight leak is still present between the old thread and the Heli-Coil.

Can I seal the leak with some type of hardening putty in conjunction with a spark plug that has compression washers?

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No sealant needed. Buy or make a copper washer with an OD a little larger than the OD of the Heli-Coil.

Note: There are probably metal chips in the cylinder from the Heli-Coil tapping. This may cause problems.

Good luck.

Rodan.

Reply to
Rodan

Will consider the copper washer. took great care not to get metal chips in cylinder, copious amounts of grease injected in cylinder cavity scooped and flushed out after heli-coil install, though there is a risk of contamination.

Reply to
Pogo

Helicoils are not a good repair for this failure. Ford has authourized only one type of insert -

Reply to
C. E. White

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