4.6 Zero compression after helicoil...
 

The truck is a 2001 4.6 F150 Automatic with 135K miles.

The truck had a plug blow out on #2, my buddy owns a shop so he helicoiled it for me. Worked ok for a day or so but started missing again but with no codes. I drove it for maybe 500 miles until it threw a code for missing on #2 again. I pulled the injectors to get them rebuilt to see if they may be clogged.

We pulled the #2 plug while the injectors were out being rebuilt and it was melted down into the threads and the helicoil came out with it. We put in a new plug, helicoil and rebuilt injectors and it was still missing so we checked the signal to the COP and injectors and both were fine. So now we know we have spark and fuel...

Now we compression check the #2 and we have pretty much zero compression...so we blow air into the cylinder and it's leaking into BOTH the intake manifold and exhaust... we turn the motor over several times and same thing each time...

So...burned valves? Stuck valves?

How much of a PITA is it to replace the valves on this engine? The worst part is Im selling it so I have to get chin deep in her for someone else :wallbash:

Any ideas? Any good tutorials? Search of google and forum came up dry.

http://i969.photobucket.com/albums/a...g/IMG_0104.jpg

Here's the plug with helicoil still on it.