JC316

I am working on a 99 GT convertible and this is really bugging me. I got it and it was hydrolocked with anti freeze on the number 2 cylinder. Once I cleaned that out, it fired right up and ran smooth. So, I figure it's got to be the head gasket and I tore it down. Found cylinder 1, 2, and 3 all completely clean and shiny, which means that they were getting a steam bath. Now, the head isn't warped and I am not seeing any damage to the head gasket. Checked the block and I am not seeing any cracks, same goes for the head.

In fact, the only thing that I did find odd is how easy it was to break the head bolts loose. I am used to those suckers taking nearly every ounce of my strength with a breakover bar, but these let go super easy. So easy that I bet I could have broken them loose with a ratchet alone. Are there any known issues with the stock bolts stretching?

I was getting a crap ton of anti freeze into the cylinder and I can't see where the hell it was coming from. Any ideas?

zero2005

you didnt re-use old head-bolts did you? thats a no-no. they are 1 time use only.

JC316

Yeah, I know that the bolts are TTY. I just got the car, so I have no idea what the previous owner did, but this motor has never been opened before.

cliffyk

Not a definitive answer by any measure, however I have seen some very strange and unexplained similar shìt over the years--it just happens.

Check the block and head for poor areas of the casting that might have broken/corroded through...

JC316

Already done, one of the cooling passages has some surface pitting, but nothing that would cause this. Heads and block are as straight as an arrow. Going to chalk it up to one of life's mysteries, will have it back together in a day or two.

cliffyk

I knew you'd be a step or two ahead of me--I agree with your assessment, sometimes "it" just happens...

wifes pony

Some cracks will only appear after being heated. The only way to be sure is to have heads magna fluxed. Then you'll know fer sure.

JC316

Magnaflux wont work on an aluminum head. I have see some bad cracked heads, but nothing that would cause that much water to get into a combustion chamber.

Kos

I had a similar problem with antifreeze in two cylinders. It turned out that there was a crack in the plastic intake maifold right where the thermostat was located. Coolant was being sucked into the manifold. Had to replace the manifold (0n a 2003 4.6)

JC316

Will check that, but the cylinders that flooded are on the opposite side of the thermostat. Also, the intake ports on top of the head are filthy, not clean like I would expect if it were sucking the coolant in through the intake.