Conversions & Hybrids - What would cause coolant to seep ftom Header bolt???

05-25-2011, 10:32 PM
I have about 1 hour of run time on my LQ9, and I started to see coolant seeping from only one header bolt. This worries me... Headers are Edelbrock A-body swap headers installed with bolts that came with kit and anti-seize. Does this seepage mean there is a crack in the water jacket and it is spilling into the header bolt hole??? Thanks!!!

05-25-2011, 11:00 PM
header bolts should not go into coolant passages at all. Make sure the leakage isn't from a higher place on the motor and just seeping around to the header bolts, otherwise you have a cracked head possibly.

05-25-2011, 11:43 PM
which side? on an ls1 you have a port right next to the last header bolt on the back passenger head. If there is no plug in it then it will leak a lot. That could be what you are seeing, or the plug could be leaking.

05-26-2011, 05:16 AM
Take the header bolt out and see if there is a a bigger leak, somebody could have bottomed out a bolt in that hole and crack or broken out the bottom of it. If that's the case put some sealer on the bolt. I've used thwe copper colored permatex silicone when I ran in to this issuse on a non-LS motor with aluminium heads