First Post

Ok … I need a bona fide guru!

I have a 99.5 5.3 Chevy Silverado with 34,000 miles. Truck sat for 3 years. I have now resurrected it. Have put 3” x-Pipe, new cats, K&N drop in, Taylor wires, Iridium plugs, Westers tune. Soon to get e-fans and Aem filter set up.
PROBLEM #1. … when WOT the truck spews coolant out the overflow. Though it was a junk stat, put in new stat, had coolant system flushed and rad rodded out. Still … under WOT spews coolant out the overflow hose.
Problem #2 … Don’t know if the two are connected … am loosing power, running rich on bank 2 (-9.2). Think truck is running rich on that side, then the computer is calling for it to lean out … which gives very bad S/Knock and loss of power. Thought this was bad O2 – scanner said the heater in O2 was not working – so we replaced it. I am at my wits end.
???? …. could there be a bad head gasket … causing pressure in coolant under WOT and leaning it out under WOT?

 

take it to a shop and have it pressure tested, what your telling sounds like the head gasket is getting ready to go, hope it is not a cracked head.