I’ll do my best to describe the details as I recall. Just bought this 2005 Enviy with the 4.2. Needed the frame welded for inspection but I got a deal. Drive it around for 10 minutes, went to the title place and signed the papers. Then drive it for about 25 minutes to my brother-in-law’s garage. Was overheating but I didn’t know it as the gauges don’t all function. Lost power and misfired pretty badly and wouldn’t start once I got it parked. Next day it starts and he fixes the frame. No idea how it was running. I went to pick it up and it’s misfiring badly. Filled it with coolant/water to get it the 20 minutes home and made it (barely). Still has fluid boiling up and out of the cracked overflow tank when I got there so at least I know it wasn’t dry.
Checked for codes with my cheap tool. Got a P0301 cylinder 1 misfire. Changed only that plug. P0301 code. Swapped coil 1 and 2. P0300 code random misfire.
Swapped coil 2 to 3. Same. Swapped everything back to original spots (with the new plug in 1 and I’m still getting the P0300 misfire.
Biggest current concern: I cooked the engine and blew a head gasket. No evidence of coolant in oil. Plug 1 was dry, no coolant in that hole.
Any ideas of what to try next?
It’s acting very similar to my old 09 Traverse when the catalytic converter was clogged up. Anything that could have happened when it overheated to cause that? Worth a check?
Checked for codes with my cheap tool. Got a P0301 cylinder 1 misfire. Changed only that plug. P0301 code. Swapped coil 1 and 2. P0300 code random misfire.
Swapped coil 2 to 3. Same. Swapped everything back to original spots (with the new plug in 1 and I’m still getting the P0300 misfire.
Biggest current concern: I cooked the engine and blew a head gasket. No evidence of coolant in oil. Plug 1 was dry, no coolant in that hole.
Any ideas of what to try next?
It’s acting very similar to my old 09 Traverse when the catalytic converter was clogged up. Anything that could have happened when it overheated to cause that? Worth a check?