LQ9 head gasket leak
#13
Custm2500's Rude Friend
iTrader: (17)
the motor was out of a 2005 or 6 2500 work truck, started life as a lq4 but was in cab fire. i pulled everything off and took it to the machine shop, had everything check to made sure was straight or machined to be straight and bored out .030. the heads (317) are the ones that came with the engine.
as of right now I have the heads off and i got some cometic gaskets and arp bolts. I chased all the bolt holes and I'm waiting on some water to evap. the gaskets I had on this morning were flat as a board, the cometic gaskets have little bumps and ridges around most of the passages. I ran a straight edge on all the surfaces and i dont see any light or low spots, I checked my dowel pins and they are clearing (it had crossed my mind that they may be too tall). before i pulled the heads i did look in the cylinders to see if the bores had coolant in them too but they were dry. it was just leaking down the bottom of the head but it only did it after i jacked the front of the truck up and let it sit over night like that. it had sit for about 4 days with coolant in it before it started leaking.
as of right now I have the heads off and i got some cometic gaskets and arp bolts. I chased all the bolt holes and I'm waiting on some water to evap. the gaskets I had on this morning were flat as a board, the cometic gaskets have little bumps and ridges around most of the passages. I ran a straight edge on all the surfaces and i dont see any light or low spots, I checked my dowel pins and they are clearing (it had crossed my mind that they may be too tall). before i pulled the heads i did look in the cylinders to see if the bores had coolant in them too but they were dry. it was just leaking down the bottom of the head but it only did it after i jacked the front of the truck up and let it sit over night like that. it had sit for about 4 days with coolant in it before it started leaking.
The other thing would be the coolant Plug in the rear of the head or the cross over in the front. They have a small o-ring on the bottom that should be changed when you service the heads.
#18
I have a torque angle meter and I used it just as instructed by the book (well the book i was using anyways) I think the gaskets were just too cheap and flat as a board. I even used to different torque wrenches just to make sure the torque specs were met.