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LQ9 head gasket leak

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Old 05-26-2019, 04:43 PM
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Originally Posted by terravast4
Some heads from a certain year require a specific head gasket because of an odd water passage. I can't remember the year right off hand. I know Scoggin dickey had images on their site to show the slight differences
Thanks I'll check it out, I was sure the water passages were lining up good but I'll check again.
Old 05-26-2019, 08:28 PM
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Originally Posted by terravast4
Some heads from a certain year require a specific head gasket because of an odd water passage. I can't remember the year right off hand. I know Scoggin dickey had images on their site to show the slight differences
That was the early 4.8L/5.3L engines with 862 heads that had a notch in the deck. Some early LS1 ones also had this with the 853 heads.

This does not apply to the LQ4/LQ9 with 317 heads.


Old 05-26-2019, 08:31 PM
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Originally Posted by firebladeJJ
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.
Sounds like a possible issue with the gaskets you had.

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.
Old 05-26-2019, 11:34 PM
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Originally Posted by 1FastBrick
Sounds like a possible issue with the gaskets you had.

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.
I hope it was just a gasket issue. I need this thing running. I'll check those orings again, make sure they are still there.
Old 05-28-2019, 10:36 AM
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Looks like it was just an gasket issue, I got it started and a quick little drive for a log file so Atomic can make sure everything is OK with the tune then I'll start breaking her in.
Old 05-28-2019, 11:20 AM
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Glad to hear!!! Thanks for reporting back
Old 05-28-2019, 12:31 PM
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When I put my 706 heads on, I didn't have a torque-angle meter so I improvised with referencing a clock dial in my head. I used to different color sharpies, red/black to make marks and where I started.

Seemed to work ok so far.
Old 05-28-2019, 03:45 PM
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Originally Posted by madmann26
When I put my 706 heads on, I didn't have a torque-angle meter so I improvised with referencing a clock dial in my head. I used to different color sharpies, red/black to make marks and where I started.

Seemed to work ok so far.
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.
Old 05-29-2019, 02:51 AM
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Originally Posted by firebladeJJ
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.
The MLS gaskets should not be completely flat. They should have a raised ring around the coolant passages and the cylinders as well as a coateing. This helps them seal.

Thats was likely the issue with the last set.
Old 05-29-2019, 06:49 PM
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Would anyone care to guess why my truck is now killing the battery ? Brand new got it Saturday. It started yesterday fine. I cleaned the main negative cable connection on the block. Where are the other grounds at?


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