LQ4 Heads
Thread Starter
Teching In
Joined: Mar 2011
Posts: 6
Likes: 0
From: Fort Campbell, Kentucky
LQ4 Heads Working on a 2001 LQ4 and the customer replaced the headgaskets. He couldn't get it started so he had us tow it to our shop. The problem we found is that the passenger side is working properly, but the driver's side is sucking air in from the exhaust. Pulled head and checked and valves are fine. Hand ground valves just to make sure they aren't leaking and they seal up fine. Can't seem to figure this thing out and need some help. Also customer got me another 317 casting head but it came off the passenger side of the vehicle it was on and the messed up head is the driver's side. Not sure if i can change the side the head was on the block or not. Any help is greatly appreciated.
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
Heads are 100% identical. Can be interchanged side to side.
Other than improperly torqueing down the rocker arms, there isn't much he could have messed up. Maybe connecting the coils or injectors wrong?
Other than improperly torqueing down the rocker arms, there isn't much he could have messed up. Maybe connecting the coils or injectors wrong?
On The Tree
Joined: Jun 2016
Posts: 135
Likes: 0
From: New Franklin, OH
I do beleive the heads are interchangeable. I don't think there is a left or right head. did you spin the motor with the heads on and covers off to make sure the valves were opening and closing?
Thread Starter
Teching In
Joined: Mar 2011
Posts: 6
Likes: 0
From: Fort Campbell, Kentucky
Thank you I'll install this head than.The only thing that doesn't make any sense to me is the sucking from the exhaust. To me it would be piston rings or a valve issue, but everything is testing fine.
Thread Starter
Teching In
Joined: Mar 2011
Posts: 6
Likes: 0
From: Fort Campbell, Kentucky
Yes I did and also tried with intake off and still getting a suction from the exhaust manifold. Checked valves and piston rings and everything is good. Never seen anything like this before.
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Thread Starter
Teching In
Joined: Mar 2011
Posts: 6
Likes: 0
From: Fort Campbell, Kentucky
The timing was never touched. Didn't touch cam or bottom end at all. Just replaced the head gaskets.All the push rods were original, but 1 which he lost and replaced (atleast thats what I was told).
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