# 2011 LS Intake Manifold Tuning Valve Runner (stupid design)



## alexeilb (Feb 26, 2011)

Hey Guys, 

I am sure most of you are aware of the Tuning Valve Runner arm that tends to pop off leading to a P2076 Code (2). And only true fix is to replace the entire intake manifold. I replaced my runner arm with one from a junked Cruze and haven't had problems for about 60k miles. Recently the arm came off again, but I noticed something that caught my attention (see below):










The Runner solenoid has turned all the way to the 10 o'clock (see the red arrow) which forced the arm linkage to disengage. The tuning valve turns about 110 degrees, the solenoid supposed to rotate from 2 o'clock as you see pictured to 4 o'clock which opens and closes the tuning valve. Why did the solenoid turn all the way to 10 o'clock? I tested the solenoid and it works fine, could it be computer related, a faulty PCM code? 










I end up fixing the runner arm using a nut and bolt as shown in this thread How-To: Intake manifold Tuning Valve fix (P2076)

I took two videos, one without the arm and solenoid in the 10 o'clock position and one with the arm in the proper position. You can see in the first video the solenoid rotated down and back to 4 o'clock where it should be when the engine off.


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## Blasirl (Mar 31, 2015)

@plano-doug


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## plano-doug (Jul 1, 2015)

alexeilb said:


> ...the solenoid [is] supposed to rotate from 2 o'clock as you see pictured to 4 o'clock which opens and closes the tuning valve. Why did the solenoid turn all the way to 10 o'clock?
> <snip>
> I end up fixing the runner arm using a nut and bolt as shown in this thread How-To: Intake manifold Tuning Valve fix (P2076)


I've wondered the same thing. I've found the lower crank stopped in the range 7-11 o'clock, well past bottom center (6 o'clock). Needless to say, the rod had popped out.

I had wondered if over-rotation didn't help pop the connecting rod loose. But I don't think that's the case. Instead, I believe what happens is that the computer loses track of the crank position _after_ the rod pops loose resulting in the crank being over-rotated to a non-spec position (ie, 7-11 o'clock).

There's a sensor on the other end of the tuning valve which reports the position to the computer. When the rod pops loose, the computer keeps reading the same position despite trying to rotate the crank to a different position. That is, the computer gets confused and thinks the crank is still somewhere in the safe range, 1-5 o'clock.

As indicated in the thread you cited, I believe, if the car is turned off for a minute, then turned back to ON, the crank will return to a safe position, so the rod can be re-connected. (Another attempt should be made if it doesn't work the first time.)

HTH.

Doug

.


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## alexeilb (Feb 26, 2011)

@plano-doug thank you for the explanation, that makes perfect sense. So far it's holding up, nut and screw are still in position. My car is at 160k miles, original owner. Trying to see how much I can get out the car, almost everything critical has been replaced.


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