I noticed one of my intake manifold bolts backed out about 1" a few weeks back and another one was loose. Anyone else have this? Should I apply some blue loctite to the threads?
This happens a lot on the S4. Generally after putting in spacers or just pulling the manifold. You shouldn’t have to put any locking compound on them. Bolts tend to back out when there is a high spot on uneven tq load on them. The tq can get shifted when the car warms up and the intake manifold expands.
Try loosing all the bolts an re tighten them from the center out in an X pattern.
Thanks Justin, your knowledge is invaluable to this forum.
Unrelated, but I was hoping to find an answer to this question:
Is the Intake Air Switch Over Valve test supposed to fully open and close the valve? The test opens mine and then it flips back and forth like its stuck in the open position.
heres a video if what its doing https://www.youtube.com/watch?v=I9KRieMPzD8
Mine did the exact same thing. There were no error codes for that valve so I figured it was normal. I just cleaned out some dust and manually opened and closed it a few times, then put the airbox back together.
Just wanted to make sure I answered both places. The air box flap test is just a pulse of the flap actuator. So the test is just to make sure the actuators working. If the door is opening all the way and closing then that’s fine.