[akboyd87]

I know this as been written up many times before, but I can't seem to figure out the issue.

My 2011 335i (N55) has what I assume is the VRSF aluminum charge pipe installed. I only say that because I didn't install it and resembles the same one that I installed on my X5. Anyway, I've been getting the CEL for low boost for quite a while now. The one where it turns on under moderate to heavy accel. and then goes away once you turn the car off and back on.
At first I thought it was the valve cover, but I replaced that because I knew it was damaged and leaked air (my fault ).

Turns out there is air escaping the connection between the charge pipe and TB.

As many of you know the connection between these aftermarket aluminum pipes and TB are somewhat loose.
I ran a pressure test from the turbo inlet (through the pipes, intercooler and into the TB/manifold). As soon as it got up to maybe 5psi, the air was rapidly escaping this connection and would stop if i held the pipe in place or in certain positions. I checked that the c-clip was seated as well as the rubber o-ring. It wiggles no more than my X5 does and that doesn't have any issues. I spoke with someone at VRSF and they said it was normal to be loose (for expansion).
I'm no expert, but wouldn't air/boost pressure force the pipe away from the TB? Not that it makes any difference in this situation. Any thoughts?

[Jsmz]

You should try using the o-ring that comes with our oil filters. It seals it up nicely.

[akboyd87]

Forgot to mention I ordered and installed a new OEM o-ring. Is the oil ring the same size?

[Jsmz]

I think it might be just a little bit thicker. You'll have to smear some oil on it to get it on the throttle body. It's tight.

I had a leak there also, with the oil filter o-ring I've tested up to 25psi leak free.

[akboyd87]

Ill try it out. Thanks!