can surge valve cause knock?

[jabrax]

trying to track down a throttle surge issue and realized my surge valve has been tapping up against the body. fascia jams it up pretty good with the filter on causing it to miss the rubber pieces placed to cushion it. Filter was barely hanging on.

Figured i would ask seeing a couple of fellow procharger guys having knock issues.

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[asylum938]

trying to track down a throttle surge issue and realized my surge valve has been tapping up against the body. fascia jams it up pretty good with the filter on causing it to miss the rubber pieces placed to cushion it. Filter was barely hanging on.

Figured i would ask seeing a couple of fellow procharger guys having knock issues.

I would Imagine so if its hitting hard enough.

some headers contact the AC line bracket causing false knock and exhaust bolts further down on the midpipe contacting the body will cause false knock.

I believe another member with a paxton had his intercooler piping hitting the body causing false knock as well.

 

[donmcgowen]

Damn false knock. Having severe false knock. Think it might be the exhaust, but not sure.

 

[Bartly]

I'm just going to guess because I don't know. But my thought would be no because nothing is rubbing/hitting the engine/drivetrain/exhaust (basically anything metal that could transmit noise into the engine. Can only guess there are rubber motor/transmission mounts so the engine/exhaust and transmission is isolated from the chassis/body. But like the other guy up above said, maybe if it was hitting hard enough maybe. Sorry no real help. Yep, that area was pretty damn messed up on mine until I re-did it, still pretty tight though. Have you tried fuel additive to see if your knock goes away with higher octane? Helped me confirm my knock was real not false. Also, I ended up buying a new Gates hose (same p/n) that the surge valve hooks to from Rock Auto. It was actually shaped different than the one from the PC kit. It formed a tighter 90 degree, smaller inside corner. It seemed to help out, but it still hits the backside of the bumper facia, just not as bad.

The surge valve has two rubber hoses between it and the blower which is hard mounted to the engine, so wouldn't think vibration would travel back up that directions. Again, just a guess.

 

[jabrax]

I don't think I'm getting any knock, but was curious after seeing the metal on metal witness marks. Thinking it could be something the guys having knock issues could check.

Yeah, my fit in there was pretty jacked, the filter literally hanging off. I may have cut mine too short. I will try and buy a replacement hose before putting the fascia back on in the morning. I hate taking that damn thing off

 

[Bartly]

Yeah I hear you, I don't look forward to taking mine back apart to re-do my intercooler paint job. I was so anxious I just painted it, should have scuffed it up with some scotchbrite, the paint is flaking off. Bummer. Also, funny thing happened when I bought the hose from rock auto. The first hose they sent was just the straight section with the part ID on it. Looked like the remnent from someone's PC install that was returned for credit. Replacement was good though. Kind of made me laugh. I had no clue it would be shaped different than the one from the kit, but was a good surprise. No clue if they are all like that from rock auto or not.

Sorry no help on the knock info.

 

[ahl395]

I'm having alot of false knock issues at part throttle. Never thought about this, but I wouldnt think so since nothing is touching the engine or exhaust.

Switching to a BOV mounted on the pipe soon so if the false knock issues go away I know why lol.

 

[smokinzx14r]

My blow off valve hits in two places . My charger tube hits the core support , never once have I had a false knock .. My knock sensors are set to the factory setting ..

 

[BMill705]

I chased false knock for months and thought the same about something having to hit against the engine or exhaust. Well one day I secured a nitrous line a little better and also found a wiring adapter hitting against the silver box below the fuse box and on the next datalog knock was gone. Cant say for sure that was the cause but it was the only thing to change.

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