Car won't boost past 7psi and it sounds like rocks rattling around somewhere, did my supercharger die? I will post a video later tonight. It seemed I had issues with the bypass valve before because there were times it would only boost to 3psi but that issue has cropped up in a few weeks.

 

https://drive.google.com/drive/folde...x9?usp=sharing

I sent a boroscope through the throttle body to take a look at the rotors, edges seem shiny, is that normal or are they hitting each other? Also uploaded the video of the noise there too.

 

I spoke with someone at zzp and they suggested the noise is actually the timing chain tensioner. Overnighted it and swapped it out, noise is totally gone. I put 120miles on it today and all I can hear now is the injectors. It boosts like it should too now, any idea why that is? Seems to me like that shouldn't affect boost.

Also, shout out to zzp, I was about to buy a replacement supercharger.

 

That's weird, only think I can think of is maybe it was throwing the timing off slightly (retarded) and the ecu was limiting boost so it didn't run too lean.

 

That would be my guess too.

 

I have the lnf and so far (knock on wood) I haven't heard a peep from the timing chain area. 117k and still holding 23 psi of boost on the original turbo. If I remember correctly the lnf didn't have tensioner failure as much but there was one chain guide bolt that was known for coming loose

 

I'm at 130k, but I had the original tensioner. You probably have the revised version. When I pulled my old one it was totally seized.

I thought the LSJ couldn't regulate boost, It doesn't function like a turbo right? It either boosted or it didn't? Do you think maybe the exhaust valves was opening too soon and reliving pressure? Either way, I'm ecstatic it's fixed.

 

the lsj has the bypass valve and the pcm is capable of regulating boost. this is why in 1st gear you generally have lower boost than 2nd through 5th, and this can be tuned in the pcm. it can also open the bypass up as part of the failsafe strategy for codes. its possible it set a cam position code, or a cam/crank correlation code and didnt turn the check engine light on, and part of the failsafe is limiting boost. generally with the bypass wide open it will only make 5psi.

 

Ok, I assumed the bypass valve didn't have a duty cycle or anything so I guess I'm wrong on that. The car DID limit boost to 3psi randomly for a while but that was 2000 miles ago and before I noticed any dreadful noise. No codes were set at all other than one for the gas cap, I checked as soon as I noticed the loss of power so I guess I caught it in time.