: P-valve or isolator noise



Ross L
09-20-10, 10:47 PM
I've posted before about a part throttle noise or rattle. No detonation is showing on the scan tool and no codes are being thrown. When the engine is running I can move(thrust) the P-valve rod going into the supercharger inlet approximately 1/4" and it makes a noticable rattling sound. Can I unhook/bypass the p-valve to eliminate it as a source of the "rattle"? The isolator is also making a slight noise at idle, but nothing major. Can the car be driven with the blower belt off? I really don't want to take it to the dealer.Thanks for any input.
Ross

Domsz06
09-20-10, 10:55 PM
probably your isolator inside your snout area. Every vendor on here sells it. GM made theirs spring loaded, the after market one's are solid.

Ross L
09-20-10, 11:00 PM
Thanks, thats my thought as well. I would probably sell the car if I did the soild isolator and the noise was still there(getting frustrated). I just don't know what else it could be. The dealer said it was the injectors and normal. It can easily be heard inside the car at 65 mph with the windows up when passing another car on the highway. Guess I'll order the isolator and see. Thanks
Ross

Domsz06
09-21-10, 12:51 AM
Thanks, thats my thought as well. I would probably sell the car if I did the soild isolator and the noise was still there(getting frustrated). I just don't know what else it could be. The dealer said it was the injectors and normal. It can easily be heard inside the car at 65 mph with the windows up when passing another car on the highway. Guess I'll order the isolator and see. Thanks
Ross

I'm by no means an expert as I just got my car, but just learning from reading. I have gathered I got lucky on my car as I have none of these issues everyone talks about, but mine was actually an 08 build...

I suggest you all Jesse, or Cliff and talk to them. I have not talked to Jesse but he gets good reviews on here, and have talked to Cliff and he is just as knowledagble as jesse.

They will help you!!

Keep us posted and don't sell it yet!!! ;)

Gary Wells
09-21-10, 03:48 PM
My SC isolator went out at about 1200 miles. Generally first noticeable at idle or just coming off of idle. It can't get any better, and it will get worse with time and / or mileage. It's only like a $ 70.00 item or so, and most of the bigger name tune shops stock them or can get them. They universally replace with a Lingenfelter solid isolator. HTH

Ross L
09-21-10, 06:19 PM
Ordered this am. Might as well do a upper pulley, thermostat and tune while I'm in there ;-)

Gary Wells
09-21-10, 07:17 PM
No sense in going in there 2X if you don't have to. If you are farming the SC out to have the upper pinned might be a convenient time to have the SC snout ported / polished. Just a thought.

Ross L
09-21-10, 09:15 PM
Yes, yes, yes that makes perfect sense Gary. Stop being so helpful, lol. I'll be doing most of the work so I'll consult with someone to help with the porting. BTW, this is NOT my wife's car. It is a friends. Again, not my beautiful, sweet , forgiving wife's car.

Gary Wells
09-21-10, 09:49 PM
Ross L:
Unfortunately, being in the sunny Republik of So Kali, mine is still bone stock. Still debating about the warranty, the smog narcs, etc., etc.
What I have heard from reading on here though, is that the porting is very worthwhile, not necessarily in RWHP & RWTQ, which is generally only about 6 or 7 in real life #'s, but I hear that definitely improves throttle response & bottom end. I have also heard that it improves the transition period between idle & throttle. I think that Jesse Bubb advised that he got about 38 or so RWHP, but that was with porting the whole SC, not just the snout. If I was brave enough to take mine apart, which I am not, I probably would do mine or have it done, but if I ever have my car done, I will have it done.
HTH