In July I had a Hotcam installed with LS6 springs. Also installed were ASP pulley, Katech oil pump, thermostat, LS6 intake, Rollermaster double row, and the stock pushrods were checked and reused. Occassionally when the car is operated at constant rpms (highway particularly) it will pick up a fluttering noise near the AIR tubes or drivers bank on the engine (slight tapping). It will go away if the car is shut off for a while, or if the rpm range is run around a little. I was curious what everyone's opinion may be. Lifter, pushrod, rocker arm, exhaust leak, injectors, pushrods. BTW the car idles at normal speed, and all the guages (even the oil pressure) read normally. Thanks.

 

Did you do the AIR pump restrictor plates? Not sure what all are the symptoms, but might be it if your hearing a fluttering/tapping. Something about making a palte to cover up most of the AIR tubes where they connect to headers.

 

Yes, I made block off plates for the EGR with 22 guage sheetsteel. The AIR system is still hooked up. It seems to only show up during constant rpm operation, and mostly on the highway.

 

I think an AIR restrictor plate is the answer. This is unrelated to EGR.

I had LTs and the Hotcam and was stunned by that noise until I figured out it was the AIR. Do a search and you'll find some details somewhere on how to use some sheetmetal to fashion a restrictor bewteen the header and the AIR connector flange.

chris

 

It scares the sh*t out of me. I was really concerned about rocker arms, lifters, etc.; but I know the cam was put in by someone who has done quite a few. The car runs strong and shows no guage fluctuations while it flutters. It just sounds kinda creepy. Its seems like everyone thinks that the AIR system is getting its panties in a bunch. I guess after emissions this month, the AIR system will have to go.

 

well, you dont have ot bail the whole AIR system, especially if you are going to start setting codes (it will). Just put a restrictor plate (not a block off plate, just a plate with a smaller hole in it) and you will be AOK. No panties involved.... (unfortunately)

chris

 

TTT