SPDEMON

Guys, I'm having a noise issue on my 95 Z28 Auto trans. Sounds like something getting switched on and off that has some sort of fan in it, but unlike a cooling fan noise. The car has 145K on it and is my GF's DD. Runs great and is mostly stock with some bolt ons.

Mechanically the car runs great and the noise doesn't seem to be affecting the performance of the car. Its just annoying/embarrassing, even though its not that loud.

It seems like the noise is not consistent with the rpms of the motor, like an accessory, and it seems to cycle on and off while running the car. I'm guessing it would be the AIR pump. Only because I know that the AIR pump is electric powered and probably doesn't run all of the time.

If i simply disconnect the electrical wiring to the pump, will it throw a CEL code?

The alternator is pretty much brand new- an A/C Delco unit, and it has a new-ish MSD OPTI and a Meziere EWP.

Do AIR pumps have a history of going out? Or are they pretty good for the like of the car?

Thanks in advance. Let me know if you need to clarify anything.

Kevin97ss

Years ago I had received a recall notice for the air pump on my '97, so its possible it could be failing. If you suspect it is at fault unplug it to see if the noise goes away but it will turn on the CEL. If it is not the noise plug it back in and the CEL will go off after a few drive cycles.

leadfoot4

iTrader: (1)

Now that you mention it, there was a factory service bulletin issued for these cars, way back when they were new. The recall pulled the plug from the pump, and capped off the wire harness end.

Kevin97ss

Courtesy of Shoebox:

Product Emission - Air Injection Reactor (A.I.R.) Pump System Failures #99083
99083 -- Air Injection Reactor (A.I.R.) Pump System Failures
1995, 1996, 1997 Chevrolet Camaro and Pontiac Firebird Model Vehicles

Equipped with 5.7L Engine (RPO LT1-VIN Code P)

Condition
General Motors has decided to conduct a Voluntary Emission Campaign involving all 1995, 1996 and 1997 Chevrolet Camaro and Pontiac Firebird model vehicles equipped with 5.7L (RPO LT1-VIN Code P) engines. The Air Injection Reactor (A.I.R.) pump emission control system on these vehicles may fail to operate and cause the Malfunction Indicator Lamp (MIL) to illuminate. This condition may be due to corrosion of a solenoid internal to the A.I.R. pump.

Correction
Dealers are to install a new A.I.R. pump assembly kit that is designed to protect the A.I.R. pump system from failing due to internal corrosion.

Vehicles Involved
Involved are all 1995, 1996 and 1997 Chevrolet Camaro and Pontiac Firebird model vehicles equipped with 5.7L (RPO LT1-VIN Code P) engines and built within the following VIN breakpoints:

Year Division Model Plant From Through
1995 Chevrolet Camaro Ste. Therese S2100001 S2229521
1995 Pontiac Firebird Ste. Therese S2200001 S2256723
1996 Chevrolet Camaro Ste. Therese T2100001 T2166869
1996 Pontiac Firebird Ste. Therese T2200001 T2232760
1997 Chevrolet Camaro Ste. Therese V2100002 V2160181
1997 Pontiac Firebird Ste. Therese V2200001 V2232666

SPDEMON

Hey Thanks a ton for that Info Kevin97ss!

I'm gonna try and unplug it and see if the noise goes away.

Anyway to "hotwire" the pump so I can hear it run without the engine running?

Kevin97ss

Your welcome, but I just copied one of Shoebox's post so he gets the credit.

Easiest way to test it would be at the relay in the box on the drivers front inner fender.

SPDEMON

Do you know which relay it is?

Do you think it will be listed in a regular Haynes/chiltons manual?