Hi Guys, Just finished a plenum pull/ injector upgrade and some tidying up. I got everything back together and turned the key on and there was a buzzing from the rear of the engine bay? I went around and unplugged things to track it down. Turns out that when i unplugged the TPS it stopped. It was not the TPS buzzing but it must be effecting whatever is buzzing. This was a replacement TPS that i put on as I thought my previous one was on the way out. I put the old one on and buzzing went away but i noticed that in opening the throttle the buzzing came on again at about 1/4 throttle and turned off again soon after. Dosent seem to be detremental to the running of the car just curious as to the reason why? I has a look through but could not see anything on this. Thoughts...
I got the same thing. I can change the pitch with the accelerator pedal. The noise is at the starter motor for me though.
Did you.. take off the IAA unit (idle control)... When I did my plenum pull I took it off, and when putting it back on, I had forgotten to tighten up two of the little bolts holding the unit onto the plenum. When the engine started, the air passing through the plenum and the IAA caused a loud buzzing/hissing sound as the air escaped between the gasket. Tightened up the bolts, and the noise disappeared.
check and reset your TPS, there is a solenoid on the auto tranny that will buzz even when the engine is not running if it is out. I can also get it to buzz by pressing my accelerator while the engine is off thus changing the position of my tps. I even believe it trips a flag on consult not sure which one as my cable is not working now. I may be wrong about this or it may be something that is working in tandem with the tps
Transmission solenoid easy check. Brock, I get a noise under the conditions you described. I call it a growl rather than a buzz, it changes tone as I work the throttle. One way to make sure we're talking about the same thing, disconnect the plug for the solenoids and see if the noise goes away. This plug - If you reconnect the plug with the ignition still on you might have no more noise and maybe an ATCU fault code, just turn the ignition off and on and you should be back to normal. I reckon it's the line pressure solenoid growling. It's supposed to be modulated using the TPS amongst other things. My Zed has always made this noise. Have fitted a new TPS, new OEM solenoids, had the ATCU overhauled by Injectronics, still doing it. So I take it to be normal. ( at least I hope it is ) What's unusual in your case is that the replacement TPS gave you the noise with a closed throttle.
Yes, this is ringing bells for me. I remember checking all that and putting it down to a solenoid in the transmission. I have found a way to rid the sound though, 5 speed manual gearbox
