Crickets (high pitched squeel)
 

A few guys were workin on my friends 7 fixing some of the hose problems. When we started it up it make a high pitched squeel that went away. But when we started moving the squeel started and got lounder with the RPMS. Any one have any ideas? It sounds like it's coming from behind the UIM.

Thanks,
Dan

Could be a sign of your secondary turbo going. The only other thing it the airpump..

I'm going to go out on a limb and say it may (and probably isn't) be your A/C clutch. On the new FD, the clutch is going out and it squeals like no other until it's warmed up and it still squeals quite a bit. Just my idea. Do you have a PowerFC?

No power FC, and it's not the clutch. I doubt it's the air pump seeing as that we didn't even touch it.

there was a broken vaccum hose coming off the fuel pressure regulator way under the UIM. to get to it we had to take off the UIM, and the AVC(?) underneath of that. we also replaced about 6-8 other vaccum hoses that we had to take off to get everything else off.

when the car is sitting still or moving, hit the gas and while the revs are climbing everything is normal, but when you let the revs fall there is a very high pitched sqeal like crickets coming from behind the UIM around the FPR itself.

any ideas?

ok after reading this thread: https://www.rx7club.com/showthread.p...ghlight=squeal

i'm afraid that it's probably the metal disc in the ACV. it fell out when we had it off, and we put it back in, but weren't sure what side of the gasket it was supposed to go on. FUCK! well, atleast we know where to start, that's where the sound is coming from too........ GODDAMN THESE RX7's!!! haha

Its defintely a gasket that is leaking when under acceleration or the turbo. I would check them for shaft play also Danny boy.

UPDATE:

ok well today we took the UIM back off and also took off the ACV again to get to the metal disc in the middle. turns out we had it on the wrong side of the gasket. so we put it in the right way and put the car back together. everything was running smooth for about 5 miles, but then at a stoplight the chirping sound came back. this time it isn't as high pitched, but it's still a chirp.

it only happens at idle, when the car is accel/decel it sounds fine, but when the car is sitting still it's a constant chirp sound that is in rythm with the engine. so it seems like air. i dont think it's a belt because the sound isn't coming from that area of the engine bay. more like under the UIM somewhere.

any ideas? we've searched for chirp, squeal, sqeak, etc...

I had a squeely noise when I hadn't reinstalled the extension manifold grounding wire right. The sound was coming from where you describe.

Where exactly is that ground? Is it the one that attaches to the rear of the UIM?

Yeah, it has the weird bracket that looks kinda like a handle attaching to the UIM. It would give me the squeel even when it was on (although loosely), until I tightened it down and completed the circuit. At first I thought it was maybe my ACV because I had taken that off, then I thought it was maybe a check valve, but all of those that I could see checked fine.

thanks, i just went out and checked it on the car, it looks alright, but it wasn't bolted directly to the car. it was bolted to the bracket that holds one of the lines up, so i just switched those so that the ground bracket is now actually touching the body of the car. i also just retightened the other end, so hopefully this will solve it. if not, maybe the stock ground is just shot? after having taken it off so many times in the past. it's pretty flimsy to begin with.

but thanks, i really dont think it's the ACV because we put it back together perfect this time, unless that little metal disc is malfunctioning or something.

PMed you back. It helps the grounding immensely if you sand off the paint where it contacts. I ended up doing that.

1. Remove ACV and all associated vaccum lines.
2. Cut 1/16" aluminum plate into shape of ACV with jigsaw.
3. Use liquid gasket on plate and cover opening.

4. If possible, extend this to every single solenoid on the car except wastegate control and purge control :D :D