Hi everyone, I'm new to the Rx7 as we got this car from my wifes father who passed away last year. We had it transported from Manassas Va. to where we are in Redmond Washington. The car had been sitting in his garage for the last 25 years. It has 92K miles on it. It is a 1987 Rx7 FC. I'm trying to get it drivable again. I have taken the gas tank off and had it serviced at a radiator shop and I put it back on and fresh gas. I replaced all the 4 belts, I have flushed the radiator and engine block, I changed the oil and oil and air filter. I have put new tires on it. The engine sounds great when running but for this buzzing noise that won't stop with what seems to be coming from the dashboard. The buzzing noise won't stop. When I start it the buzzing noise begins immediately. When I drive it the buzzing noise is constant, it does not increase or decrease with the speed you are driving. The dash cluster does not light up. I have checked both the radiator and oil pressure sensors to see if they had broken wires or bad connection but they are fine. I checked the fuse box in the engine compartment but they all look good to me.

Any suggestions or ideas would really be appreciated, Thank you Haroldredmond

 

You said you checked the radiator sensor - are you talking about the single wire one in the top tank which sits underneath part of the air intake? That's the level sensor that will cause buzzing if it's bad or the coolant level drops below it. You can verify it by disconnecting and grounding the wire that goes to it - if that stops the buzzing, either coolant is low or the sensor itself is bad.

 

I had this exact same problem, and my fix after taking everything apart and putting it back together is on this thread:

https://www.rx7club.com/2nd-generati...think-1152400/

Is the same year, so am thinking it might be something that went bad with the tach that our cars have in common, I removed a single screw at the end and it went away, but I also lost the buzzer going off when you hit redline. If you decide to foolow mine, confirm that your water and old sensors are still operating too

 

Hi Malic, I read about the screw to back off. Do I take the dashboard speedometer off. I have a few days off this week so I figured I would work on the car.

Thanks, Harold

 

I just ended up removing the screw that had O/R written next to it on the back of the cluster, nothing else was removed.

I would still double check your water level and oil level sensors by pulling it out of the water or grounding the wire to the chassis still to make sure they are still working properly

 

When this happened to me, I discovered it was the water level. . . . .Apparently it's a bitch to get all the air bubbles out.

Don't let the water overflow reservoir run dry. . . .It'll suck air back in.

Check the sensors on the radiator. . . . I believe it is the top sensor that triggers the low level alarm.

 

Hi Malic, I bought a new Radiator sensor and replaced it with the old one. It did not make a difference. I ended up taking the car to a repair person who only works on Mazdas. He found the buzzing noise to be related to the clutch as it was leaking and the master cylinder. He undid the wire to it which made the noise go away.

I appreciate you giving me ideas so I could try and fix it myself. Thank you very much !!!