When I start up my '85 -SE, I get a dull buzzing noise that sort of drowns out the sound of the engine. I'm not sure what this means, maybe it just needs to be driven around a while. I haven't driven it in about a week. Recently the oil cooler was changed (was modified to fit a second gen FMOC), and the A/C was taken out. I'm not sure if that has anything to do with it. Either way I'll be taking it into a Mazda shop in a couple weeks, I was just wondering if anyone knew what this might be so I could read into it.

 

your cars done for. ill come take it off your hands for 30 bucks.

 

Might be the oscillator, unplug the little black electrical box up behind the driver's side headlight to see if it stops. If so usually just a little cleaning of the connections will fix it.

 

Ray, what does the oscillator do, besides oscillate? What is its purpose?

 

Do a search Jeff. Just kidding.

Actually I've asked the same question and I have done a search but I couldn't find the answer.

I think it has something to do with some of the warning buzzers so it is probably a good idea to have it hooked up, especially if you are not in the habit of checking your fluids. But the car runs fine without it, a lot better in fact without that screeching sound (my dogs still won't get in the car with me).

But it happens a lot when the weather turns cool and damp, another clue (I just got my fist reoccurrence in more than a year just last week, on a cool morning after I had given the engine bay a bath).