1988 mazda rx7 se

only when cold outside, before it is totally warmed up, it sounds like there is a really lou blower noise as i go through the gears. then if i shut the car off when it is totally warmed up, and start it again, it doesnt do it...is that just an accelerated warm up process?

 

You're probably going to have to give us more than that, like where's it seem to be coming from? What exactly does it sound like? When does it occur (always, only at WOT, only around shifts...)? It's hard to say right now. Just tell us all you can. Also, if you can get video with sound posted up here that will probably help a lot.

 

It could be your radiator fan clutch not disengaging. I wouldn't worry about it if that's it. As long as it disengages after warming up...

It's a viscous clutch, so it is affected by temperature, especially after 20 years of service.

 

Well that was my first thought, but I wasn't sure because it's supposed to grab more as it gets warmer *shrug*. I'm not saying it isn't the fan. And as anecdotal evidence sometimes my fan will spin up when I start the car and then it takes a break before long and reengages when it's actually supposed to. I never noticed it doing much while I drive, but I'm not under the hood watching it and my exhaust is probably much louder than anything the fan could do...

 

Mine does the exact same thing and it's the fan clutch, but you've got a good point. It's counter intuitive.

It grabs as it gets hotter because there is a bi-metal strip (bends as it gets hotter) that pushes the viscous clutch clearance closer.

I think what happens as the clutch gets older is that the oil inside degrades and loses the properties it had when new. It might form waxes and thicken, but that's just a guess.

 

yeah it was me asking the question on my buddies account, it does it only when it is uber cold outside, or when it is just warming up...unless it is like 0-10 degrees outside, it usually goes off after the car is warmed up, but if it is "death" cold outside then a few times it has stayed on. so i guess i wont worry too much about it...today it was in the lower 20's, and it didnt do it at all.