Leading Rotarian

Recently, when I drive over the crest of a hill in my 85 RX7 at legal road speeds in my area (35 - 55 mph) I hear a sound that sounds like it may be a tire rubbing or the fan hitting the shroud. It only happens when I am traversing the crest if the hill and the G-lpad is going negative. The car is bone stock, including the stock 13 inch wheels. The car runs and sounds fine otherwise.

Mr_Miles

iTrader: (1)

if I'm understanding you right, it only happens when the car hits the top of the hill, when it feels like there is less gravity?

Try jacking up the rear of the car, but only the body. so that way your tires are still on the ground. start the car. see if it does it. the only thing i can imagine is that when you hit that point, what's happening is its pulling down on the back of the transmission and causing the fan blades to hit the shroud.

Leading Rotarian

I was thinking worn mounts myself

Mr_Miles

iTrader: (1)

Mhm, that's what I was figuring. have you tried moving the motor around by hand? see if you can make it flop around a unreasonable amount.

rxtasy3

iTrader: (2)

try this. get the rear of the car in the air and put stands or something under the body to hold it. start the engine and put it in gear so the rear tires r turning. if letting it idle doesn't work get a friend to hold the rpm's up and get the speed up. then lower the rear end down til it starts making that sound and investigate what's causing it.

DivinDriver

iTrader: (15)

Check the inside top of your fan shroud for scuffing. That'll narrow down your search.

Bad motor or trans mount could be the culprit. You also may just have a really noisy bushing in the suspension - - try bouncing the front an rear by hand with the engine off.

wankelnewbie

iTrader: (2)

You might also look at the plastic fender wells around the front wheels. If a couple of those little plastic fasteners have broken off, the fender well may be hanging a little too close to the wheel, and when the front end is unloaded and the LCA pulls the wheel in, it may be rubbing. Easy to check, and hopefully fix.

Also see if you can lift the radiator by hand. GL!

mazdaverx713b

iTrader: (91)

look for wear spots on the tires and the wheel wells. this will tell you if a tire would be rubbing. look at the fan and shroud. see if the fan is scuffing the shroud. if it is you will see black plastic and markings on the tips of each fan blade.

if the engine mounts are that bad that they are allowing your engine to sag, then you have a serious problem with them. i have never seen an engine mount sag..usually they just break. also, the engine shouldn't move rearward due to the rigidity of the drivetrain. if a mount were bad the engine would just rock upwards and downward.

Leading Rotarian

No marks around wheels, on liners or on tires themselves.