Random Low Speed Grating Noise

[Rob]

hi all, noticed today whilst crawling in low speed traffic ( 10 - 15mph) i was getting a random grating noise, couldnt really tell where it was from tho. Best description is an underbody tray scraping on the road or a wheel liner rubbing.

Just wondering if anyone else has had something similar before i start looking at mechanical components

Its not an under tray or liner.

oh - it only does it at low speeds BTW.

ta rob.

[P38Aaron]

I have had something like this, it was the guard behind the brake disc rubbing on the disc, only really heard it at low speeds, solution, bent it away from disc.

Are all your belts in good condition?

[Rikos]

Sounds to me like it could be brakes rubbing.

I'd check these first if i was you.

[Rob]

thanks 4 replies but its def not brakes or the spash guards - as i said its more like an underbody tray or a traffic cone dragging. I suspect its a mechanical fault to will start isolating parts

[Rikos]

You've not ran anyone over recently have you?

[Rob]

haha, no not this month!

[Rob]

i disconnected the compressor and the noise isnt there at the moment but its a random noise so it may or may not be the SC - I hope not!

EDIT: i had a good look at the drive pully and noticed that i could turn the pulley seperatly from the black plastic cover - turning the cover turned the compressor - turning the pully didnt!

I then saw that the 3 screws on the cover plate were missing. I had a quick chat with Gord earlier in the evening as he had a compresspr recently that had a loose drive nut and cover plate with the result it sounded like a bag of spanners, mine had been making a slight noise recently but i put it down to backlash in the gears.

I have yet to take the cover plate off and have a good look but hopefully the noise was down to the pully drive catching and being driven for a few split seconds - that might also explain why i thought the car was down on power

[Gord]

i disconnected the compressor and the noise isnt there at the moment but its a random noise so it may or may not be the SC - I hope not!

EDIT: i had a good look at the drive pully and noticed that i could turn the pulley seperatly from the black plastic cover - turning the cover turned the compressor - turning the pully didnt!

I then saw that the 3 screws on the cover plate were missing. I had a quick chat with Gord earlier in the evening as he had a compresspr recently that had a loose drive nut and cover plate with the result it sounded like a bag of spanners, mine had been making a slight noise recently but i put it down to backlash in the gears.

I have yet to take the cover plate off and have a good look but hopefully the noise was down to the pully drive catching and being driven for a few split seconds - that might also explain why i thought the car was down on power

If you lost the 3 screwa Rob, then that will be the problem :winky: All will be clear when you take to bits and have a look inside mate :D

[Rob]

hi mate i have to get some pins or a few bolts in the front and re install the belt or get a strap wrench to remove the central bolt I will then be able to look inside, but i can already see 2 bolt holes are damaged so I will have to enlarge and rethread the holes anyway. To do it properly Ill remove the supercharger so it gives me the chance to have a good look at the unit and while its out ill check the oil but norm its a sealed unit.

I made a quick post telling people to check the 3 screws.

Gord: any chance u can take a pic of the screws so I can have a look around for something of the same length??

[Gord]

hi mate i have to get some pins or a few bolts in the front and re install the belt or get a strap wrench to remove the central bolt I will then be able to look inside, but i can already see 2 bolt holes are damaged so I will have to enlarge and rethread the holes anyway. To do it properly Ill remove the supercharger so it gives me the chance to have a good look at the unit and while its out ill check the oil but norm its a sealed unit.

I made a quick post telling people to check the 3 screws.

Gord: any chance u can take a pic of the screws so I can have a look around for something of the same length??

Sure Rob, send me you email address.

[Rob]

pm on its way!

[Moffet]

he had a compresspr recently that had a loose drive nut and cover plate with the result it sounded like a bag of spanners

Was this mine, Gord? I was wondering if you found out what was wrong with it!