Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: Donato on February 17, 2004, 01:26:44 PM

Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Donato on February 17, 2004, 01:26:44 PM
Help!!!

I can hear a grinding noise coming from the pulley of the turbo...are the pulley bearings seperate and repacable or am in trouble???:(
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Donato on February 17, 2004, 01:31:49 PM
Not actually sure if its bearings, it seems like there is a plate at the front with metal straps on it thats causing the grinding...
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Joel Kelly on February 17, 2004, 01:41:53 PM
Donato,

That photo in fact shows the air pump. This pumps air into the catalytic converter below certain engine speeds (2700rpm, IIRC) to clean exhaust gasses at idle. I think it may also help purge the combustion chambers at low engine speeds. The grinding noise may be a sign that the bearing, which is known to fail, is on its way out. As this is the case, my recommendation would be to stop using the car completely. If the bearing fails completely, and the pulley locks solid, this can prevent your water pump from operating (aswell as your alternator), leading to serious overheating (and the attendant problems, including water seal failure).

Don\'t worry about your turbos!

I have an air pump which I no longer use, and I would be happy to send this to you for a nominal fee, plus postage. PM if you like. I think that new airpumps from Mazda are very expensive, £300+ IIRC.

Hope this helps,

Joel
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Donato on February 17, 2004, 01:46:54 PM
air pump..:rolleyes: embarrassed!!


Cheers

you will have pm shortly....
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Gman on February 17, 2004, 06:39:47 PM
moved to technical
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: bnaellis on February 17, 2004, 07:46:13 PM
Nothing wrong with the bearing of airpumps on rx7s wearing out.
Most of the nosie you hear at approx 2,500rpm on a rx87 airpump is the noise of it cutting in & out as it hits 2,500rpm.
The only time you have a problem with the bearing is after a long period of use with an aftermarket induction kit. This is because unlike the standrad induction the aftermarket ones pulls in a lot of hot air and it\'s this hot air that after a period of time causes the bearings to be noisy on the airpump. But noise from the airpump when you have an aftermarket induction kit is normal at 2,500 rpm as this is when it cuts out.

rgds
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: mraraju on February 18, 2004, 01:51:00 AM
the price from mazda is 700+vat

Had a quote as mine siezed, had to replace though!!

Raju
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Donato on February 18, 2004, 10:48:05 AM
Quote - (The only time you have a problem with the bearing is after a long period of use with an aftermarket induction kit. This is because unlike the standrad induction the aftermarket ones pulls in a lot of hot air and it\'s this hot air that after a period of time causes the bearings to be noisy on the airpump. But noise from the airpump when you have an aftermarket induction kit is normal at 2,500 rpm as this is when it cuts out.)

Thats exactly the problem by the looks of it. As its got an aftermarket induction kit. But they weren\'t just noisy, this is a metal on metal grinding!! The sort of noise that makes you cringe when you normally have a sweet sounding engine!!:)

I reckon it was close to seizing as by the time i got home last night it was sounding and smelling very bad. The car is now stuck in the driveway until i replace it!! :reallymad
Title: AAAAAAAAAAAAHHHH horribly grinding noise!
Post by: Donato on February 18, 2004, 10:52:14 AM
Whats even worse though is the fact that i did automotive engineering at college 10 years ago, so where i got a turbo with a pulley from (original post) is beyond me :o :o :o

Must stop drinking at the weekend!! :rolleyes: :rollin