Loud 'humm' when lifting off...
09-03-08, 09:26 AM
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got teh rotorz?
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Location: Brighton, UK
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Loud 'humm' when lifting off...
Hi,
This is my second 'odd noise' thread today...!
To recap, its a '94 Type R, on stock twins, running a possibly lightly ported engine... manual gearbox. (~300fwhp)
In addition to the grinding noise i'm getting in this thread, I'm getting a loud humming noise when lifting off the accelerator....
Its not 'moo'ing' like what happens with no airpump... its a loud humm (not sure how to explain it LOL) and vibrates too.
When the engine is under load, the noise is NOT there, if you lift of the accelerator pedal just enough to remove the load from the engine, but not lift off completely, the noise starts. If you lift off completely, the noise is still there, but is masked a bit by the exhaust noise/ engine-breaking noise (or overrun or whatever its called).
I've had a full geometry check done and wheel alignment and all is fine. Though there is also a slight vibration coming through the gearstick, though not sure if this is related to my other post about the grinding noise, or because I have solid engine mounts.
No idea what it could be, but I'm suspecting that (possibly unrelated) that my cat might be blocked / disintegrating and that my air pump is on its way out...
(also note that the aircon is still fitted).
Pleeease help
MORE INFO ON CAR:
Its got a big FEED intercooler, stock twin oil coolers, Apexi 8bit Power FC (no commander)... It was mapped by a very good UK mapper when it came over, to a nice and safe 300fwhp.
A bit of history...
Car was imported into UK from Japan in 2006, having had an engine rebuild and map by FEED in Japan.
It had about 5,000Kms on the new engine, and has now done an additional ~10,000Kms.
(total of about 60,000MILES in total on odometer, though the chassis, electrics and shell are about the only original things on the car right now!)
It looked and drove fine when I bought it, but I've since had to get a lot of repair work done on various bits cos I think it had been thrashed in Japan...
I have :
Replaced old 1.5way Kazz diff with stock Mazda diff (low mileage)
New clutch (Exedy Organic single plate)
Rebuilt gearbox
New Tein Super Street coilovers
Replaced turbo pack (stock)
Got a FEED downpipe, stock cat, large back box.
Solid engine mounts
This is my second 'odd noise' thread today...!
To recap, its a '94 Type R, on stock twins, running a possibly lightly ported engine... manual gearbox. (~300fwhp)
In addition to the grinding noise i'm getting in this thread, I'm getting a loud humming noise when lifting off the accelerator....
Its not 'moo'ing' like what happens with no airpump... its a loud humm (not sure how to explain it LOL) and vibrates too.
When the engine is under load, the noise is NOT there, if you lift of the accelerator pedal just enough to remove the load from the engine, but not lift off completely, the noise starts. If you lift off completely, the noise is still there, but is masked a bit by the exhaust noise/ engine-breaking noise (or overrun or whatever its called).
I've had a full geometry check done and wheel alignment and all is fine. Though there is also a slight vibration coming through the gearstick, though not sure if this is related to my other post about the grinding noise, or because I have solid engine mounts.
No idea what it could be, but I'm suspecting that (possibly unrelated) that my cat might be blocked / disintegrating and that my air pump is on its way out...
(also note that the aircon is still fitted).
Pleeease help
MORE INFO ON CAR:
Its got a big FEED intercooler, stock twin oil coolers, Apexi 8bit Power FC (no commander)... It was mapped by a very good UK mapper when it came over, to a nice and safe 300fwhp.
A bit of history...
Car was imported into UK from Japan in 2006, having had an engine rebuild and map by FEED in Japan.
It had about 5,000Kms on the new engine, and has now done an additional ~10,000Kms.
(total of about 60,000MILES in total on odometer, though the chassis, electrics and shell are about the only original things on the car right now!)
It looked and drove fine when I bought it, but I've since had to get a lot of repair work done on various bits cos I think it had been thrashed in Japan...
I have :
Replaced old 1.5way Kazz diff with stock Mazda diff (low mileage)
New clutch (Exedy Organic single plate)
Rebuilt gearbox
New Tein Super Street coilovers
Replaced turbo pack (stock)
Got a FEED downpipe, stock cat, large back box.
Solid engine mounts
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