hello people. Wondered if anyone could shead any light on this for me...?
I have just started getting a Bussing noise from what sounds to be from the rats nest/intake area deffionatly under the bonnett!
The noise only starts bussing when the car has warmed up.
The noise only Makes the noise when you start the car up.
The noise only last for about 2 minutes
The noise goes after 2 minutes but if the car is re-started it comes back for another 2 minutes.
The noise dosent affect any peformance of the car.
The noise is a constant flat done buss and only starts bussing when the car is started.
but not as scary and loud as the low coolant busser from the dash.
please help what it could possibly be! thank you.
Probably a broke vac line whistling under the plenum.
Shaun
yep, i\'d say the same as shaun. Or a one way valve, these are fairly easy to check, just buy replacement hose before you try, so you can replace the hoses you snap (assuming you still have the stock mazda ones). To check them pull the the hose off each end to remove them (only do 1 at a time and remember that the arrow points toward the UIM), then blow the way the arrow points, then try and suck, if you get air when you suck it\'s knackered and needs replacing.
Or someone could have swapped your engine for one of them bus engines, thats why its a bus noise?
just had new viton check valves fitted! and why would it only do it when the engines warm? then suddenly stop buzzing after about 1 minute? then if i turn the car off and start it back up immediately it will start buzzing again for another minute! and if i hit the gass it dosent get any louder which tells me its not split pipe and it sounds more of an electric buzzing noise. remember the time it starts buzzing when i start the car up.
There are a couple of solenoids that control stuff once the engine warms up (such as the secondary throttle body) and the vacuum may only be present in the broken line at a warm state.
Shaun
well i did remove the buterflys out of the inlet and then bypassed the solenoid into the black box which bolts to the throttle body under the plenum with the two 10mm bolts and put the check valve in the middle of the inlet and the black box which bypassed the solenoid. could this be an issue??
heres a copy of the vac diagram :
http://www.mazdarotaryclub.com/forums/attachment.php?attachmentid=9467&d=1110880632
I think your best just capping it off after the solinoid but I\'m not completely sure. Its the only line left on my car now (gone to a single turbo setup).
Shaun
Just for the record if any1 encounters this issue. I replaced this single solenoid and the buzzing noise from behind the plenum has stopped :) i think the buzzing noise was coming from the ISV which has a red sticker on it half plastic half metal.
(http://i22.photobucket.com/albums/b322/nukinukinuki/vacuum_hose_diagram.jpg)
Thanks.