vanhoozj
New member
- Joined
- Nov 9, 2017
- Location
- North Carolina
I?ve got an 86 240 that is making a noise from behind the center console by the center vents. I?m not sure it?s the blower motor but wanted to see if anyone here has had a similar experience before I go that route.
To me it?s sounds more electrical vs mechanical; like the dull spinning noise of a motor being turned by hand almost a grinding or growling kind of thing. The sound begins when I am up to roughly 20-25 mph and air is coming through the vents even with the blower in the off position. I know airflow in the off position is partially by design with the A/C system.
The noise increases in speed as I accelerate and airflow through the vents also slightly increases. The noise goes away when the car is at a slow enough speed and airflow decreases as I decelerate. Once stopped there is no air flowing through the vents and no noise, again all of this is while the blower is in the off position.
The blower fan works in all positions and has no effect on the sound. I?ve pressed in the recirc button to attempt to eliminate airflow into the air box from the cowl and it doesn?t affect the sound either. The noise remains both while recirc is engaged or disengaged.
My initial thought was that somehow air is passing through the firewall and spinning one or both of the impeller fans causing the motor to rotate; therefore, making the noise. I can?t see anywhere that air is getting into the firewall as all the grommets look intact and sound.
I?ve also checked for exhaust leaks as a trusted mechanic suggested. The car has a larger exhaust than stock and a larger cat, but no luck isolating the noise to a leak.
Another mechanic simply said it's the blower motor but the motor operates fine at all speeds, no noise when I?m idling or under 20mph and this noise occurs even with the blower in the off position again at higher speeds so I?m just not sure that?s the issue.
Any suggestions?
To me it?s sounds more electrical vs mechanical; like the dull spinning noise of a motor being turned by hand almost a grinding or growling kind of thing. The sound begins when I am up to roughly 20-25 mph and air is coming through the vents even with the blower in the off position. I know airflow in the off position is partially by design with the A/C system.
The noise increases in speed as I accelerate and airflow through the vents also slightly increases. The noise goes away when the car is at a slow enough speed and airflow decreases as I decelerate. Once stopped there is no air flowing through the vents and no noise, again all of this is while the blower is in the off position.
The blower fan works in all positions and has no effect on the sound. I?ve pressed in the recirc button to attempt to eliminate airflow into the air box from the cowl and it doesn?t affect the sound either. The noise remains both while recirc is engaged or disengaged.
My initial thought was that somehow air is passing through the firewall and spinning one or both of the impeller fans causing the motor to rotate; therefore, making the noise. I can?t see anywhere that air is getting into the firewall as all the grommets look intact and sound.
I?ve also checked for exhaust leaks as a trusted mechanic suggested. The car has a larger exhaust than stock and a larger cat, but no luck isolating the noise to a leak.
Another mechanic simply said it's the blower motor but the motor operates fine at all speeds, no noise when I?m idling or under 20mph and this noise occurs even with the blower in the off position again at higher speeds so I?m just not sure that?s the issue.
Any suggestions?