weird bump noise

[smOKeSILVER13]

While my car is at idle I can hear and barely feel a bump pause bump pause, like there is a windshield wiper on almost. Any ideas?

[Pagz]

just guessing,maybe your engine mounts are up for renewal,and the engine has a slight rough idle.

[zac]

I just bought a 96 c36 that does the same thing. Whatever it is is up in the passenger side of the engine compartment near the firewall. Definitely not the engine mounts. Some sort of cylinder, I doubt it's the brakes though. I haven't gotten a chance to buy any sort of repair manual yet. Sometimes it does it, sometimes (like when I test drove it and when I took it in for an inspection) it doesn't.

[Pagz]

dont cancel out the engine mounts...they may look alright,but if they have crushed down 10mm like almost all eventually do,then you will feel every uneven beat of the engine...like the feeling of the window wiper...

[Pagz]

Originally posted by zac
I just bought a 96 c36 that does the same thing. Whatever it is is up in the passenger side of the engine compartment near the firewall. Definitely not the engine mounts. Some sort of cylinder, I doubt it's the brakes though. I haven't gotten a chance to buy any sort of repair manual yet. Sometimes it does it, sometimes (like when I test drove it and when I took it in for an inspection) it doesn't.

hmmm,sounds like the MOT valve...everybody has this noise if it is

[smOKeSILVER13]

Originally posted by zac
I just bought a 96 c36 that does the same thing. Whatever it is is up in the passenger side of the engine compartment near the firewall. Definitely not the engine mounts. Some sort of cylinder, I doubt it's the brakes though. I haven't gotten a chance to buy any sort of repair manual yet. Sometimes it does it, sometimes (like when I test drove it and when I took it in for an inspection) it doesn't.
That's exactly where the sound is coming from on mine.

[Pagz]

LOL have you opened the bonnet and attempted to pinpoint it?

[c280nz]

i think its the heater valve pulsing.
you can only feel it when the car is at idle? myne does the same? put the heater onto full hot and see if it stops, that would pin point it. so it depends on what temperature you have it on, when the temp is set only slightly hotter than the outside temp

i beleive they pulse open and closed to check temperature?
my car is right hand drive so i can feel it tap through the foot pedals at the traffic lights, bit annoying but i ant gona worry bout changing them as i think the new ones will do the same

[smOKeSILVER13]

Originally posted by 23K
LOL have you opened the bonnet and attempted to pinpoint it?

Of course.

[Pagz]

Originally posted by c280nz
i think its the heater valve pulsing.
you can only feel it when the car is at idle? myne does the same? put the heater onto full hot and see if it stops, that would pin point it. so it depends on what temperature you have it on, when the temp is set only slightly hotter than the outside temp

i beleive they pulse open and closed to check temperature?
my car is right hand drive so i can feel it tap through the foot pedals at the traffic lights, bit annoying but i ant gona worry bout changing them as i think the new ones will do the same

yo,
Is that the twin valves residing infront of the brake cylinder?

[c280nz]

i beleive so, i feel myne tapping through the clutch pedal when im resting on it at traffic lights

[Pagz]

hmmm weird,iv never noticed that on mine...
maybe i need 6 cylinders:D

[c280nz]

...or a more sensitive foot ;)