Strange Noise - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

00Silver · 11-14-2011, 08:15

2000 Grand Marquis LS 4.6 v8 132k miles....the other night while slowing down to stop at a red light, my car began making a loud humming/buzzing type of sound(almost like a loud refrigerator compressor) somewhere under the hood. I could feel the vibration in the brake pedal and dash board. My wife said it sounded like it was coming from the passenger side, but it felt to me like it was on the driver side. Did this for approximately 10-15 seconds and then stopped right before the light turned green. I was in the middle of traffic so I couldn't get out and inspect it, and of course it wouldn't do it again the entire ride home. The car did not seem to run any different while the noise was there and all my guages remained normal. This car does have the check engine light on because I need an o2 sensor and a new cat. on the passenger side but this noise didn't seem to me as if it would be related to those issues. I had just bumped the steering wheel a little to the left when the noise stopped...not sure if that had something to do with it or not. Anyone else have similar issues?

**R.S.LOGAN** · 11-14-2011, 08:24

Sure it was an engine noise ? Wasn't ABS kicking in for some reason ? or a front wheel bearing , though it should be there all the time if bearing knackered .

**Bert** · 11-14-2011, 08:40

A good code reader can tell you if there was a problem in the ABS. You should find out if there are any other codes besides the O2 sensor too.

00Silver · 11-14-2011, 09:04

Actually, the abs and traction control lights are on...definitely wasn't a wheel bearing. I had autozone, advance auto parts, and pep boys scan the CEL and they all said I needed the upstream o2 sensor and the cat. was bad. Never had the abs light checked(didn't know you could). The brakes on the car feel fine and she rides like a dream. What would cause the abs light to be on? And IF it is the abs that was making the noise, is there anything I should worry about? I drive my 3 month old daughter around in this car all day long so I need it to be safe.

**R.S.LOGAN** · 11-14-2011, 09:57

Could be faulty ABS sensor or sensor wiring . Can also get light on if sensor has dirt / dust /s*** on it , cutting down air gap .

00Silver · 11-14-2011, 10:52

The previous owner changed the wheel bearings...is there a chance he could have not hooked the abs sensors back up correctly, or at all? I've never really had to deal with abs issues so this is new to me. Thanks

**R.S.LOGAN** · 11-14-2011, 11:20

Yes , certainly worth a check at wiring / connections .

00Silver · 11-14-2011, 12:41

Would a bad wire or connection at the sensor cause the noise I described? I'd go out and check them right now but its pouring down rain.

**R.S.LOGAN** · 11-14-2011, 12:45

More likely to cure the the abs and traction control lights / vibration at pedal .

00Silver · 11-14-2011, 13:07

The vibration at the pedal was only present while the humming/buzzing noise was present...didn't feel like a brake vibration, but more like a cell phone type of vibration which was felt throughout the car. It continued while stopped at the red light and the car wasn't in motion. When the noise stopped, so did the vibration. Think of the sound/vibration the electric fan makes..now imagine that amplified by 5. Thats about the best description I can give. It didn't seem like the car was going to die or anything but it was loud and sounded like something electronic. I haven't been able to get it to repeat the noise as of yet, and its only done it that one time.