vanillaninja13

OK so I've been hearing this noise from under my hood for at least 2 weeks now and its gotten louder. I only hear the noise when in Drive and my foot is on the brake, when I got my oil changed yesterday I told the mechanic about it and he said the engine and air filter housing shouldn't be shaking that much when at idle. He suggested new spark plugs, I did that and the noise is still there. Any suggestions on what it can be, I have a 2006 Xb Auto transmission. Thanks!!

jbod

i wouldn't worry about this. i have done extensive research on it about it, because of my problem with it. very common on here. one person suggested you could change the motor mounts, but that he did it, and it didn't make a bit of difference. hopefully we are on the same topic here, because mine doesn't get louder. though i do find the hotter it is outside it seems to move even faster. also if the ac is on too.

vintage42

It is not normal. It just began. So something has changed. My 2006 xB 5MT is totally smooth and quiet at idle, but then it is not an automatic. Engines with automatics do tend to shake some at idle in gear, especially with A/C on. But making a noise is not normal.

Is it related to the air conditioner? Is the air box and its connections tight? Is a fuel line rattling against the firewall? Is it the hood rattling and in need of having its rubber bumpers adjusted?
At worst, perhaps a motor mount or damper has broken, but I doubt that would make any noise at idle.

bbstacker7072

I chased a clicking noise in my engine bay off and on for months. My noise turned out to be the fuel vapor solenoid mounted onto the air cleaner housing. I pulled it free and simply let it float by slightly shortening one of the hoses. I don't know what prompted the change, but the air cleaner housing conducted the clicking and I could easily hear it in the car.

taman86

my xa does the same thing with excessive vibration coming into the cabin through the shifter, wheel, and pedals. just replaced the motor mounts and vibration still there. also i was having the same noise under the hood. i opened the hood, put the car in drive or reverse with the e brake on and could visually see the air box just shaking away. put your hand on it and the rattling went away. the plugs were replaced about a year and a half ago so i have just chalked it up to, its always gonna do it. there are no SES or MIL lights on. but once the car is in neutral or park it smoothes out. i almost wonder if its caused by the torque converter

HotBox603

My xB has loud rattling under the hood while I accelerate, I noticed it happened mainly when it was cold amd I was accelerating hard, but now accelerating any time it rattles. This has been going on for a few months. Its off and on, but it happens most of the time. Everything under the hood is stock, I do have a new exhaust system that I installed that rattles a bit when its in drive, but this has been going on longer than ive had the exhaust.

bearsnob

Did you check the wheel covers? Sometimes you can get a small rock in there and it will sound like it is coming from the engine compartment. Maybe when you are driving, the rock doesn't make noise because the wheel is turning fast enough to pin it to the edge of the cover. Then you hit the brake and it starts flying around inside. I know from experience that the '05s are prone to this problem with the stock wheel covers. Drove me nuts the first time it happened. Don't know about the '06s.

If you can't find the cause yourself, have a mechanic take a short ride with you and do what you need to do to reproduce the sound.