Hi my 2007 328i Bmw SHAKES when i start my car does anyone have any ideas why? I took it to the dealer to get a diagnostic and they told me i need to get my o2 sensor replace and it going to cost me $650. Is this the reason for the shaking the O2 sensor?

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW 3 Series (E36) Oxygen Sensor Replacement

Yikes, that's way too much - you can do it yourself for much cheaper. Although, there are indeed four on the car, perhaps they are trying to get you to replace all of them. As for the car shaking, it shouldn't have anything to do (in my opinion) with the O2 sensor. Could be something else, like a vacuum leak. It could be related to an O2 sensor, but I find it unlikely - most of the time O2 sensor problems make the car run rich or lean, not necessarily shake.

- Wayne

02 sensors have nothing to do with strart up. They don't even kick in until the car warms up. How many miles are on the car? The O2 sensors usually last the life of the car or at least 100k!! The chances of all four going out simulatenously on a car as new as yours is about as same as finding a palm tree on top Mount McKinley.

Even if they did replace all four it would not solve your problem. I gave up on local BMW dealers here. Once, I had a brake light switch go out and they told me
I needed a new transmission. Another time they told me that I could not replace the little tiny bulbs in my On Board Computer, I would have to buy a whole new unit for a grand. So I needlessly bought an aftermarket radio so I could have a clock only to find out that I could have fixed it with a $1.50 bulb!!!

Car Dealerships are PROFIT CENTERS!!!! they profit from you. Ironically you don't find the best mechanics at dealerships. Most dealers hire new tech school grads who usually leave after two to five years and start their own shop or move to a specialty shop where they can make more $ and do more challenging things.

not a solution, but
 

some of the '90's e36es would run rich and shake at re-start if:
engine was shut down within a minute/or two of a cold start and restarted.

my '94 does this and always has.
so, i don't do that.
my theory is that too much fuel is left unburned and so runs too rich at re-start. experts 'might say' i have an injector gasket leak or something similar.