[cadman50]

I brought my 2012 X3 35i in to the dealer for some warranty work. Nothing big I thought. Brakes, wipers and a subtle engine idle fluctuation. Sometimes when i'm waiting at a light or in Park and the engine is just idling, the engine seems to vibrate like it's misfiring or not getting gas. They have had it now for several days and can't seem to find out why. They are in contact with BMW engineers and have opened up a case with them. Geez I didn't think it was that big a deal but I wanted to get it fixed before the warranty runs out in 5K miles. Has anyone had this issue? They have checked the obvious.
On a side note, I had an X1 for 3 days. Didn't like it. So I was able to change over to an X3 28i. I was pleasantly surprised at how the 4 cyl turbo handled and drove. I still like my 35i though. Also, i have DHP with worn tires. The loaner has the same tires (19") although they are newer and the ride is ok. When i get mine back I'm going to immediately compare how the ride is. I can't imagine the loaner has DHP but it seems to give a decent ride. Of course the loaner is newer with newer tires and suspension so it might be a hard comparison. One last thing. I upgraded my audio. The loaner has a respectable audio with the standard audio. I was also surprised at that.

[The X Men]

Definitely get it sort out before the warranty expire, it might be something serious like a fuel pump. I had a X1 MSport loaner, it was a lot of fun to drive. The steering was well connected and feels like a BMW of yester-year. Comfort and tech wise, I prefer the X3. Tires can make a world of difference in ride and handling. If you have GY eagle LS2, those tires are horrible once they start to wear down half way. The standard audio sound ok when low, try turning it up and you will realize how under power it is.

[epiphone3]

definately keep us posted on the engine idle fluctuation. I've had mine do that to me once and some times it feels like it shakes a bit right after a start up. Curious if they find anything with yours... mine runs perfect so I haven't worried about it at all.

[cadman50]

i think I'm getting my car back tomorrow. They replaced a engine temp sensor that they (and BMW engineers) feel might be the culprit. But they also performed other tests too including something with the exhaust system. No mention of a fuel pump which is kind of surprising. I'll see when I get it back. Also to compare the X3 28i loaner with my X3 35i.

[02420X3]

Cadman, while you're still under warranty, ask them if there are any stored low voltage codes on your battery. In fact, why not ask them if there are any other stored codes at all which they didn't mention. My dealer mentioned low voltage codes on my X3 on the first out of warranty service visit. I held off, but just came home from a 2-week trip to a battery warning message. List price on the battery for the OEM 35i is over $300, plus labor to install and register the battery. You'll find extensive discussions elsewhere on whether or not an OEM battery is necessary, and if registration of a new battery is necessary.

[cadman50]

Apparently they ran diagnostics for code violations and nothing came up. But I'll ask them about the battery when I pick it up. What's the purpose of registering a battery? If my battery goes then I would have just gone to Sears or another place to replace it. Is there something special about a BMW battery?

[02420X3]

BMW says that the registration, a software process, is required. Some agree with that, and some dispute it.

Take a look at your battery. There are more cables attached than the standard POS and NEG, and then there is the venting. If I were to have a battery replaced by someone other than the dealer then I would at least go to a good indy shop, rather than Sears or a parts supply house.

[cadman50]

Originally Posted by 02420X3

BMW says that the registration, a software process, is required. Some agree with that, and some dispute it.

Take a look at your battery. There are more cables attached than the standard POS and NEG, and then there is the venting. If I were to have a battery replaced by someone other than the dealer then I would at least go to a good indy shop, rather than Sears or a parts supply house.

I didn't know that. thanks for the tip.