Noise in AWD

cosmo325xi · 01-20-2026, 02:49 PM

Hello Everyone. I have a 2006 BMW 325xi and I have had the trifecta on for a while and the car has been driving fine in RWD. The lights normally pop on as soon as i start driving. The past couple days when I start driving the car instead of the trifecta coming right on, the car makes this scraping nose from the rear and barely moves. It almost sounds like the rear brake is locked up. Once the trifecta comes on and the car is in RWD it drives fine but I hear a clicking noise coming from the rear.

I figured it could be the transfer case actuator as those often go bad but I was thinking the wheel speed sensor could have been culprit the whole time. If the sensor doesn’t work I am debating replacing the actuator motor. (The sensor is easier to do so i did this first just in case lol)

Not sure the best way to diagnose, I put the new wheel speed sensor on tonight and am going to try to drive it tomorrow. I replaced the radiator and power steering reservoir so I need to put new fluid in before driving it. Any insight can help as most people don’t have this clicking and scraping noise issue on the forums.

lookalikehuuh · 01-20-2026, 07:31 PM

It could be a failed wheel bearing as well. In the early cars the rear wheel bearings had a magnetic tone ring that would create a magnetic signal for the wheel speed sensor. If that magenetic tone ring has rusted/failed then your car won't be able to pick up the speed of that wheel.

If it is the wheel bearing DO NOT BUY THE F A G branded one from FCP Euro, they have recently switched to chinese manufacturing and I am now on my 2nd failed unit within 3 months. I recommend going with an SKF or Original BMW one.

cosmo325xi · 01-29-2026, 07:51 PM

That definetly could make sense. Good note on the FCP Euro non BMW ones. Would that make sense that It would only do it in AWD and not read wheel. I put a new wheel speed sensor on it last weekend and it didn’t fix it. I have a new transfer case actuator motor and guibo coming in this weekend I was planning on doing those anyway. Maybe I’ll order a wheel bearing and replace it just to see. Kind of throwing parts at the car lol. I also put a new radiator and power steering reservoir on last weekend. Trying to give the car some love I’ve neglected doing all this stuff for a while.

01-20-2026, 02:49 PM	#1
cosmo325xi New Member 3 Rep 12 Posts Drives: 2006 BMW 325xi E90 Join Date: Feb 2023 Location: Rhode Island iTrader: (0)	Noise in AWD Hello Everyone. I have a 2006 BMW 325xi and I have had the trifecta on for a while and the car has been driving fine in RWD. The lights normally pop on as soon as i start driving. The past couple days when I start driving the car instead of the trifecta coming right on, the car makes this scraping nose from the rear and barely moves. It almost sounds like the rear brake is locked up. Once the trifecta comes on and the car is in RWD it drives fine but I hear a clicking noise coming from the rear. I figured it could be the transfer case actuator as those often go bad but I was thinking the wheel speed sensor could have been culprit the whole time. If the sensor doesn’t work I am debating replacing the actuator motor. (The sensor is easier to do so i did this first just in case lol) Not sure the best way to diagnose, I put the new wheel speed sensor on tonight and am going to try to drive it tomorrow. I replaced the radiator and power steering reservoir so I need to put new fluid in before driving it. Any insight can help as most people don’t have this clicking and scraping noise issue on the forums.
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01-20-2026, 07:31 PM	#2
lookalikehuuh Colonel 1883 Rep 2,177 Posts Drives: 2006 330i, 2007 335i Join Date: Sep 2014 Location: San Diego, CA iTrader: (0)	It could be a failed wheel bearing as well. In the early cars the rear wheel bearings had a magnetic tone ring that would create a magnetic signal for the wheel speed sensor. If that magenetic tone ring has rusted/failed then your car won't be able to pick up the speed of that wheel. If it is the wheel bearing DO NOT BUY THE F A G branded one from FCP Euro, they have recently switched to chinese manufacturing and I am now on my 2nd failed unit within 3 months. I recommend going with an SKF or Original BMW one.
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01-29-2026, 07:51 PM	#3
cosmo325xi New Member 3 Rep 12 Posts Drives: 2006 BMW 325xi E90 Join Date: Feb 2023 Location: Rhode Island iTrader: (0)	That definetly could make sense. Good note on the FCP Euro non BMW ones. Would that make sense that It would only do it in AWD and not read wheel. I put a new wheel speed sensor on it last weekend and it didn’t fix it. I have a new transfer case actuator motor and guibo coming in this weekend I was planning on doing those anyway. Maybe I’ll order a wheel bearing and replace it just to see. Kind of throwing parts at the car lol. I also put a new radiator and power steering reservoir on last weekend. Trying to give the car some love I’ve neglected doing all this stuff for a while.
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