Power Top Not Working

PrinceMiro · 10-06-2010, 10:31 AM

I'm almost sure there's a thread about a busted power top, but I'm at work and don't have the time to look for it. Although the thread discusses changing the motor, I haven't seen anyone with the same problem as mine. Everyone says their motor is shot, but what does that mean exactly? When I press the "down" button, the roof unlatches normally, but the top doesn't go down. However, the motor is still making its normal buzzing sound as if it was working. I then push the top down manually and continue pressing the "down" button and the top locks in the down position.

Now I thought I would need to replace the motor, but then I found out the the motor is a pneumatic motor. So isn't it possible that the motor is fine and the problem is with one of the hoses connected to the motor? The only reason I ask is because of the normal buzzing sound the motor makes. I would really appreciate some help with this. Thanks everyone.

Spaceman Spiff · 10-09-2010, 04:38 PM

I had that exact same problem with mine. My top would unlatch and the motor would make the normal noises but I had to lower the top manually and then let it latch automatically. The motor is hydraulic as far as I know. I ended up changing the entire top assembly complete with motor after 2 dealers gave me vague/contradictory diags. Once the top was off the car I noticed what looked like a small leak from one of the connectors in the hydraulic oil line. That could have been the reason but you can't know for sure unless you remove the top and trace the lines.

Edit: Shipkiller has a great write-up if you decide to remove the top.

Shipkiller · 10-09-2010, 09:13 PM

PrinceMiro,

The motor is not pneumatic, but hydraulic.

Look at the two threads in the How-To section to see how to remove the top and to replace the motor.

Here are the links for the PDF's of the procedures.

http://www.shipkiller.com/How%20to%2...20BMW%20Z4.pdf

http://www.shipkiller.com/How%20to%2...op%20Motor.pdf

Sorry it took so long to respond, but I am in Honolulu, HI at the moment...

wasupdu · 10-09-2010, 09:17 PM

Although very unlikely, it's worth checking the latch in the trunk. I've had the trunk stuffed before and something accidentally hit the latch back there that prevents the top from going up/down.. Almost certainly not the problem you're having, but at very least it's worth checking.

Shipkiller · 10-09-2010, 09:23 PM

If the latch in the trunk was not making, then the front latches will not unlock.

This is one of the first interlocks that the Soft-Top module uses to start the process.

The rear latch was the very first issue I had with my top, before the motor gave out. The actuation arm had fallen off. Nothing worked when I pressed the button. I jumpered out the switch and the top worked. That rear switch is $35.00 from BMW..

10-06-2010, 10:31 AM	#1
PrinceMiro Lieutenant 39 Rep 407 Posts Drives: z4 3.0i Join Date: Apr 2008 Location: CNJ iTrader: (3)	Power Top Not Working I'm almost sure there's a thread about a busted power top, but I'm at work and don't have the time to look for it. Although the thread discusses changing the motor, I haven't seen anyone with the same problem as mine. Everyone says their motor is shot, but what does that mean exactly? When I press the "down" button, the roof unlatches normally, but the top doesn't go down. However, the motor is still making its normal buzzing sound as if it was working. I then push the top down manually and continue pressing the "down" button and the top locks in the down position. Now I thought I would need to replace the motor, but then I found out the the motor is a pneumatic motor. So isn't it possible that the motor is fine and the problem is with one of the hoses connected to the motor? The only reason I ask is because of the normal buzzing sound the motor makes. I would really appreciate some help with this. Thanks everyone.
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10-09-2010, 04:38 PM	#2
Spaceman Spiff Captain 86 Rep 847 Posts Drives: R8, 996 C2, Z4MR (sold) Join Date: Aug 2007 Location: SF Bay iTrader: (1)	I had that exact same problem with mine. My top would unlatch and the motor would make the normal noises but I had to lower the top manually and then let it latch automatically. The motor is hydraulic as far as I know. I ended up changing the entire top assembly complete with motor after 2 dealers gave me vague/contradictory diags. Once the top was off the car I noticed what looked like a small leak from one of the connectors in the hydraulic oil line. That could have been the reason but you can't know for sure unless you remove the top and trace the lines. Edit: Shipkiller has a great write-up if you decide to remove the top.
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10-09-2010, 09:13 PM	#3
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	PrinceMiro, The motor is not pneumatic, but hydraulic. Look at the two threads in the How-To section to see how to remove the top and to replace the motor. Here are the links for the PDF's of the procedures. http://www.shipkiller.com/How%20to%2...20BMW%20Z4.pdf http://www.shipkiller.com/How%20to%2...op%20Motor.pdf Sorry it took so long to respond, but I am in Honolulu, HI at the moment...
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10-09-2010, 09:17 PM	#4
wasupdu Lieutenant 24 Rep 413 Posts Drives: Z4 3.0, CLS63 AMG Join Date: Jun 2007 Location: Milwaukee, WI iTrader: (0) Garage List 2013 Mercedes CLS63 ... [0.00] 2005 BMW Z4 [0.00]	Although very unlikely, it's worth checking the latch in the trunk. I've had the trunk stuffed before and something accidentally hit the latch back there that prevents the top from going up/down.. Almost certainly not the problem you're having, but at very least it's worth checking. __________________ 2005 BMW Z4 Roadster 3.0 - Black Sapphire with Red Extended Leather / NAV / Premium & Sport Pkgs / 19" wheels / M steering wheel / Xenon 2013 Mercedes CLS63 AMG
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10-09-2010, 09:23 PM	#5
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	If the latch in the trunk was not making, then the front latches will not unlock. This is one of the first interlocks that the Soft-Top module uses to start the process. The rear latch was the very first issue I had with my top, before the motor gave out. The actuation arm had fallen off. Nothing worked when I pressed the button. I jumpered out the switch and the top worked. That rear switch is $35.00 from BMW..
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