98 Z3 convertible motor issues

[dunesend2]

Just a little confused, top will go down with the electric motor once you get away from the windshield. It will not go up, you can hear it working, but NO-GO, you can help it by hand, but most of the work is being done manually....thoughts, where do I start (98 Z3, 28,000 miles)

[deni2s]

Rtfm!

http://www.bmwz3club.fr/site/doc/manuel_Z3.pdf

[Mr Bingley]

Easy answer--disconnect the piston and just do it manually. More complicated answer--sounds like the reservoir is low on hydraulic fluid--possibly a leaky piston--investigate.

[BimmerBreaker]

Actually sounds like normal functioning to me... You unlatch then push away from windshield frame to put the top down or pull towards the frame to close and latch it. That is why latches are manual.

[khammack]

Actually sounds like normal functioning to me... You push away from windshield frame or pull towards to close. That is why latches are manual.

You should not need to pull the top up in order to start it going up.

[dunesend2]

Thanks good start....I'm not against the manual process, the queen not so much

[BimmerBreaker]

You should not need to pull the top up in order to start it going up.

On mine I always pushed away from the frame, once it was "up" the top motor would take it from there. Every z3 Ive seen has been like this, push up a few inches away from windshield before motor catches

[khammack]

On mine I always pushed away from the frame, once it was "up" the top motor would take it from there. Every z3 Ive seen has been like this, push up a few inches away from windshield before motor catches

Same here. I was talking about the post that indicated that you need to lift the top to get it started going up, not down.

or pull towards to close

I may have misunderstood what you were saying.

[BimmerBreaker]

Ah yes that was definitely confusing. I edited it and tried to clarify it a bit...

Either way seems like its normal. Some Z4's have full power tops, with motors for latches and the front hinge in the top... but that just adds more complexity and weight... Z3 top design is beautifully simple

[deni2s]

Z3 top design is beautifully simple

And one of the fastest on the market too.

[Vintage42]

... top ... will not go up, you can hear it working, but NO-GO, you can help it by hand, but most of the work is being done manually...

The power top is supposed to rise by itself without manual assistance. If manual assistance is required to raise the top, not only is something wrong, but you are probably not able to raise the top as fast as if it were freed from the hydraulics. Until the problem is fixed, you can use a little Tee handle on the pump to change to manual operation.
http://www.bimmerforums.com/forum/sh...3#post29228343

[deni2s]

The power top is supposed to rise by itself without manual assistance.

Not entirely correct, as you still have to press the brake pedal...

[dunesend2]

Getting plenty of ideas...let me clarify to better sort the thoughts (1) down cycle, push top away from windshield (about 4"), foot on brake, hit the switch, she lowers....going up, foot on brake, hit the up switch, motor runs, no movement, reach around pull halfway up and it has enough guts to finish the job. I understand its an electro/hydraulic motor, how do you refill hydraulics, bleed if needed, and eliminate this as the issue, thanks in advance

[z3forlife]

Remove the driver (left) side trunk liner and you can see it all

[khammack]

This is where the oil level should be in the pump (from the Randy Forbes collection) ...

[Vintage42]

This is where the oil level should be in the pump...

"The level in this reservoir is *just* below optimum, as noted by the dot in the center of the circle."

[khammack]

"The level in this reservoir is *just* below optimum, as noted by the dot in the center of the circle."

As long as it is in the circle you are fine.

[LannVouivre]

This is where the oil level should be in the pump (from the Randy Forbes collection) ...

Off topic: I want to get a bunch of his photos and have then printed on stuff. I'll call it The Randy Forbes Collection™ and sell it for nonsensical prices.

On topic: if your oil level is low, please check for a leak.

[BimmerBreaker]

Ah yes I totally misread what was happening from OP's post.

I would check the hydraulic ram for leaks. It is located behind the driver's seat towards the outside of the car behind the carpet.

[TheDrip]

My top also needs help when its in the down position. The pump doesn't even run until the top is lifted about 1 inch, otherwise it works fine.

Its almost like its hitting an end-stop switch that stops the pump when the top is all the way down, but this is disabling the pump completely so it won't turn on to raise the top. Lift the top up an inch and the motor runs fine and closes the top.

I haven't had time to try and diagnose the cause, I've just observed the symptoms.

It is a bit of a contortionist act to press the roof-up button and raise the top an inch at the same time, but still handier than having to get out to raise/lower the top in manual mode.

Edit with additional information:

My top switch is broken and bypassed. This switch shouldn't play into the problem when fully closed as far as I know.

[z3forlife]

You must raise the front of the top because there is a safety switch that prevents the motor from running. It's not a "fully" automated top. Raising the front section by hand is normal as far as opening goes. Closing the top should start as long as your foots on the brake. Check the safety switch at the knuckle of the front section it may be the cause of it not wanting to go up

[Randy Forbes]

This is where the oil level should be in the pump (from the Randy Forbes collection) ...

Make sure too that the T-handle for the valve is turned fully clockwise (closed).

In the event that you do want to operate the top manually, turn that same valve handle fully counter-clockwise to bypass the cylinder.

Of course, ALL THAT information is well documented in your owner's manual.

(And thanks Ken, saved me the trouble to look for the picture!)

[khammack]

You must raise the front of the top because there is a safety switch that prevents the motor from running. It's not a "fully" automated top. Raising the front section by hand is normal as far as opening goes. Closing the top should start as long as your foots on the brake. Check the safety switch at the knuckle of the front section it may be the cause of it not wanting to go up

Raising the front of the top is for putting the top down, the OP is having issues with closing the top.

- - - Updated - - -

(And thanks Ken, saved me the trouble to look for the picture!)

Randy, you are all over Google.

[slabhead]

I know this is a rather stale thread, but I feel the need to post my surprising solution to the OPs problem. I had exactly the same behavior: the top would retract fine but would struggle to close/raise. Sometimes it would manage (very slowly) to close but most times it couldn't overcome the first 12" or so. If I helped it start it would close the rest of the way, albeit quite slowly. It was getting pretty bad and I was looking into what parts I might need to rebuild or replace.

As luck would have it, I had to remove the hydraulic pump in order to replace my antenna grommets. This gave me an opportunity to inspect the pump and fiddle around a bit. At first I thought the fluid level was low, but then I learned how to read the level indicator. Spot on, so not a problem with the level and no leaks present. Hmph. So I think "maybe the pump is bad". Out of pure curiosity, I unscrewed the "emergency" release (the T-handle) to allow manual operation of the top. I raised and lowered it a few times just to get the hang of how it operated in manual mode. Then I screwed the T-handle back in and checked the powered operation of the top. Holy crap! Not only did it work, but it was stunningly fast!! Up, down, up down, drive for a while with it down, up, down, up, wife says "quit playing with it, it clearly works".

I have no real idea *what* part of that operation caused everything to start working but I'm thankful I didn't spend the $300 or so to have the pump rebuilt (or worse yet, $1K+ for a new pump). I don't know how long my luck will hold, but for now I'll take the miracle cure. For those of you with this problem, it's an easy thing to try. The biggest pain is pulling out the trunk cover, which is really quite easy.

[cyberman]

the need to post my surprising solution to the OPs problem

Excellent, closing out threads like this are very useful! Thanks Slabhead!