Z4 E89 / 3er E93 / 4er F33/F34 -Urgent recommendation to replace the hardtop relais

[RobbiZ4]

Originally Posted by Wan186

I thought about that too. But let's clarify: here is the workshop & repair manual:
The relays should have be opened before the pump was dead...
----------
By the way, on the video, the relays is tagged 13A...
When i see salmon relays (exact same OEM reference) tagged with 73A.
Wtf?

RobbiZ4 How much your ones was tagged?

The temperature in the hydraulic pump is measured to avoid the pump
overheating during frequent use of the retractable hardtop. Two cables connect
the temperature sensor ground-free to the convertible top module. A line break
(open circuit) results in a fault code being entered in the fault code memory. At
from a temperature of 90°C, hardtop closing movement already started is
continued up to the secure end position. The movement of the retractable hardtop
is stopped immediately at a temperature of 105°C.

The above text out of the E89 roof documentation was taken out of a Rosamunde Pilcher lovestory roman: sounds nice, but is far apart of real life!

Out of my initial post
[...]
The following link is not required to read! It will lead you to the backgrund story and the "why" did we discuss and analyze this topic.
http://www.zroadster.com/forum/index...raulik.133304/

The temperature is ONLY managed while the CTM (Cabrio Top Module) is active and opens or closes the roof (about 45 seconds). Then it shuts down and doesn't control any sensor anymore. If a relay contact melts/doesn't open anymore, the pump will run uncontrolled until it dies.

Have a look at my EGK diagram in the above named basic thread. Use Google translate, as it's in German!

EKG diagnostic sequence of the temperature sensor while the roof is moving:
[part1 - start]


[part 2 - shut down]



Till now I didn't find any infos about this "13A" or "73A" marker. It's different on most relays I've seen in the past and in pictures of the currrent discussions. It's AFAIK of no interest, migtht be a production info.

The second marker ist the production date of the relays: 0911, 1234, 1622 means week 11/2009, week 34/2012, week 22/2016 in the format of [YY/WW].


All further discussions and updated infos on the German ZROADSTER.COM forum as well as on the here blocked "spool street".com forum.

[Wan186]

Oh, I was replying to the previous guy about why you're story was true. Aka: the relays should have be opened but as they're stuck, they don't.

I readed the whole story for sure. Good job guy.

Was talking about this tag cause usually, the max amperage is tag on the relay. Since there was many providers for BMW for this relay (Siemens, Bosch, ngk, and now Tyco aka TE), I was thinking that maybe this last one is weak...

[rjahl]

Originally Posted by Wan186

Oh, I was replying to the previous guy about why you're story was true. Aka: the relays should have be opened but as they're stuck, they don't.

I readed the whole story for sure. Good job guy.

Was talking about this tag cause usually, the max amperage is tag on the relay. Since there was many providers for BMW for this relay (Siemens, Bosch, ngk, and now Tyco aka TE), I was thinking that maybe this last one is weak...

I don't feel that replacing a underrated or deficient design with another replica is a solution. Relays are not voodoo science. If we are assuming the points are overheating and melting closed, either the relay was defective or it's being asked to handle more load than it was designed for. Relays should work for thousands of cycles without any issue. I'd rather correct the reason for the failure.

I'm still not 100% convinced that an aging motor could not draw excess current and overload the relay. We are mainly looking at the starting current when the relay closes. That spike is usually too quick to blow a fuse but can be high enough to damage contractors.

Does anyone know the actual motor load and current rating on the relay?

[RobbiZ4]

Originally Posted by rjahl

I don't feel that replacing a underrated or deficient design with another replica is a solution. Relays are not voodoo science. If we are assuming the points are overheating and melting closed, either the relay was defective or it's being asked to handle more load than it was designed for. Relays should work for thousands of cycles without any issue. I'd rather correct the reason for the failure.

I'm still not 100% convinced that an aging motor could not draw excess current and overload the relay. We are mainly looking at the starting current when the relay closes. That spike is usually too quick to blow a fuse but can be high enough to damage contractors.

Does anyone know the actual motor load and current rating on the relay?

Didn't find any specification of this unit till now.

Initiated by your thougths. I've separated the hydraulic unit from the motor. The motor is completely defective and doesn't move anymore due to the melted plastics. The hydraulic unit instead is in a perfect condition, no friction at all.

From my point of view the relays are not weak, it's the electrical setup of the CTM and the two relays:
no additional switch to shut down this unit if a relay fails, no temperature control after the opening/closing sequence has finished as the CTM shuts down immediately.

And at least, replacing the relays all 2 to 5 years is much cheaper than anything else. Handle it for eaxmple like the maintenance of the brake fluid.

[rjahl]

When I get my Z back from the Dealer, I'll try to use my DC clamp on the motor leads to measure the actual current draw.

Ya, car has been in the shop having the top realigned. Last service before my CPO expires. They also dropped the transmission to replace a gasket.

[Mayhem]

I just replaced my relay yesterday. From seeing the location of the relays in the trunk, I am wondering if the failures are coming from moisture getting into that area of the trunk. I noticed it was in a recessed area, and perhaps water and moisture seeping in is what has caused the relays to short?

[RobbiZ4]

Originally Posted by Mayhem

I just replaced my relay yesterday. From seeing the location of the relays in the trunk, I am wondering if the failures are coming from moisture getting into that area of the trunk. I noticed it was in a recessed area, and perhaps water and moisture seeping in is what has caused the relays to short?

Did you read the analaysis of the destroyed pump? Google translate will be your frind.

Go back to #2

The reason of the damaged pump was a melted kontakt of one of the two relays. No water or moisture.

[Mayhem]

Originally Posted by RobbiZ4

Did you read the analaysis of the destroyed pump? Google translate will be your frind.

Go back to #2

The reason of the damaged pump was a melted kontakt of one of the two relays. No water or moisture.

Yes, google translate is your friend. My question is, did the relays fail *because* they were shorted out by moisture? I get why the pump was damaged. I’m asking what caused the catastrophic failure of the relay itself? I’m not buying, “just because.” Before you get snarky with me, maybe you should take some time to read what I wrote.

[RobbiZ4]

Originally Posted by Mayhem

Yes, google translate is your friend. My question is, did the relays fail *because* they were shorted out by moisture? I get why the pump was damaged. I’m asking what caused the catastrophic failure of the relay itself? I’m not buying, “just because.” Before you get snarky with me, maybe you should take some time to read what I wrote.

No water in the trunc, no moisture at all.
Water can shorten a contact, but AFAIK never melt contacs. That means, if there is too much moisture in the trunk, the pump might start uncontrolled, but you can't find a melted contact in a relay.

[Romer]

I don't read him being snarky with you. Remember, English isn't his first language and I appreciate his reaching out outside of his home country to help other Z4 owners.

I am a moderator on a different forum and I find a lot of times it is the way the user reads the post which has a different tone than the way the author intended. Just trying to keep to keep the peace

[rjahl]

Originally Posted by Romer

I don't read him being snarky with you. Remember, English isn't his first language and I appreciate his reaching out outside of his home country to help other Z4 owners.

I am a moderator on a different forum and I find a lot of times it is the way the user reads the post which has a different tone than the way the author intended. Just trying to keep to keep the peace

Agreed,

My posts could have come across as being confrontational as well.

[cra3y]

Hi

Did You measure the actual current draw of hydraulic unit? I want to replace both relays in next week, but I'm kind interested of numbers (does current draw of hydraulic unit exceed this relay specs or not)

[rjahl]

Originally Posted by cra3y

Hi

Did You measure the actual current draw of hydraulic unit? I want to replace both relays in next week, but I'm kind interested of numbers (does current draw of hydraulic unit exceed this relay specs or not)

I've had a little problem.

Hit a piece of road debris and wound up in a ditch.

Road debris was a driveshaft from a simi and I was running 75 plus. SUV in front of me simply ran over it, so no brake light or swerving. Was an early morning run through Orlando and traffic was thick. Three other cars fell victim.

If I see my car again, it will not be for weeks. No damage to the external body but the undercarriage and steering were wiped out. Something jammed the steering completely. Wheels are intact and the alignment was not visibly knocked out. Too much grass and mud underneath to really see. I'll know more next week.

[RobbiZ4]

Originally Posted by cra3y

Hi
Did You measure the actual current draw of hydraulic unit? I want to replace both relays in next week, but I'm kind interested of numbers (does current draw of hydraulic unit exceed this relay specs or not)

Don't have a clue. Till now I didn't find any technical information about the pump and their power consumption. No equipment available to measure current draws of several 10 amperes.

The replaced original relays will fit for another 2 up to 5 years, that's the cheapest solution, I assume.

Update November 2019
In between we have measured a maximum of 37 amperes.

[cra3y]

Originally Posted by rjahl

I've had a little problem.

Hit a piece of road debris and wound up in a ditch.

Ah! Ouch! I feel very sorry ....

[rjahl]

Originally Posted by cra3y

Ah! Ouch! I feel very sorry ....

Ya, just glad no one was hurt. If I lose the car, it's just metal. Already think about a replacement, if I need to go that way.

Should see the rental Hertz gave me. Kia Soul, only car left on the lot. .

[Romer]

Replaced the relays. Really easy and $36 on Amazon. The module lifts a bit so easier to see to put the new ones in. Thanks Robbie for the info and great technical post

[Lurcher]

Originally Posted by rjahl

Ya, just glad no one was hurt. If I lose the car, it's just metal. Already think about a replacement, if I need to go that way.

Should see the rental Hertz gave me. Kia Soul, only car left on the lot. .

Damn - glad you are ok - these don't come with 4 wheel drive :-)

I'll be east of you in a little over a month if you end up in something else and want to see a red z......

[rjahl]

Originally Posted by Lurcher

Damn - glad you are ok - these don't come with 4 wheel drive :-)

I'll be east of you in a little over a month if you end up in something else and want to see a red z......

Approval came in today, car will be fixed. I was "lucky". No damage to any of the body panels, not even the front bumper. 10k in parts and 20 hours of dealer labor and it will back in my hands.

The road debris cleared my front bumper and made a direct strike on the steering rack. It's crushed and frozen solid. The rest of the damage is mostly heat shields and exhaust.

[rjahl]

To further Hi-jack this thread. I was able to inspect my car yesterday. The damage is incredibly light. No paint or body work required. No frame damage or anything close. If the steering box had survived the impact, I would have driven it home, no problem.

The electronic steering box is something to think about. Check out the "strike" and what it took to jam the internals. It's not just a loss of power assist, it's frozen. Insurance adjuster marked the damaged areas in yellow.

The steering box is up front and low in our cars and the damage sent me off the hi-way and into a ravine. I wonder if many other people have jammed their steering box in this way?

Now the good news, I'll get the car back in a few weeks. Dealer quoted less than 20 hours to fix but they needs parts from Germany.

[BuddhaPilot]

Originally Posted by rjahl

Approval came in today, car will be fixed. I was "lucky". No damage to any of the body panels, not even the front bumper. 10k in parts and 20 hours of dealer labor and it will back in my hands.

The road debris cleared my front bumper and made a direct strike on the steering rack. It's crushed and frozen solid. The rest of the damage is mostly heat shields and exhaust.

Wow, 10K in parts! Whenever you get a breakout of what all is being replaced would you please post? I'm a little concerned at the prospect of having to replace a steering rack or the possibility of my wife's Z4 being totaled if something similar happens. It's a 2009, so that much in damage would probably do it. All too likely with some of the crap we see all over I-26 in S.C.

[cra3y]

My old relays (I replaced today with new ones). One of them is more worn in contactor area. Date is 0911 (november 2009). I had over 2500 roof cycles operations

1) I think that this is one responsible for moving whole pack up (the pump has to work harder, so much more current flows thru this one)



2) This is less worn than the first one