993 rear spoiler problem

[saxony_wu]

Recently my 96 stock 993's rear spoiler is kind of on and off acting up. It is supposed to pop up at 50 miles. On normal speed acceleration it pops up OK most of the time; but if I step on it at quicker pace it stops to react. Feels like no signal is being transmitted to the spoiler motor.

The red light on dash will then come on til the car comes to complete stop. It is really annoying and distracting. I lubricated all the mechanical parts and linkage; checked all the connections and all seemed normal.

Has anyone experienced similar problem and any suggestion where I should look into next?

Thanks in advance....Steve

[david dolan]

Sounds familiar, in my case it was the bearing inside the gear housing that died. I followed this procedure to fix it, works great now!

993 - Rear spoiler Gearbox - pcarworkshop

[TMc993]

Thinking out loud.....Have you sttempted to raise and lower the spoiler using the switch in the cabin? If that function works properly, at least you would know that the mechanical aspects of the spoiler mechanisms are functioning properly....I think.

[david dolan]

Mine was like saxony describes in the beginning and then progressively became worse so that it wouldn't work at all.
In the early stages the manual switch would still power it up and down too.
When it stopped working alltogether that's when I took it apart and found that the bearing had simply stopped the entire mechanism through lack of lubrication.
Easy to check it the motor works by disconnecting the wire cable between it and the gearhousing and then having a helper activate the manual spoiler switch inside. If it rotates it points to the gearhousing binding I'd think. If it doesn't work it could be the motor itself, I also had one of those fail due to water getting inside and rusting up the motor.

[saxony_wu]

Thanks guys for your input.

The switch inside cabin is working fine. No abnormal noise when raising /lowering it.

I'll take a closer look at the bearing inside the gear housing this weekend. Hopefully I can address the problem.

[TMc993]

Originally Posted by saxony_wu

The switch inside cabin is working fine. No abnormal noise when raising /lowering it. I'll take a closer look at the bearing inside the gear housing this weekend.

I'm thinking that if the switch in the cabin activates the spoiler and the spoiler is "working fine," then the problem isn't in the bearing, as the bearing function is the same in both the switch-activated and speed-activated process.

One more question...Have you attempted to deploy the spoiler with the switch in the cabin after the problem occurs at speed?

If you run the car up to speed and the (!) comes on, then try to fully deploy the spoiler with the switch, does the spoiler completely deploy? If it deploys and the warning light disappears, then I'd be looking at electrical connections, etc. before I cut into the spoiler drive....But that's just me.

[saxony_wu]

Hi TMc993,

Yes I've tried the cabin switch many times when the problem occurs at speed. Spoiler would deploy every time and warning light disappeared.

That's the reason why I suspected it may be a sensor issue or electrical connections of some sort. Just don't know where to look.

I'll take a look at the bearing and gear housing this weekend anyways; just to make sure.

Steve

[bri450sl]

On my '95, there are 2 micro switches that are set on/off when opening and closeing. I would check both to see if they are functioning correctly. If you open the engine lid you'll find 2 screws that secure the black cover over the gear houseing. Remove the screws and the cover hinges towards the finder to remove. Then the 2 micro switches can be seen.

[saxony_wu]

Any idea what those micro switches do?

Mine can be operated manually with the cabin switch without any problem. It just act up when accelerate hard. Normal acceleration presents no problem most of the time.

I'll take a look at it also. Thanks for your input.

[bri450sl]

I have not looked at the positons of each switch when open. I believe one switch is open and the other is closed. I'm wondering if your spoiler may have some play in it and the switches are not making a good open/close contact. I'm thinking upon acceleration, the spoiler gets "weighted" towards the rear and one (or both) switches gets a false open or close? Open the engine lid, remove the cover for the spoiler drive and raise the spoiler. Then, grab the rear of the spoiler and gently try to move it. See if one of the switches trips.

[david dolan]

These pictures may help!





However, It's quite simple to isolate the problem component as I stated in an earlier post if it's either a problem with the spoiler motor or the spoiler gearhousing.

Good Luck!

[Traveller]

Originally Posted by saxony_wu

Any idea what those micro switches do?

They limit the full up and full down positions of the spoiler. In other words, they switch the spoiler motor off when the spoiler has reached its full travel at each position (extended or retracted).

Locate the micro switches to have a close look at them and while having a helper manually extend the spoiler using the cabin switch, observe what is going on. Maybe they need adjustment and/or replacement.

[saxony_wu]

Thanks guys. Much appreciated.

Steve

[david dolan]

Hello, just giving this a bump to hear what turned out to be causing your issue.

[saxony_wu]

Hi David,

No luck yet. Still a mystery. I checked the bearing and most other mechanical parts. They all seemed to be in good working order. Oh yes, also the micro switches.

Talked to a Porsche mechanic and he said it may be the spoiler motor. I'm skeptical about that as the motor seems to be fine with cabin switch.

Right now it is working most of the time but from time to time it still acts up. Also I realize it does act up more often after the car is fully warmed up; ie after driving for 15 mins or more. That's something I hadn't notice before.

I'm tempted to unplug the main spoiler switch again so the whole system won't be functional. Beisdes the down force part, wondering are there any other bad consequences by doing that...

[saxony_wu]

Today a Porsche mechanic told me to replace the spoiler relate(964 618 212 00) under the glove compartment. He checked all mechanical parts and they are in good order. According to him, mostly likely that is the cause of my problem but the damn part is so expensive!!

[TMc993]

Originally Posted by saxony_wu

....I'm tempted to unplug the main spoiler switch again so the whole system won't be functional. Beisdes the down force part, wondering are there any other bad consequences by doing that...

I've had mine unplugged for almost two years. I thought that it might make a difference in cooling during the heat of the summer, but that wasn't the case. There has been no appreciable difference in cooling between an active or inactive spoiler and we've had two record hot summers the past two years.

I think the downforce comes in around 80-85 MPH.

[saxony_wu]

Another thought is to install a fixed RS spoiler. That will eliminate all the problem in the long run. Cost of the spoiler is almost the same as the relay. Still trying to make a decision....

[cgfen]

Originally Posted by saxony_wu

Another thought is to install a fixed RS spoiler. That will eliminate all the problem in the long run. Cost of the spoiler is almost the same as the relay. Still trying to make a decision....

r u serious?
the little grey box costs as mush as a spoiler?????????
i think you should find a local 993 owner and swap boxes for an hour or so and see if the issue migrates.

where do you live?

Craig

[saxony_wu]

Yeap...from our host it costs $350 something plus tax & shipping. Porsche dealers in my area sell them for $415 plus tax!

Problem is it's still a guess work. Not 100% sure if a new one can cure the problem. Also this item is a no return part. Swap box testing is a great idea but too bad I don't know anyone in my area who has a 993 with stock spoiler.