I got myself a 1993 C4 last month (73,000km). Very happy so far except on the first start of the day the (!) lights stays on with the differential warning light....there's a 'beep...beep' sound too! This lasts for about 20 seconds then all warning lights go out and the sound stops too. Surely this can't be normal.
I've been told it might be the brake system trying to get upto correct pressure, but taking too much time......is this correct? If so, what can I do to cure this problem?


Thanks in advance............Cheers!

 

I had the same problem too. Initially I was getitng the diff light but after a few days I started to get the ABS light as well. Got me pretty worried! It normally happened on the 1st start of each day. I also found that if I took the revs upto around 3000/min, the lights went out! It tured out to be the voltage regulator on the alternator. The alarm was going off because the ABS/Traction control were not getting up to pressure quick enough.

It is normal for the Traction Control & Brake pressure light to stay lit for a little while after startup though while the system pressurises.

Hope this solves your problem!

Andy
'90 C4

I am sure it won't be the control unit as if this fails the lights would be on all the time.

<img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />

 

This is quite normal. The beeping indicates that your hydraulic pump is working hard. The battery is posibly low on capacity. The hydraulic system takes up to 60 seconds to reach max pressure. The PDAS and Brake Warn lights will be on for 20 to 40 seconds depending upon the age of the C4.
You might also find your alternator output is low. However do not go looking for problems that are not there.
Ciao,
Adrian
911C4

 

I have not heard the beeping sound for a couple months and I'm wondering if it's attributable to the warmer weather. A couple months back, morning temperatures in Chicago hovered around freezing which I know impacts the battery charge, but would it also impact hydraulic pressure and other systems?

 

Yep, got exactly the same thing 2 weeks into new ownership - diff & brake warn lights and bleeper at cold start up.
Still happens sometimes, but bleeper cuts off after 3 beeps max. Pretty sure Revs have no effect for me.

Posted a question about it (quite recently), but didn't acheive the 'this is normal' response from Mr Streather I was hoping for. (got some other helpful stuff about repressurising, though)

So I stayed a bit worried - but now I'm happy again!

 

I would certainly not worry about this situation. Here in Switzerland it is very normal in winter when the battery has been used a lot. However when you get the oportunity have your alternator output checked and the battery capacity checked. There really is nothing to worry about but I do understand it might take some convincing,
Ciao,
Adrian
911C4

PS: I partly overcame this problem by the use of a solar battery charger. You have to understand that the 964 is a major electricity user and a low battery causes a few glitches and sounds until it gets back its strength.
PSS: it is Adrian by the way not Mr Streather. I am one of the most informal people you will ever meet.

 

Thanks Adrian, I'm convinced!.
Now I think about it, the 'problem' is prob. worse after a few days of non-use. No other signs of battery/charging illness so far though, thankfully - I'll get it checked out though.

P.S Just joking with the 'Mr.' thing. Actually referred to you as 'Uncle Adrian' in my recent '5 little questions' post, but I think I got away with it....

 

Dear Johnny,
If the C4 sits for a few days in the cooler climes then this is 100% normal behavior,
Ciao,
Adrian
911C4

PS: I did not notice the uncle thing myself but right now I prefer just being "Adrian". I think the reason is obvious.

 

Hey 1993HK964C4,

Are you from HK? I myself live in HK. Where did you buy your car from and where do you service your car? Jebsen?

 

Hi GT9111,

Yes, I'm in HK. Got my car from Promax (0 owner). The car was taken to Jebsen everytime by the previous owner so I'll probably do the same. Expensive I know, but do you know any other good professional Porsche specialists in HK?

Thanks!

 

Hi 1993964c4


Ah! Yes, from Michael Liu. In my opinion,the first maintenance after purchasing a car is to get a full service from the dealership, to thoroughly check the car's mechanical and electrical parts. But, since you mentioned that your car is serviced at Jebsen everytime by the previous owner, I wouldn't worry about the car's history.

Besides, going to Jebsen for service, I drive my car to Continental located in Kowloon Wan for modifications and services. The gararge specialises in 911, 993, 996 (street and track versions). I'll give you details if you're interested. Besides, if you know friends who drive a Porsche, chances are they'll know the garage as well.

 

Hi guys,

I ve got my 89 C4 now for 7 - 8 months and I ve never heard any kind of beep/boing/noise etc. at all .... anyway to test this beep ? What might be the trouble be ?

Thanks very much, nice ride

WSP964

 

Hi 1993964C4,


By the way, is Frankie from Jebsen the person who told you that the beeping sound is "the brake system trying to get upto correct pressure" ?

That's the same answer I got from him when I asked him about the sound.

 

Hi GT9111,

It was not Frankie who told me about the problem, but a man at 'Road & Track' (another Porsche garage at Lam Tin - they help me do jobs on my 968 coupe).

Please can you supply me with Continental's number? Thanks!

Bye.

 

If its not Frankie, then it should be Barry Forth at "Road & Track". Excellent garage but a bit expensive, to me anyway.

The phone no# for Continental is 2304-1415, look for Ah Fhat(if you know Chinese, Fhat is pronounced the same as the Chinese word for "wealthy).