Help!! - Flashing Oil Light and an Audible Alarm

vulcan300 · 06-28-2008, 06:30 PM

Hello all,

I have an 86 Carrera Targa and need some help diagnosing a problem that just cropped up this morning. I had the car out yesterday and all was well.

The car starts up fine and settles down to a proper idle, when I release the parking brake the parking brake light, brake pad warning light and oil light all flash twice and there is an audible alarm that beeps twice. This has never happened before today. The oil pressure was reading normal at start up and the oil gauge began to move up as usual within a few minutes. I hopped out and checked the oil level on the dip stick and that too was moving up as expected (I also made sure there wasn't a pool of oil under the car). I let the car idle for another five minutes, checked the oil level, and it was in the proper zone so I thought all was well and it was just another idiosyncrasy of a 20+ year old care. I then took the car out for a test drive and within a few minutes the audible alarm was beeping at me and the oil light was flashing on and off. When I rolled the car to a stop the alarm went off and the oil light stopped flashing. As soon as I started rolling again and brought up the revs the noise and blinking started up again.

Have any of you folks experienced something like this before? My owners manual is useless on the subject and I haven't dug into my shop manual yet, but it likely won't be of much help either.

Any help/advice will be much appreciated.

Best regards,

J

Por_sha911 · Por_sha911's Garage

Does this car have an aftermarket alarm system?

vulcan300 · 06-28-2008, 07:30 PM

No, just the standard factory Alarm system. The alarm system is not Armed.

Eagledriver · 06-28-2008, 07:58 PM

There is no oil alarm system on these cars. They do use these lights for brake warnings. Maybe the audio and flashing lights is a brake warning. Possibly a bad micro switch in the parking brake housing? The car thinks the parking brake is on?

-Andy

vulcan300 · 06-28-2008, 08:04 PM

The parking brake and brake pad lights only flash when I release the parking brake. It's the flashing Oil Pressure warning light and the audible alarm that have me concerned, although the alarm is only an irritant. Even though the gauge is showing sufficient pressure if the engine isn't being lubricated properly it's bad news. I'm wondering whether I should just have it put on flat bed and sent to the nearest Porsche dealer.. What a way to start the long weekend (In Canada) :-(

Is there any way to manually test Oil pressure to verify whether there is a low pressure situation?

javadog · 06-29-2008, 03:57 AM

Yes, you can manually test the oil pressure by hooking up an external gauge, but that doesn't sound like your problem. As stated previously, there is no audible alarm on these cars that is related to oil pressure. And there is no reason that the parking, brake pad warning and oil pressure warning lights would all flash together if the car had low oil pressure. My opinion is you have something else going wrong with your electrical system. What audible alarm are you talking about? The seat belt warning buzzer?

JR

vulcan300 · 06-29-2008, 07:24 AM

Hi Javadog. The audible warning is a distinct double-beep that repeats every 2-3 seconds. It's different from the seatbelt buzzer and the car alarm. I'm going to try disconnecting and reconnecting the battery in hopes that resets things. If not I will record the sound and post it.

In your experience, does the low oil pressure light flash or should it be constantly read if it goes off?

vulcan300 · 06-29-2008, 08:12 AM

Well, I tried disconnecting the battery but no luck. The lights and noise at start-up still happen. However, when the drivers side door is open I can release the parking brake without producing the flashing lights and sound. When I close the drivers side door the lights and sound happen immediately after.

When I start the car the Pressure gauge reads three and idle is just above 1000. If I increase revs to 2000 the pressure reads 4, and at 3000 the pressure is just below 5. After 5 minutes of idling idle pressure drops to 2.5 and stays there. The oil level on the dip stick is halfway between the marks at 5 minutes. When I last checked it after a good run the oil was just below full and I haven't lost any oil that I can see since then. The oil level gauge starts at zero and is already into the white after 5 minutes which is expected.

The sound beeping sound seems to come from the Oil Pressure gauge or perhaps somewhere behind it in the dash. The stereo isn't turned on so the sound is not coming from the speakers.

Should I pull the gauge and inspect for broken/loose connections? I've never done any electrical work in the dash so I'm not quite sure what to look for.

janz · 06-29-2008, 08:50 AM

Just a shot in the dark here. If you have an aftermarket stereo, I have a sony, and whoever installed it made a mess of things that took me days to figure out and correct. The stereo may have some sort of alarm (the sony does that came with the car when I bought it) It has an irritating 2 or 3 beep sound that comes from the speakers wether its on or off (stereo unit itself) when I turn the car ignition off. Whoever the PO had install the radio managed to connect it to the lighting circuit so you can imagine what kind of havoc this played. Try to disconnect the stereo switched and unswitched power leads and see what happens. Never know as I chased all kinds of problems associated with the evil troll that installed the radio in my car. Picking the wrong hot wire to attach things to can lead to all kinds of back feeding problems that will make you stupid trying to fix them. Maybe your radio is going bad and thats why this showed up all of a sudden.
JANZ
86 Carrera

vulcan300 · 06-29-2008, 09:15 AM

Thanks for the advice Janz. I'll give it a shot tonight. I'll try just about anything right now. I'm guessing I just need to pull the deck and remove the haresses? Or is there more to it?

javadog · 06-29-2008, 09:22 AM

Quote:

Originally Posted by targamaniac

Hi Javadog. The audible warning is a distinct double-beep that repeats every 2-3 seconds. It's different from the seatbelt buzzer and the car alarm. I'm going to try disconnecting and reconnecting the battery in hopes that resets things. If not I will record the sound and post it.

In your experience, does the low oil pressure light flash or should it be constantly read if it goes off?

The oile pressure light will light when the oil pressure is below a certain value and will remain lit until the pressure rises above that value. It doesn't blink, unless the oil pressure is fluctuating from below to above this nominal value. From the description of your pressure, you have normal oil pressure.

There is nothing that Porsche put in the car that will make the sound that you describe. It's something that has been added to the car and the two most common suspects are aftermarket stereo and alarm systems. I'd kill both systems by removing the fuses in their power leads and see what you get. Make sure you have any anti-theft codes (if either of them uses one) before you kill the power. You should not have to remove anything from the car to accomplish this.

JR

vulcan300 · 06-29-2008, 06:25 PM

Hi Javadog,

Do I need to pull the deck out to get at power leads, or can I remove the fuse in the fusebox in the front trunk?

javadog · 06-30-2008, 05:27 AM

You don't need to remove the deck to disconnect it. If it's a stock radio, you can forget testing it, as I am positive the stock radio won't make this sound. If it is an aftermarket radio, there will generally be in-line fuses in both of the power leads. Look under the dash; any fuse holder you see will be tied to an aftermarket installation. There's no telling where an aftermarket radio was wired into the car's wiring to pick up the constant and switched 12 volt circuits without actually tracing the wires, so pulling the correct fuse in the front trunk would be impossible.

JR

vulcan300 · 06-30-2008, 06:33 AM

Thanks Javadog. It is definitely an aftermarket stereo so I'll give it a go tonight. I was trying to pull the deck itself with some coathangers but it wasn't coming out easily and I didn't want to force it. I'll go at it from under the dash and hopefully that does the trick.

In the extremely poor installation instruction in the stereo's manual it shows wires heading off to connect to other components in the dash so I'm crossing my fingers that this is the issue. The great mystery to me is why this came out of the blue when everything worked fine. It must be the exceptionally awful roads roads in my city that rattled something loose.

I'll report back with success or failure soon.

vulcan300 · 08-06-2008, 07:31 PM

Well after a good long time and much towing of my car on a flatbed my problems still aren't completely resolved. It turns out that the triple beep and flashing lights at start-up isn't unique to my car. A large number of the older cars that my mechanic works on (mid 80's to early 90s) do the same thing. What wasn't Normal is the flashing pressure warning light and beeping.

Taking the lead off the pressure sensor, cleaning it up and using some contact cleaner seemed to resolve the issue. A flashing pressure light and audible alarm apparently is a part of the pressure monitoring system in my car. I confirmed that the stereo has nothing to do with it.

But after getting this issue licked my engine stopped working after driving it back home with a failed cylinder head temperature sensor so it's back to work for me.. Not the greatest start to my Porsche experience but I guess it's the way it can go with a 22+ year old car.

Javadog, Janz and Eagledriver, thanks to all of you for your advice!

GH85Carrera · GH85Carrera's Garage

Quote:

Originally Posted by targamaniac

Well after a good long time and much towing of my car on a flatbed my problems still aren't completely resolved. It turns out that the triple beep and flashing lights at start-up isn't unique to my car. A large number of the older cars that my mechanic works on (mid 80's to early 90s) do the same thing. What wasn't Normal is the flashing pressure warning light and beeping.

Taking the lead off the pressure sensor, cleaning it up and using some contact cleaner seemed to resolve the issue. A flashing pressure light and audible alarm apparently is a part of the pressure monitoring system in my car. I confirmed that the stereo has nothing to do with it.

But after getting this issue licked my engine stopped working after driving it back home with a failed cylinder head temperature sensor so it's back to work for me.. Not the greatest start to my Porsche experience but I guess it's the way it can go with a 22+ year old car.

Javadog, Janz and Eagledriver, thanks to all of you for your advice!

That is something I find hard to believe. I have only worked on my cars so I am no professional. I have never heard of a double beep coming from a 911. I would love to see that in the factory wiring diagram somewhere. Can anyone confirm that a 911 was wired this way from the factory? It just sounds like a aftermarket alarm or radio thing.

vulcan300 · 08-07-2008, 05:44 AM

I personally saw two cars start up with the same flashing lights and beeps on release of the parking brake at my Mechanic's (and early 90s 911 targa and a mid-late 90s 911 Turbo). I disconnected the stereo and the beeps/lights at startup are still there and the beeping/flashing oil light while driving were still present. I also gave the car a thorough inspection for an aftermarket alarm and found nothing. Just the standard factory Alarm is installaed and it is not armed. It was only after I cleaned up the lead to the pressure sensor that I was able to make the flashing oil light/double beep condition go away. If there's someone on the forum that can comment on whether this is expected behaviour according to Porsche Engineering I'd love to hear it.

J

Zeke · 08-07-2008, 06:08 AM

Did anyone suggest to check the brake pads and sensors?

vulcan300 · 08-07-2008, 06:17 AM

Hi Milt,

No one has made that suggestion yet, but I just put new brake pads in the car at the beginning of the year and have probably driven 1000 miles since then. Next time I haev the car on the hoist I'll double check to make sure that the Brake Pad sensors haven't come loos from the pads. Or I may just cut them and short them so that they never bother me again :-)

J

Tim Polzin · 07:30 AM

Quote:

Originally Posted by targamaniac

If there's someone on the forum that can comment on whether this is expected behaviour according to Porsche Engineering I'd love to hear it.

J

I don't know that I'm qualified to comment on Porsche engineering, but I have an 86 and a long time ago, replaced the main wiring harness. As I recall, there was nothing in the electrics that was capable of beeping, the only underdash noisemaker (designed as a noisemaker anyway) was the door open buzzer.

The 964 and 993 that you mention at the mechanics are a whole different kettle of fish electronically and I know nothing about them.

A beeping noise on an 86 is resulting from something definitely not designed by Porsche.

Tim