Do I have bad coils?
12-04-2018, 06:44 PM
#1
Do I have bad coils?
I’m pretty new to the forum, and to the 964 world. I bought the car a little over a year ago, and so far it’s been pretty problem free. I recently had the car sit for 3-4 weeks, and went to drive it today and after a few minutes got an intermittent beeping sound couple with random lights coming and going on the dash. Possibly just a low voltage from sitting, or possibly need coils replaced aka Christmas tree effect. Here’s a link to a short video of the issue: https://imgur.com/a/63nRW9J
and a quick pic just to make an introduction
12-05-2018, 12:46 AM
#3
Instructor
One of my coils was corroded internally and had a similar effect. Easy tell a bad coil from visual inspection
Under the cap.
If your car is a C4 then also check the accumulator or listen for the pump running for a long time.
12-05-2018, 06:12 AM
#4
Rennlist Member
Your voltage at idle should be around 13-14 volts. You should also check battery, starter grounds. Many have reported that old or dying coils will cause the" Christmas Tree Effect".
Hard to really test coils, they can test positive, and still have internal faults.
Hard to really test coils, they can test positive, and still have internal faults.
12-05-2018, 08:58 AM
#6
IHI KING!
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How old are your spark plug wires, caps and rotors? The Christmas tree effect is caused by high voltage leaks at either the spark plug wires, coils or distributor caps.
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12-05-2018, 06:15 PM
#8
Just charged the battery overnight, idle voltage is at 13.5 today. Revs dropped every minute or so at idle, and still had the Christmas lights after driving a few minutes. I guess I’ll have to look into a 993 coil conversion, seems reasonably simple to do.
12-05-2018, 06:20 PM
#9
12-05-2018, 07:06 PM
#10
Race Car
When it's pitch black outside - start the car and spray a light mist of water around the plug wires...if you see blue sparks, you know you have leaks in the wires.
If by 11 years, you mean the caps and rotors as well, then those are due regardless. Don't buy beru caps and rotors. Beru wires are fine, but their caps and rotors are garbage. Bosch for caps and rotors only.
The 993 coil swap is simple. So if you are of mind to spend to do that, get that done. They are much more reliable.
If by 11 years, you mean the caps and rotors as well, then those are due regardless. Don't buy beru caps and rotors. Beru wires are fine, but their caps and rotors are garbage. Bosch for caps and rotors only.
The 993 coil swap is simple. So if you are of mind to spend to do that, get that done. They are much more reliable.