Wachuko

Changing Spark Plug Cables

UPDATE: June 16, 2009 - after keeping an eye on the threads that come up for the Xmas lights issue... I can say that the majority of the cases were due to bad coils. So keep that in mind before replacing the wires.

To eradicate the Xmas effect in my car. After replacing the starter and the positive cable connector at the starter bolt, I decided to replace the plug cables. Old ones were showing sings of wear and sparks were all around (you could see the sparks at night and all lights off… what a light show that was). Afraid this would cause more serious problems with the DME I order a set of cables. Buying this directly from Porsche was prohibited (in the upper US$800.00 for the set) so I got them from another vendor.

Distributor caps (2), rotors (2), oil filter, fuel filter, air filter, 12 Spark plugs – US$500.00. I also ordered a spare DME relay to keep it in the glove box and decided to order to new coils. Since the headliner in my top is torn I also sent for one (I already have new elastic straps to replace the old ones) - Total of the order with shipping - US$790.61

Parts came in today so I started taking out the stuff that is in the way to gain access to the cables…first time I do this in this car. Those that want to do it – seems complicated at first, but it is really easy… it just takes a lot of time since the cables are held in place in many points and reaching the bolts that hold them in place is kind of difficult…

I started by removing the covers on the sides of the engine (since I do not have the tray installed reaching these covers is fast and easy).

Then I removed the two bolts holding the cables that go over the fan housing. Inside this plastic curved cover you will find three smaller covers holding cable 4,5,6 in place. They snap off easy releasing all three cables.

I removed the a/c compressor to gain better access (the cables run under the A/C bracket so getting to them with the compressor in place is a pita) and also removed the airflow meter with the air filter housing. This will make it a lot better to get to the upper row of plug cables and the bolts holding them in place.

I will try to post photos along the way...

Wachuko

A few photos:

A/C Compressor out of the way... also notice the curved plastic over the fan housing already removed... along with cables 4,5,6





Another shot:

Wachuko

ahhh crap! they sent me the wrong cables... I got cables for a 993 instead of the cables for a 964

Project halted for tonight.

Different rubber grommets:



Different coil cable lenghts:





and different plug cables lenght:




time for a drink and to surf the net

Wachuko

A good thing that came from all this is that I found the source of an oil leak... I thought it was motor oil but turned out to be from steering fluid from the low-pressure hose that goes from the power steering pump to the reservoir.

garrett376

Thanks for the pics, it's nice to see what it all looks like with the junk out of the way! Keep sending them along!

And did you finally fix that starter problem???

Wachuko

I changed the starter but that was not the problem... although the old one was almost ready to be retired... The culprit was the positive cable. The terminal that goes in the starter was hanging by a couple of threads. It had some good electrical tape near the end that held it in place and made it look like it was ok. I ended up buying a piece of #1 cable and with a industrial crimping tool extended the original cable enough to put a new terminal and all was good. With that out of the way I started to tackle the second problem that appear that same rainy friggin night... the warning lights all coming on at once and the dreaded buzz...

The first time that happened was when I initially bought the car. At that time it was a weak battery and a trip to Sears resolved it. Thinking it was the same problem I went and bought one of those optima red top battery. After fixing the starter (well... you know) and the clutch slave cylinder (since I had a weird noise when releasing the clutch and the whole clutch has less than 15,000miles, I found here that sometimes the slave is the culprit... sure enough) I took the car for a drive that night and the warning lights came back on... quick search here led me to the ignition/spark plug cables. Did the test at night to double check...sprayed some water mist over the cables and distributor caps and the light show was impressive...

and here we are...

With all this stuff out of the way I am taking the time to check for any oil leaks... when I had the dealer repair the broken head stud, they replaced all seals in the car. I need to check the invoice but I am almost positive that I also asked them to change the oil pressure sender unit. With the steering fluid leak I am not sure if the oil I found was all from there or what... I will have to continue looking once I replace the leaking hose.

garrett376

You're supposed to spray water on the wires to see the sparks??? On my 65 I saw the sparks when dry; is it better to spray water on there? I have not heard of that trick before; I guess that would encourage the sparks a little, right?

jimq

I have the exact same leaking PS hose. Ordered it last week and going to change it today along with squealing fan belts and front brake pads. I had also ordered the other hose from the PS res. but it looks like a real bear to change out the back part of it. Anybody know if you need to get to the other end from under the car? Looks like 2 less 954's out mixing with all the I-4 Daytona race traffic today!

Wachuko

All right!!! Wife called me saying that the cables arrived... trying to get out of work early to finish this. Will be taking a few more photos and posting them here. Let me know if there is a specific area/photo anyone here needs.

Eric Kessel

Jaime,
Could you please photograph (before or after, doesn't matter to me) where the wires are clipped to the valve cover on the bottom, passenger side? My car has broken clips on the valve cover, and it's not clear how the wires are routed.
Thanks.
-Eric
90 C2
NER/PCA

Wachuko

Eric, will have to be after... that was the first side I removed.

Wachuko

That second one really looks like a major task to replace... mine looks fine(knock on wood). Also the one in my photo (the one that was leaking) I only had to replace the hose clamps, hose was fine.

Wachuko

Here you go:



and one more:

Wachuko

A few photos:





OK, right side is done.

Here is a photo of the new right side cables (the right one this time). They come with the plastic cover that goes over the fan housing, numbered, Beru...



I also took the opportunity to change the spark plugs (last time I could not find the Beru or Bosch and used some Champions... good thing it was only for 400 miles... could not sleep at night thinking the tip of the Champions would break. Got an additional 12 to keep them for the next 15k service).

and also changed the fuel filter... easy task with all that stuff out of the way.



That is all for now... will tackel the left side tomorrow.

Eric Kessel

Jaime,
Thank you very much. That does make things clearer. I was a little concerned about the first plug on the left with the bend where the plug connector boot meets up with the outer sheath, but if that's how it goes, i'm not going to worry about it.
-Eric
90 C2
NER/PCA