Hello everyone,

Bought my first Porsche after my first time behind the wheel of any Porsche, 96 993 C4S (95K miles), in May and drove it back from Seattle to Houston. Awesome drive back! Even got my first ticket in Wyoming doing 92 in a 75 zone in the mountains. Trooper told me that a few more miles over the speed limit and he would have had no choice but to haul me to jail and the judge does sentence on a average of 2 to 4 days. Don't know if he was trying to scare me or what but I was not going to test him on it while driving through the rest of Wyoming.

Anyways, on the drive back the CEL was flickering on and off. OBDII code reader was reporting misfiring on cylinders 4,5, and 6. Finally got the garage and scissor lift ready to do some maintenace on the car. Decided to start on the distributor cap/roters and spark plugs since previous owner records shows that they have not been replaced since 50K miles. Bought some Beru's caps and rotors and Denso Iridium plugs. Found out on this forum that the Denso might have been a bad decision so just order some Bosch FR 5 DTC.

Printed out all of the excellent instructions on Robin Sun's p-car.com site and started on the job. Also ordered the RSR mufflers in June and finally got around to install them also. Found out that the spark plug wires are half chaffed off on the exhaust port 6 plug. Ordered a set of STI wires on eBay and replaced them also.

Now the problems begins:
Seized plug on the intake #2 plug. Only got it to move a quarter of an inch or so and have been moving it back and forth in that range and spraying liquid wrench in it for 4 days. Replaced caps/rotors, wires, and 11 out of the 12 plugs. Decided to put everything back together and try to loosen it up with the engine warmed up. Still did not loosen it up and now the car seems to be choking around 3K rpm in second gear on up. It is also making a clicking/clanging noise at that rpm range. Very unresponsive and reporting misfires on 1,2,3, and 4th cylinder now. The engine rev normal in neutral and 1 gear only with the faint clicking noise only at around 5K rpm.

I think I plugged all of the wires back correctly with the top cap for the exhaust plugs and the bottom cap for the intake plugs following the cap wire layout. Bosch plugs should be here in a couple of days and maybe replace those and see what happens because I am stuck, in more ways than one. But hey, at least it sounds cool with the RSR mufflers. Any suggestion would be greatly appreciated.

Tuyen Chu
96 993 C4S, 100K miles, HR springs, front Euro bumper

 

Wish I could help you out.... but I stop at swapping out steering wheels, bumpers or radios. This is way over my head. But yet I felt the need to respond to your post. Good luck and post some pictures. Welcome!

 

As much of a pain that it is, you're going to have to start from scratch and re trace all of your plug wires one at a time. You can't "think you put them back on right" you have to be 100% kinda like either a girl is pregnant or she's not. definately sounds like crossed wires. Keep working on the #2 plug, if it's loose is should come out with a little elbow grease. (hopefully the threads are'nt pooched).
make sure the wire caps are securely pushed on tight inc the coils.
check the dist belt too make sure both rotors are turning..
David

 

Exactly.

As for the clanging noise, that's probably due to the fact that you're running the engine with a loose spark plug. This is not good, and you should never do it again. Get the plug out and install a new one before starting the motor again.

 

I stop at detailing the car. I really wish I had your mechnical skills. Keep up with the posts and I'm sure you will find all the help needed. Congratulations on the purchase.

 

Be careful with the spark plug! The last thing you want to do is roll the thread and cause it to gall in the head. This could force you into a top end rebuild earlier than you want to. Aluminum heads are a PITA when dealing with this issue. The DENSO Iridian plugs do not work well in a 3.6 Porsche. I pulled them back out after 2 days of use and craped canned them and replace with a fresh set of "OEM" BOSCH FR5 DTC's. Keep using the Liquid Wrench or try some Sea Foam. Good Luck!

 

My tech told a friend with the same problem that he could freeze the plug which would probably allow it to turn out without damaging threads.

 

Thanks for all of the replies! I will double check everything and ohm out the wires to make sure that they are labeled correctly. OEM plugs should be arriving tomorrow and switch those out also. Denso plugs are going on the GF 02 Camry since they use the same plugs according to the Denso website.

 

Wurth offer an aerosol named 'Rost Off Ice' that I've had some success with with: it severely chills the object it is sprayed while depositing some penetrant ..... so may work on " freezing" the relatively small mass of the plug in an Al head.
For a pure penetrant, Aero Kroil is a brand that rarely fails.
If the plug were somewhat loose eons before you tackled it, it may be carbon fouled in place vs. normal metal oxide corrosion: in that case, any of the decarbonizing solutions used for valves/heads may be worth a soak .... GM 'kleens' is one available here - don't know if available in the US.

Re missfires, follow up on the dist. drive belt as mentioned .... and good luck!

 

Wait till you get the proper plugs, then go over everything again.

What are STI wires? I take it you didn't purchase wire for a Subie STI?

 

Progress!

Took both distributor caps off last night and the bottom one was literally "toast." Would post some pics but have not received membership number yet. The bottom rotor inside plastic notch was in pieces. I thought everything was idiot proof with all of the pieces having notches in them but I guess that was not enough. Probably did not push the rotor all the in before installing the cap because the top of the rotor was burnt also. Will replace both tonight and cross my fingers that was it and did not cause any further damage.

Seized plug rotated a couple of rev before it got tight again. More liquid wrench into it and see. I will try to get the other products mentioned on hand just in case I want to try those.

STI, Spark Transfer International, plugs.
http://www.karlynsti.com/Folders/Kar..._Wire_Sets.htm

BTW, nice tail on "Scarlet." Is that a turbo s tail?

 

Nice that you found it before it created any real damage.

On the plug, try going both ways, in & out, it will let the penetrant get into all the threads.

Do you have the wires yet? Do you like them? What did they cost? I'm looking at getting the wires replaced in a another 10kmi.

It's the Aero kit II, basically, it's a Turbo S body kit, minus the fender ducts.

 

The STI wires seems to be of good quality as others have noted also in the DIY.

http://p-car.com/diy/sparkplugwire/

It has "Beru" stamped on the wires themselves. I paid $410 for mine on ebay.

http://cgi.ebay.com/ebaymotors/PORSC...1121QQtcZphoto

If you don't have one already, the ratcheting screwdriver I think is a must have for this DIY. I bought the Sears one for $6 bucks instead of $24 for the snapon.

 

You can get wires from Corvettedude (email address escapes me) for a lot less. Around 140 if memory serves. You need to swap the caps, but so what. Worked for me.
I can also tell you from experience that although you may think you have all the caps seated properly, they can and will loosen up. After you swap the plugs for the Bosch, make sure they are all in all the way. + 1 on going in and out to work the lubricant and last but not least, you can also use an can of compressed air (from office depot) turned upside down, to freeze the spark plug.
BOL.

 

Got the seized plug out but have a little bit of thread damage because I cannot hand thread the new plug more than 1/5th of the way in.

Does anyone know what is the thread size of the spark plug on the top of their head? That would save me a little bit of time today getting the right size spark plug tap.