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Loren

Spark Plug Change Instructions

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Spark Plug Change Instructions


Note: Part numbers sometimes change without notice. Always double check with your supplier that you have the latest part numbers. Parts you will need: 6 ea 999 170 207 91 Spark Plugs (Beru 14FGR 6KQU) MY99-MY01 or 6 ea 999 170 223 90 Spark Plugs (Beru FGR 5KQE0) MY02 Tools you will need: Jack 19 mm socket for wheel bolts Snap-On S9706 Spark Plug Socket Snap-On FXW4 (4 inch) Extension (or any 3/8" drive extension that allows at least 16 degrees of offcenter movement)

 

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Tools you will need:

Jack

19 mm socket for wheel bolts

Snap-On S9706 Spark Plug Socket

Snap-On FXW4 (4 inch) Extension

(or any 3/8" drive extension that allows at least 16 degrees of offcenter movement)

3/8" Ratchet

5 mm hex allen socket or 5 mm allen wrench

Torque wrench

I'd like to add that its best if you also have

- a 3/8" universal joint. (so you can bend for reachability - esp for the rear most spark plugs)

- a small 3/8" ratcher (the space for movement is tiny!)

- a 1/4" universal joint (for reaching to the hex nuts keeping the coil plugs fastened to the engine)

  1. Push on plug coils and tighten the fastening screws (M6 x 25) to 7.5 ft-lb. Reinstall the bottom screws first and then top. Subsequently push on the connecting cable of the plug coils.
    post-2-1132090790.gif

Loren, is it ok to hand tighten the plug coil fastening screws (M6x25) ? I can't seem to fit the torque wrench plus my torque wrench doesn't go down till 7.5 ft-lb. I've hand tightened it to "quite hard" (how's that for quantitative measures :) )

Also any tricks to work on the rear most spark plug on the left/driver side? That one seems to be a PAIN to reach ... my fingers are sore and I'm going to try that one tomorrow.

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Hand tight is likely ok. Just be careful that you don't over tighten them and crack the coils.

I agree the the two spark plugs furthest to the back of the car (on each side) are the hardest to get to (especially if you have big hands like me).

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This forum is great, but on this topic I'm sort of a Doubting Thomas.

I need to really ask after doing four (the front four) and need to do the back two.

Just to confirm, there's enough space to pull the coil out on the back two without removing anything else? How much contortion of the coil lead is acceptable?

Same question on the plug? On the 2nd one back I finally figured out the only way to get the socket + extenstion in/out of the tube is to do it in sections.

Lastly, what kind of torque wrench fits in that confinement?

Thanks,

Dale

<_<

2000 C2 Coupe, 6sp

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I just finished changing my plugs, man what a pain in the rear but there is no better feeling then finishing the job.

Here's a few pointers that helped me.

1. grease up the other end of the spark plug (only the part that makes contact with the socket), this way your spark plug socket does not get stuck onto the plug.

2. I used many small extensions to get to the plugs. I would get 1 part of the extension in the space first, and then I would get another extension into the small space and then connect it while i"m in the small space. For me, this was the easiest approach. There are alot of other ways to do it but this was the easiest for me.

Good luck!!!

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Does anyone have some live pictures of the procedure? I would like to see the bolts on the coils and the cover plate. Thanks

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I changed plugs and coils this past weekend on my 1999 C2 cab. Replacing the coils completely fixed my rough idle when cold. The car also runs much better. I found two coils had significant cracks and two more had hairline cracks just developing. Why coils aren't called out in the maintenance checklist from Porsche is beyond me. (As well as why they haven't found better material to make the coils out of!) The project took me the better part of an afternoon as I took my time doing this for the first time on a P-Car. I had one fussy wire harness connector that took a while to separate from the coil. I found the spark plugs themselves quite easy to remove/replace on all cylinders. For me, the hardest part was removing/replacing the cap screws on the rear coils. Just plain awkward, but obviously, doable.

For the previous poster, here are some pictures...

1. View of the shield on the right side of car looking from rear axle to the rear of the car. The two bolts to be removed are called out...

post-20664-1192625881_thumb.jpg

2. With the shield removed, this is a view of the coil on the forward cylinder. The two cap screws are clearly visible. To the top right of the coil is the wire harness boot...

post-20664-1192625886_thumb.jpg

3. This is a view looking across the head toward the rear of the car. You can see all three coils. Also visible are the two bosses that the shield bolts to...

post-20664-1192625892_thumb.jpg

4. This is a view of the forward cylinder with the coil removed. The wire harness connector is visible in the upper right. What's not obvious in this camera angle is how deeply the spark plug is recessed. It is about four inches to the bottom of that tube...

post-20664-1192625898_thumb.jpg

5. First cylinder done, new coil in place...

post-20664-1192625904_thumb.jpg

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A couple of more tips for the 996 spark plug change which I did last week on my 99 C4.

I only put the rear of the car on jack stands per the jacking instructions as I only needed the rear wheels off.

The coil wires come off by pushing the rubber boot towards the engine (as noted), but push at the top of the boot (not at the coil) where the wire enters the boot. You will see a raised retangular area on the boot as seen in the pictures. Push at the top area of that rectangle.

The 5 MM allen hex bolts for the coils are much easier to access if you have a small ratchet (Chapman, Sears, etc.. sell small hex bit ratchet wrenches). I had a 3/8 drive hex that was too big for the top bolts on the rear two plugs (closest to the rear bumper). Buy a hex bit set and a small ratcheting wrench that accepts 1/4" bits unless you already have a 1/4" drive ratchet, that may work. You can use an standard allen wrench to get the bolts out, but no ratcheting makes it time consuming.

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2 other comments I'd like to make:

1) Insure you completely reconnect the spark plug wire to the boot by tugging gently on it after you install or by insuring you hear it click in place. If it's not completely connected, you will have a misfire and the CEL will come on.

2) Also, in jstephanou's last pic: the cable in the foreground is the engine ground. If you loosen this to better access that plug, INSURE you tighten it completely. I didn't and spent the afternoon trying to figure out why my car wouldn't start...

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Anyone changed spark plugs on a C4S? I removed the 2 bolts for the shield. There isn't enough room to remove the plate! It looks like I may have to remove the muffler and the muffler bracket. Any comment?

thx

Mike

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Anyone try this on an '03 996 C2?

The first two plugs on the driver side weren't too difficult to reach, but the rear most plug, drivers side was very close quarters.

Same experience for the first two plugs on the passenger side; the first was very easy, the middle one a little 'awkward.' However, that rear most plug on the passenger side was a real challenge. I have small hands and still just could not reach into that plug; the exhaust pipes, cats, and heat shields blocked access and I'm just not flexible enough to reach from the wheel well.

I was set to surrender and take it into an indie shop, but instead elected to try and remove the exaust header; afterall, I had replaced the other five plugs. It came off quite easily with a pneumatic wrench. But still, that led to a whole different challenge, especially as I was replacing the header; of the six bolts, the rear most bolt stripped on the first two or three threads (this was after I had began each of the six bolts by hand to make sure the head and the gasket were sitting where they wanted to sit). So, I am off to the mechanic tomorrow to see what damage (and how much it will cost) to get a replacement bolt back in it's spot.

But...other than that....I was able to inspect all of the coils, wires, and replace the plugs. The whole experience took me around 5 hours (most of that on those two rear plugs).

Next on the list is the serpentine belt......

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I have a 2003 C4S. I just did the spark plugs at 45K.

The BERU original spark plugs were gone in my opinion. Porsche recommends change at 60K on the spark plugs but do yourself a service and change them early. The car is in warranty with Porsche but I didn't want to pay for the service plus it gets me to know my car.

When I went to the dealer he also suggested to change now the spark plugs; probably he knew that they are gone. Anyhow, I change them with NGK Iridium BKR6EIX; I got good experience with this brand on other cars.

After I change them I noticed an improvement in power and the sound of the engine changed for better.

The one in the middle and back, behind the diver were the most difficult. You have no choice but to bend the metal shield on this side to get it out. Also prepare yourself to remove the electrical connections on the back of the coils -HV transformers- (that are attached to the end of spark plugs); there is no way to remove them without this maneuver. I used a flat screw driver (to slowly raise the lock and push back) and some funky moves (look where the chop sticks came in handy!).

All 6 coils are cracked; I will go to the dealer and ask to change them for free. You let me know what are my chances.

The idle is a little unstable. It moves between 750-800 and I tend to blame on those cracked coils (the new spark plugs didn't change the behavior). If you have an idea where to look send me an email.

On the passenger side is simpler.

Took me 6 hours and I am a handy guy. I have a hand bruised but I am smiling :D .

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For those of you who have a hard time getting to cylinder 1 and 4 plugs!

I followed Loren's instructions and was able to change my plugs. However, getting to plugs of cylinders 1 and 4 was pain #@??)*... but I got it.

The second time I had to do this I removed the mufflers. This gave me a lot of room to work with and made the job a lot easier for me. Took me about 20 min to take both mufflers off the car. Just loosen the bracket on the cat side and the 3 13mm nuts holding the muffler to the engine support bracket (see pic).

You don't really have to do this, but if you have big hands and a only small collection of extensions and universals this will help you a lot.

Good luck.

post-1-1208396946.png

Edited by Loren
made image viewable

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HELP! HELP! HELP!

I'm in the middle of replacing my plugs and am currently working on the passenger side front plug (the hard to reach one). I removed the old plug with no problems but when I went to insert the new plug, I can make it in about four turns and then it stops. I'm afraid it may be Galling up in there.

What should I do? Should I try some never-seize or do I have a more serious problem on my hands.

Any help would be much appreciated. Thank you.

-Nichlolas

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Problem fixed! Sure enough, the plug had completely galled about 1/16" on the first thread. I am using the Beru plugs on my 01 boxster, as that is what Pelican parts claims is OEM. However, the old plugs I took out were indeed Bosch, so I guess Pelican is incorrect. The Beru plugs have stainless steel threads as opposed to the stronger and less-galling copper or brass threads of the Bosch plugs. The key here is, you need to use Never-Seize on the Beru plugs to make sure that you don't gall the internal threading in the engine, cause then you have a BIG BIG problem like I did today. Also, do not even think about using a wrench to tighten the plugs until the very last turn. The plug must go in by hand, but if for some reason it should not then you have to go to Plan B.

The parts guy at Pep Boys walked me through these steps and it ended up working for me. Plan B involves using a spark plug threaded Tap (available at Pep Boys) to clean up the inside threads. The problem with the tap you get at Pep Boys is the fact that the socket needed to drive it in is too large to fit into the first part of the spark plug hole. Instead what I did, is to use the larger-tap on the other side (the tap has two heads, one big and one Boxster-sized) to set itself snugly into one of my larger sized hex-sockets. I know this might destroy the socket, but it is totally worth it, and should now fit into the spark plug hole. Coat the useful side of the tap with some form of thick grease, that will be used to trap metal particles that you scrape off during the tapping process. Don't overdo it on the grease, but get enough in the intermittent grooves to trap the particles there. A lighter layer of the grease on the threads will help lubricate the tapping. Insert the tap into the hole and rotate it slowly counter-clockwise until you feel it set in the first thread, then advance it clockwise as usual. SLOWLY advance and then back out the tap. Do not use too much pressure, even though a small wrench may be needed to help advance the tap through the galled portions. You never have to apply hard pressure and there is never any seizing. If it is seizing you need to back out, clean your tap, regrease, and re-enter. Remove the tap completely very often in order to clean off the grease and metal shaving, then re-apply grease and begin again. By slowly inserting and removing the tap many times you should be able to clear most of the gall and get your plug through. After you have made good progress on the threads, do not try to force the final few threads of the tap through. I believe my tap was slightly longer by about 2-3 threads than what was needed, so don't make a new thread inside your engine! Good luck if this should ever happen to you.

-Nicholas

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The Snap-on spark plug socket listed, is that just a regular spark plug socket?

Yes, 5/8 inch deep socket with rubber insert to hold the plug.

The tool that is a little hard to find is the short wobble extension. Both Sears and Harbor Freight have them for reasonable prices.

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one quick question Loren

i went to my local Porsche dealer (porsche of downtown L.A). i have a 03 996 and they gave me spark plugs with the # 999 170 221 90. Are they the correct ones? Can i use these? i already took out the old ones and the tip is completely different. please let me know what i can do. thank you

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For a MY03 996 the correct plugs are FGR 5KQE0 - part number 999.170.223.90

Looks like they gave you Cayenne plugs.

thanks Loren , i appreciate all your help :D

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All, I'm getting ready to do my plugs on my 986 and found this thread. I thought I'd pass along a find on a great tool that I've used on my BMW which requires similar contortionist moves and deep sockets. After years of cussing out my crappy rubber plug sockets and ALWAYS losing them in the engine no matter what I used to secure them to extension and digging them out with screwdrivers, hooks, and all sorts of crap.

I finally broke down and bought this set from KD Tools. It's 3 x 3/8" drive, 5/8" spark plug sockets with swiveling (attached) extensions in 4", 6", and 11" lengths. And best of all, they're magnetic! No more rubber crap.

Best Info on them

Best Price - $34.99

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All, I'm getting ready to do my plugs on my 986 and found this thread. I thought I'd pass along a find on a great tool that I've used on my BMW which requires similar contortionist moves and deep sockets. After years of cussing out my crappy rubber plug sockets and ALWAYS losing them in the engine no matter what I used to secure them to extension and digging them out with screwdrivers, hooks, and all sorts of crap.

I finally broke down and bought this set from KD Tools. It's 3 x 3/8" drive, 5/8" spark plug sockets with swiveling (attached) extensions in 4", 6", and 11" lengths. And best of all, they're magnetic! No more rubber crap.

Best Info on them

Best Price - $34.99

On a Boxster the muffler is not in the way - so it is much easier.

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