Tried to change the spark plugs this weekend

[b-man]

I tried to change my spark plugs this weekend. But, I could only change 4 out the the 6. I could not get to the rear plug on each side. I thought I heard it was possible to get to all 6 without taking apart the exhaust system but, that doesn't seem possible. I didn't want to take apart the exhaust system because I'd have another set of issues to deal with (some of the bolts are rusted and may break, I'd have to get everything lined up again, I may have to replace gaskets, I may have exhaust, leaks, etc.).

I was pretty confident before I started because I am a pretty experienced DIYer and have a pretty good collection of tools (including many extensions and joints). But I have no idea how to get to those two rear plugs without taking apart something else like the headers, mufflers, brackets or ???

For those who have not tried changing their plugs, I recommend taking it to the dealer. It looks like that's what I'll have to do for the last two plugs unless someone can give me some magic tip to help. :rolleyes:

b-man

2002 C2 Coupe

Edited May 24, 2004 by b-man

[Loren]

This is Jeff's pic. To get the back plugs you need the short swivel head socket wrench shown just to the left of the jack. Note: Do NOT use anti-seize on the threads.

[Tool Pants]

Chad and Loren changed all 6 on Chad's 996. The rears are a pain due to lack of clearance but it can be done. Very easy on a Boxster.

But Chad did have a helper.

[b-man]

This is Jeff's pic. To get the back plugs you need the short swivel head socket wrench shown just to the left of the jack.

So with this wrench, I won't need to remove any of the exhaust system?

Also, when I removed the heat sheilds, I couldn't remove them completely. I just took them off and let them lay down (I think they would lay on the header pipes). Is this normal or can you remove the sheilds completely? I felt that if I could completely remove the sheilds, it would have helped.

I need to get one of those helpers in my tool box.

b-man

Edited May 24, 2004 by b-man

[Loren]

So with this wrench, I won't need to remove any of the exhaust system?

Correct. I've never had to take anything else off.

Also, When I removed the heat sheilds, I couldn't remove them completely. I just took them off and let them lay down (I think it was on the header pipes). Is this normal or can you remove them completely? I felt that if I could completely remove the sheilds, it would have helped.

Hmm... only two bolts then they slide out the side. I usually take them all the way out since you need to get your arm back in there to the back plugs.

[b-man]

Also, When I removed the heat sheilds, I couldn't remove them completely. I just took them off and let them lay down (I think it was on the header pipes). Is this normal or can you remove them completely? I felt that if I could completely remove the sheilds, it would have helped.

Hmm... only two bolts then they slide out the side. I usually take them all the way out since you need to get your arm back in there to the back plugs.

Loren, was it on a 2002 model year Carrera? Maybe mine is a little different than the ones you've worked on? I took off the two bolts but definitely could not get the heat shield out of the way. Do you remember which end you took it out from?

I started to bend it to help me get it out, but then had second thoughts and just admitted defeat.

b-man

2002 C2 Coupe

Edited May 24, 2004 by b-man

[b-man]

Loren, was it on a 2002 model year Carrera?

I'll answer my own question. I don't think it could have been because I have what I believe to be the highest mileage 2002 911 in the world. It's got 65k miles on it and I don't think anyone is even close. Since these are scheduled for plugs at 60k miles, I don't think anyone has changed plugs in the 2002-2004 generation cars until now . . .

[Tool Pants]

Chad has a 1999 3.4.

[ant]

I have say its not the as easy as it looks on Loren's DIY write up, But its possible. I used the recomended tools and didn't even remove the rear wheels. Took about two hours. Thanks again, Loren!

[b-man]

An update (hopefully this information will be useful to someone):

I took it to the dealer and they changed the last two plugs. The mechanic said that it's much harder to change the plugs on the 2002 911's than on the 1999-2001's. He says it has to do with the new cylinder head/valve cover design. He also said the heat shield is completely different. I assume the 2002-2004 911's are all the same.

He was able to change the last two plugs without removing any of the exhaust system parts. He only had to remove the heat shields which come out when moving them towards the front of the car. Removal of the hex bolts was not too difficult but, he said removal of the coil pack was very difficult. He said he had to use needle nose pliers to get them off. He also said something about the angle of the coil packs being different on my car than on the 99-01's which make mine more difficult. According to him, the coil packs are the same for 99-01's and my 02 but, the way they are installed at the factory in my car made it more difficult to remove? I'm not completely sure what he was talking about but, I think that's what he was saying. I think it just has something to do with rotating the coil pack to be able to grab it or completely remove it? He also said that the passenger side rear most plug was the hardest one.

My fatal flaw was not being able to figure out how to completely remove the heat shields. If I could have done that, I'm confident I could have changed all 6 of the plugs. :)

FYI, my spark plugs (the 4 that I changed) looked pretty bad in my opinion. The mechanic at the dealer said the same thing about the 2 that he took out. There were 65k miles on them. The service manager said that they've been seeing that (crappy plugs when going to the new 60k mile interval versus the older 30k mile interval) as a trend in 996's. No, I don't think they were saying that to make money.

This is the first time in my life that I ever had to take something I couldn't finish or screwed up to the dealer. So, I'm looking forward to tackling this job again to prove myself.

b-man

[natzee]

I notice Loren's note indicates "Do not use anti sieze on the thread". Is there reason why we don't want to do that? I changed my spark plug a month ago and I actually did use the anti-sieze :-(.

Any feed back will be helpful.

-Nat

[Tool Pants]

The use of anti-seize is always debated, like what oil to use.

But if you ever had a steel plug get stuck in an aluminum head and the plug comes out with the aluminum threads.... Then you have to pull the head and take it to a machine shop for an insert. So I have always used it on plugs and did so when I changed my Boxster plugs 20k ago. When I change the plugs on other Boxsters I do not use it. I also use it on my motorcycles.

The threads are nickle plated which is said to prevent them from getting stuck. A long time ago I went on the Bosch or Beru site and it said there that anti-seize was not necessary.

I forget if the shop manual mentions anti-seize on the plugs. I asked Peter several years ago and he said Porsche said not to use it, and showed me a TSB issued in 1991. What does a 1991 TSB have to do with a 986/996? Well, until or unlesss Porsche issues a newer TSB you follow the old one.

If you search on the pelican site you will see a lot of theories on why not to use it, and just as many people who use it anyway. The plug can back out because it is lubricated. The plug does not make good electrical contact due to the anti-seize. If you smear it on the electrodes the plug does not work. It prevents heat from going from the plug to the head. You can overtighten the plug due to the lube.

I have changed a lot of plugs in 20 plus years and never had a problem with anti-seize.

[TSC85]

I have a 2002 C2 and yes the heat shield does come off, although I was scatching my head at first as well. I had to get a screwdriver and pry maybe 1/8 inch just to clear the mount, and it slid right out. I actually just tried my first spark plug change today and I will say that they ones closest to the rear bumper are a pain the A!!!!! I stopped for the night, but I will finish it up tomorrow. Oh by the way I did use NGK, and when I finish she's getting some fresh Castrol 5w40 Syntec.

[Loren]

I have a 2002 C2 and yes the heat shield does come off, although I was scatching my head at first as well. I had to get a screwdriver and pry maybe 1/8 inch just to clear the mount, and it slid right out. I actually just tried my first spark plug change today and I will say that they ones closest to the rear bumper are a pain the A!!!!! I stopped for the night, but I will finish it up tomorrow. Oh by the way I did use NGK, and when I finish she's getting some fresh Castrol 5w40 Syntec.

If you read the DIY Tutorial on this you will see that we think it is a lot easier to just drop the mufflers out of the way - adds 15 minutes to save 45 minutes.

[lex_gs]

I agree with Loren, drop the mufflers. In fact I went a step further and removed the bumper cover and heat shields first. Then removing the mufflers is easy and with the mufflers out of the way the plugs are easy. No need to bust knuckles and raise your blood pressure to stroke level. The whole procedure is in the DIY section called "Muffler bypass pipes". My 03 C4 with the the X51 engine looks to be impossible to change plugs without dropping the mufflers. I think the X51 headers are not the same as a standard engine. If anyone has done a plug change on an X51 I'd like to hear how they did it.

[goldenwarrior1]

Loren, was it on a 2002 model year Carrera?

I'll answer my own question. I don't think it could have been because I have what I believe to be the highest mileage 2002 911 in the world. It's got 65k miles on it and I don't think anyone is even close. Since these are scheduled for plugs at 60k miles, I don't think anyone has changed plugs in the 2002-2004 generation cars until now . . .

I have a 2002 C4S approaching 96K. I have changed the plugs twice and although the last 2 plugs are challenging they are accessible without dropping the exhaust but on the second change I dropped the exhaust because I needed to change the catalytic converter. Next time I will drop the whole exhaust as the little bit of extra work is well worth the effort.

[jasper]

I did all six plugs in my 2002 without dropping the mufflers. It took a full four hours. It was a tedious job, but not hard per se. I had the right combination of ratcheting wrenches and hex bits to get the job done and I'll admit that without the right tools the job would go from tedious to impossible in a big hurry.

Since I did this job I have dropped my mufflers a number of times for another project I had going...still not 100% convinced it would save all that much more time. I don't have to worry for another several years now though and who knows what the exhaust bolts will look like then.

Edited December 6, 2010 by jasper