replace your spark plugs

[John V]

Originally Posted by boggtown

If I had a lot of money to buy a torque wrench, id get a digital one. My brother made a couple in college and they are super accurate. I think they may sell kits so you can make your own, but im not sure.

Well.. yes and no. The quality digital wrenches are great, but they need to be calibrated periodically (just like a click type wrench). I agree with Jim that the beam type, though not necessarily the most convenient, are the most repeatable and trustworthy. I will never get rid of my beam type, and use it almost exclusively for critial applications like steel bolts into aluminum threads.

JV

[Tool Pants]

My short response is that all of this has been covered on Renntech. I have the 986 and 996 shop manuals. There are errors in both manuals.

You do not torque a spark plug to 22 lbs. then go back and torque it another 2 lbs. You do not torque it 24 lbs in one shot This is an error in the Boxster shop manual when it says 22 plus 2. A smiple printing/translation error. This error is not in the 996 manual. It is 22 plus or minus 2.

Another example is the size of the wrench to remove the belt. It is 24 mm on the 986 and 996. I have changed the belt on both. The Boxster shop manual says 24 mm, but the 996 manuals says 27 mm. A mistake in the 996 manual.

Porsche issue a TSB in 1994 that says not to use anti-seize. A copy of this bulletin is on Renntech. The 986/996 did not exist in 1994. But until Porsche issues another bulletin on anti-seize the mechanics are taught to follow the old.

Porsche needs to outsource its publications like other car companies. They cannot not even spell Boxster correctly on the 2001 tech intro booklet.

All of this is from my memory, so don't quote me.

[Perfectlap]

that's why I never read the manual, throw out all instuctions for video equipment, end up with 20 extra screws and washers from Ikea, Can never find the English section in user manuals and post all questions on internet forums...
scribners error...what's next?

[jwilson95]

I tend to agree with MNBoxster and Tool Pants on not using antisieze.

I sell Loctite brand as one of the industrial lines I represent for work and will ask the mfr. rep. for some "official" input on this and post it later.

Most of the issues with using it have been addressed already such as lubrication/torquing/stripping threads, etc.

See ya,

Jeff

[Tool Pants]

But I do use anti-seize on my vehicles for the spark plugs, including my Boxster. When we have a work on cars day and replace the plugs I do not use it unless the owner says ok. Not my car so I follow what the owner wants.

I have the gray and copper colored stuff, for picky people like me.

Just did it on my 1988 Toyota pickup that I have owned for 18 years.

I am old, and old habits die young.

[jwilson95]

All-

My Loctite rep. basically contradicted himself. I guess they want to sell product to those willing to use it. They have a product specifically for spark plugs, but then they have a I guess it is personal opinion/choice:



Model # : LOC37617
Item Id: 372112
Loctite 20 Gm Silver Anti-Seize Stick: Loctite Silver Anti-Seize Stick is a heavy-duty, temperature-resistant, petroleum-based lubricant compound fortified with graphite and metallic flake. Will not evaporate or harden in extreme cold or heat. Use during assembly to prevent seizing, galling and corrosion. For use in assemblies up to 1600 F (871 C). Test to Mil-PRF-907E. Suggested Applications: For easy removal of spark plugs, cylinder head and exhaust head bolts.


There is a second school of thought on using anti-seize on spark plugs; the AC/Delco spark plug installation procedure page says not to do it:
Do not use any type of anti-seize compound on spark plug threads. Doing this will decrease the amount of friction between the threads. The result of the lowered friction is that when the spark plug is torqued to the proper specification, the spark plug is turned too far into the cylinder head. This increases the likelihood of pulling or stripping the threads in the cylinder head. Over-tightening of a spark plug can cause stretching of the spark plug shell and could allow blowby to pass through the gasket seal between the shell and insulator. Over-tightening also results in extremely difficult removal.


He did say that if you use it, use it very carefully because a little goes a very long way and will get down in the chamber if it is excessive.

Let the battle rage on!


Jeff

[John V]

You don't need much. A small dab near the end of the plug will work its way up the threads as you screw in the plug.

If you tighten the plugs using the "hand tighten until seated, then one additional 1/4 turn" you'll never overtorque them.

I guess I am paranoid after seeing the results of aluminum to steel galling. Never again. I use anti-seize on my wheel lug bolts too. I remove and install wheels two to three weekends a month for the spring and summer, and being 1,000 miles away from home with a stripped stud is no fun. Been there, done that at the Peru National Tour two years ago and it sucked.

John V

[MNBoxster]

Hi,

Sorry John, to each his own...

Hand tightening and then going another quarter turn is widely imprecise for a procedure where precision is exactly what is called for to insure proper sealing, and indexing, of the plug. I wouldn't be surprised to see variations of as much as 15 ft.lbs. over 6 plugs using this method. They may never be overtorqued as you say, but they never be properly torqued either.

I do admit to having used this method in my distant past when working on motors with Cast Iron Heads (Flathead 8's, Smallblocks, and the like), but when working with Aluminum Heads (actually usually Aluminum/Magneseum alloy), proper torqueing of the plugs is key to both preventing seizure and galling the threads, and proper sealing and indexing. I have installed/replaced literally hundreds of plugs in my life using this method without a single issue. And, Porsche does not specify using anything on the threads, if this were to cause issues, they certainly would.

Fact is, the only time I ever had a seized plug requiring a Heli-coil fix was when an Anti-Seize had been previously used, so my natural inclination is to stay away from it for Plugs. I do use Anti-seize for many other procedures on the 6 cars I own and maintain.

Again, I'm averse to using it on wheel lugs as well unless specifically called for. Proper torqueing, in stages, has never left me wanting. But, to each his own...

Happy Motoring!... Jim'99

[John V]

To each his own, agreed. However if a plug seized in "due to anti-seize being used" then someone used the wrong anti-seize. User error.

[Tool Pants]

I had a plug seized in the head. It was an aluminum head. Standard copper plug with nickle plated threads. Technically that should not have happened. Pulled the head for a heli-coil. That is when I started using the stuff on plugs. That was something like 25 plus years ago. It is an old habit I have. Guess I will not go to Porsche heaven....

[John V]

Never mind that helicoils used for spark plugs are a nightmare on their own, but not a whole lot of other options....

[Uncle Bob]

I started using it in the late 60's when first building motorcycle engines. Always used a high temp lead or copper based paste. I also use it on my wheels. It's saved having the wheels bond to the hubs (alum alloy to steel). Never had a problem with it. Yes, a little goes a long way. I was taught to spread it evenly in the threads and wipe excess prior to threading.

We use it in the refinery business as a matter of course. You try removing a 2 1/8" nut that's been heat cycled to over 800F several hundred times without it....it's no different in cryogenic service. Lots of our refrigerated propane systems run at -60F and anti seize is a must.

I've read the TSB's also and take them with a grain of salt.

To each his own indeed!