That clears up any confusion!
Got it.It's used for torquing bolts to a yield point, which slightly stretches the bolt, providing an optimum clamping action. The bolt cannot be used again.
The bolt is tightened to a specific torque value, and then tightened further to a specified angle. The wrench has an angle measuring device, almost like a protractor.
Hmmm...it's listed as a OEM NGK BKR6 EQUP.My E46 Bentley manual states plugs are to be torqued to 25 NM (18 ft-lb.)
Wingspan, does your E46 use a 12mm spark plug?
I love this type of real-world autopsy information!experiment using a junk Ford engine
Hello Cam.A little dab of anti-seize on the threads will not do any harm.
Just reduce the torque a bit.
NGK should have published two separate torque values, one for dry and one for anti-seize installation.
Best is to remove spark plugs every 2yr or 24K or so for examination and apply a dab of anti-seize to prevent bonding.
I have done this for 30 years and always use 25 Nm, never have a single problem with all my cars.
Great help .... "I think".I think I used a 17mm to do the plugs (M54 engine), but I'm not sure.
???? You don't need to remove the valve cover to change plugs.Hello Cam.
Actually this would force you to change the VCG and the grommets too.
Different motor, different head does not make a specification for a BMW head.I used a scrap Ford 2001 MY PI 2V V10 head with good threads to test the breaking point of the plug threads that are so weak according to many people on this forum.
I did four plugs, two with antiseize and two dry.
I started with the correct torque and worked up.
At 55 ft lbs it felt like the threads were just starting to stretch.
From 55 to 85 I got about 1-1/2 turns more out of them, and it did not feel good.
Two of the plugs snaped off flush with the heads just shy of 100 ft lbs, after anouther 3/4 turns from 85 ft lbs. One was dry and one had anti seize.
The third plug broke right at of 100, 5/8s of a turn after 85 ft lbs. This one had anti seize.
The forth made it to 115 ft lbs, 1/8 turn past 100 ft lbs (7/8s of a turn passed 85 ft lbs) and snaped. This was a dry plug.
Every one of them the plug broke, I never striped the threads out of the heads like I though I would.[/i]
Yup. Brain fart.???? You don't need to remove the valve cover to change plugs.
A quick google search shows that this is aluminum head.Different motor, different head does not make a specification for a BMW head.
It's not stated if cast iron, compacted iron or aluminum head.
+1. AND, you really cannot trust the accuracy of a torque wrench at that low of a setting unless it is rated in in/lbs. Most torque wrenches are rated for accuracy in the upper 80% of their adjustment range. So use at the bottom of setting....at your own risk! So do not use the typical 15lb to 150lb wrench for spark plugs.Most damage done by amateurs (when changing sp plugs) is from cross-threading, and not so much from over-torque.
I'll bet you, even guarantee you that the design of the plug holes in each head are different and therefore the results do not apply to BMW head.A quick google search shows that this is aluminum head.
99.999% of cars out there use Aluminum head.
I understand that this is Ford and not BMW but when it comes to cyl head spark plug hole aluminum threads, they are very similar in principles.
The bottom line is: there is some margin for safety when torquing sp plugs according to BMW guidelines.
Most damage done by amateurs (when changing sp plugs) is from cross-threading, and not so much from over-torque.