In the past when fitting spark plugs I have always tightenned to a specified torque and left it at that. I have just bought Bosch 0 242 236 562 and the box and manufacturers spec sheet says 28Nm but also says 90 degrees. Can anyone advise the correct way to tighten them?
tightening spark plug
- Thread starter Magicarcher
- Start date
Mister T said:
I still don't get it. do I do 28Nm then turn another 90 degrees? seams a lot.
patriot66 said:I'm fairly certain it's 28Nm OR finger tighten +90 degrees
Thanks Patriot, that makes a lot more sense. I've always used a torque wrench never come across +90 before.
Torque angle tightening is common with single use "stretch" bolts. I remember buying one of these when I rebuilt a Rover K-Series engine.
Laser 2611 Torque Angle Gauge - 1/2" d https://www.amazon.co.uk/dp/B0039ULM2I/ref=cm_sw_r_cp_apa_i_hMPMCbWX2WY9R
For Z4 spark plugs, perhaps they are aluminium and stretch-torqued, depending on cylinder head material.
Laser 2611 Torque Angle Gauge - 1/2" d https://www.amazon.co.uk/dp/B0039ULM2I/ref=cm_sw_r_cp_apa_i_hMPMCbWX2WY9R
For Z4 spark plugs, perhaps they are aluminium and stretch-torqued, depending on cylinder head material.
ben g said:
I went to tighten number 1 spark plug like that and bottled it because it seemed very tight and TBH I'm concerned that some of the thread is going to come out when I come to change it next time
What's more the snap I included is from the BMW service manual and it says to torque to 23 or 30 Nm depending on the plug size and does not mention angle tightening.
Finger tight then 90 degrees is what I've always taken as a safe tightness, never had any detonation nor stripped threads. Either do that, or use the torque above. Do not tighten to 28nm and then do another 90 degrees, unless you want to strip the thread in the hole...