2009 S600 W221 P0300 Random Misfire
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Joined: Sep 2020
Posts: 88
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2007 S65
@johnnyrocket52 I wonder if you have the torque specs wrong. See my attachment. 4Nm is the first stage of tightening and then I read that you go an extra 120 degrees from that, which I measured to be about 13Nm on my torque wrench!
I didn't initially know which engine I had so I just tightened mine down to 10Nm but I think I'm going to go back in and quickly tighten them up just a little more per the spec there. If anyone sees that I'm reading this wrong, please let me know.
I didn't initially know which engine I had so I just tightened mine down to 10Nm but I think I'm going to go back in and quickly tighten them up just a little more per the spec there. If anyone sees that I'm reading this wrong, please let me know.
I think I'll sinch mine down to 11Nm and call it good, but I still think 4Nm is likely too loose based on the service manual.
Thread Starter
Member
Joined: Jun 2023
Posts: 190
Likes: 76
From: Portland, Oregon
2009 S600 V-12
@johnnyrocket52 I wonder if you have the torque specs wrong. See my attachment. 4Nm is the first stage of tightening and then I read that you go an extra 120 degrees from that, which I measured to be about 13Nm on my torque wrench!
I didn't initially know which engine I had so I just tightened mine down to 10Nm but I think I'm going to go back in and quickly tighten them up just a little more per the spec there. If anyone sees that I'm reading this wrong, please let me know.
I didn't initially know which engine I had so I just tightened mine down to 10Nm but I think I'm going to go back in and quickly tighten them up just a little more per the spec there. If anyone sees that I'm reading this wrong, please let me know.
Member
Joined: Sep 2020
Posts: 88
Likes: 20
2007 S65
Normally it isn't, but check my attachment and the torque specs at the end. Two stages of torquing, the second appearing to be a rotational degree value.
Member
Joined: Sep 2020
Posts: 88
Likes: 20
2007 S65
The proper way to do this, per the tech, is to replace each of the bolts with a brand new, unstretched bolt, and torque it to 4Nm and then rotate 120 degrees after achieving that torque. If the valve covers need to come off in the future, the bolts should be replaced then, as well.
I have ordered replacement bolts and will be performing this when they come in, in a few days. I'll update the forums if I learn anything else.
Thread Starter
Member
Joined: Jun 2023
Posts: 190
Likes: 76
From: Portland, Oregon
2009 S600 V-12
On second thought, I think I missed my opportunity to do this right by initially torquing mine down to 10Nm. I think Mercedes did this spec so that the servicer would get resistance to 4Nm on a new gasket and THEN go 120 degrees past that, so on mine that were already torqued down to 10Nm, I think backing them off and then screwing them in until 4Nm resistance is working with a pretty squished gasket already, so 13Nm is probably too much and I expect doing this right with a fresh gasket would've yielded 10 or 11Nm worth of torque. I'm sure I'm being overly technical about it, but after an oil leak on finger-tight bolts caused me $2500+ worth of work, I'd like to get it right.
I think I'll sinch mine down to 11Nm and call it good, but I still think 4Nm is likely too loose based on the service manual.
I think I'll sinch mine down to 11Nm and call it good, but I still think 4Nm is likely too loose based on the service manual.
Still no fresh oil weeping down from cylinder head gaskets.
I hope the 120 degrees past 4Nm works with new bolts and you don’t strip any bolts.
Keep us posted.
JR
Last edited by johnnyrocket52; Aug 19, 2025 at 02:35 AM.
