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DISCUSSION => Engine + Driveline => Topic started by: Isamemon on January 30, 2009, 02:16:54 PM

Title: head torque
Post by: Isamemon on January 30, 2009, 02:16:54 PM

book I have says for a 91 318 with a M42 is  ( in steps) to torque the head bolts to 22-25 lbs, step 2 turn 90-95 degress, step 3 90-95 degrees
is this correct or has this been updated
doing this saturday

Title: head torque
Post by: KenC on January 30, 2009, 03:29:51 PM

That's correct.  Make sure you have the correct torquing pattern as well.  And hold the wrench position for a few seconds after you tighten them.

Title: head torque
Post by: papercutout on January 30, 2009, 05:46:42 PM

Having just done mine any being 100 miles into the 500 before we check it again, is there any tightening to be done, just to re-torque the head at 500ish miles?

I'd like to be safe, and the printout results of tightening procedure didn't mention it!

Thanks.

Title: head torque
Post by: Isamemon on January 30, 2009, 09:29:19 PM

I was also PM'd that between each stage to let it sit for 10 minutes :confused:

Title: head torque
Post by: papercutout on January 31, 2009, 05:05:31 AM

That 10 mins is the time it takes you to reposition yourself round the engine bay ;) (doing it with a friend is a lot easier btw)
In reality, I have no idea if leaving it makes a difference, so don't ask me, we just did it.

Title: head torque
Post by: nomad on January 31, 2009, 08:43:53 AM

It is a torque bolt that stretches a certain amount when you get that pressure on it.
There is no real torque number so you can't "retorque" after a while. What would you do to make sure it is tight? Can't do another 90* you know what I mean?

I waited a little while in between stages, I also soaked my head bolts in motor oil as the book says so that they turn smoothly to the torque point. I had one that apparently didn't have enough oil on it and it chattered a bit at the final 90*. Kinda scared me but i decided not to take all of them out and redo. It go to the correct point.

The only thing i did was cheat by not buying the dial gauge/protractor, I used my finger since the angle is an easy one to remember. Yeah, ghetto like that...

Title: head torque
Post by: papercutout on February 05, 2009, 02:33:54 PM

Is that the answer then, they don't get re-tightened at 500 miles or so? Makes life easier, but kinda feels wrong!

Title: head torque
Post by: KenC on February 05, 2009, 06:23:00 PM

They're expansion bolts.  Don't retighten them.

Title: head torque
Post by: nomad on February 05, 2009, 07:14:11 PM

yep, that's the answer