FINALLY got the Suzuki service manual for my 2006 S40.  So, I am completing a couple of 600 mile items which I did not have enough data to  complete at the time (now at 750 miles).  I am currently working on the head torque.  I have yet to pull the cover and am wondering at the sense of it all.

I checked the two exposed 9mm bolts ~ 25 lb-ft with my trusty torque wrench - not a budge.  I don't have a crow foot wrench to fit the ones under the intake and exhaust ports so I use a box wrench and give them a calibrated tug - not a budge.  The two small ones on the bottom right side of the cylinder - moved just a little tweak.

I wonder if it is worth removing the 247 bolts from the head cover to check the other 2?  I do not recall ever retorquing factory head bolts  on anything - car, truck, motorcycle, tractor, lawnmower etc.  

The manual states "Apply engine oil to the four 9 mm nuts and retighten..."  Firstly, engine oil will not penetrate the exposed acorn nuts and copper washers which are compressed under the nuts - at least not before next year.  The internal nuts are already exposed to engine oil so what is the point?  Secondly, does "retighten" imply that one is supposed to un-tighten the bolts first?  This is definitely un-cool. Perhaps the authors had partaken of a little too much Sake while working on this chapter.

Comments, flames, advice?  TIA

Regards,

Ken

I too agree with Lancer.  First, you cannot properly torque a nut without first backing it off to below final torque specification.  The breakaway torque of a nut is usually higher than the proper set value.  Second, the manual specs are for oiled threads and washers.  To do this properly you would have to back off all nuts to expose the threads.  That's not a good idea as, if you do one at a time, you risk distorting the sealing area.  If you back off all evenly then you have removed all sealing pressure on the head gasket that is also not a good idea.  So, what I did on mine (and my wife's) was to back the four big nuts plus two under-head nuts off between 1/8 to 1/4 turn in a criss-cross pattern then retorque to spec, without oiling.  The nuts ran back up to almost exactly where they were in the first place!  So I would say just check them for tightness whenever you are working in the area but otherwise don't make this a ritual service.  The only nuts I've found that did tighten up some when retorqued to spec were the exhaust manifold pair and the small cylinder base nuts.

I went and did it, because I didn't want any warranty issues, and because I was curious what lay beneath. I did loosen them, oil the threads, and re-tighten.
For what it's worth...

I don't see how that would void the warranty. The auto makers used to try that crap years ago, but back when we had a government that cared about ordinary people, a law was passed banning that, as long as the owner performed the work properly and documented that they did so somewhere (I noted it in my owner's manual).