Just going by BMW North America's written instructions.
http://bmwtechinfo.com/repair/main/index.htm
I have not studied these recommendations in quite some time, but sight unseen, I have to wonder whether this advice refers to newer style stretch head bolts versus the non-stretch/reusable bolts that were originally used with the E9. (
I wonder if the same factory admonition is given for early E21 installations.)
As methodology seems to be changing, I would be inclined to follow the gasket manufacturer's recommendations over the factory's dated instructions. That presupposes the gasket is a fairly new one :wink:
Anecdotally, the Autobooks Manual was written prior to the factory's change of recommendation to torque-to-yield bolts. It clearly describes "slackening" the bolts prior to retorquing. Same recommendation is found in original shop manual.
http://www.e9-driven.com/Public/Library/BMW-E9-Manual/pages/en/11121010.html#refertoc
http://e9coupe.com/forum/showthread.php?t=7312
http://e9coupe.com/forum/showthread.php?t=10288
So - in response to Rohan's original query, I would first want to know what fasteners were used for the last head installation. Then I would be interested to know whether the original gasket manufacturer recommended any retorquing.
Practically speaking, if you were careful with the torque wrench, it is doubtful you would hurt anything by retightening the headbolts within approximate recommended specs. This assumes there was no debris interfering with the bolt threads and that the headbolts were not distorted. Unless you discovered that one or more of the bolts were mysteriously loose, retorquing is unlikely to remedy what is probably a headgasket issue. I use the word
probably, because there is always the remote possibility of a head defect. I also would wait to carefully inspect the head before concluding that the problem is related to the early head design. Some of us (me) continue to use them on a daily basis. :smile: