

| Subject: | VW service action |
| From: | John |
| Date: | Mon, 27 Sep 1999 11:34:26 -0400 |
All list members & especially engine builders, While looking thru the VW service bulletin index today I came across a bulletin (CMPGQLR-July '90) that covers a service action for all 86 thru 88 Vanagons. It is also discribed in a "campaign circular" (90vw06). The campaign circular says that some of the cylinder head nuts could have lost their tightness and should be retorqued. I presume VW paid for this retorquing procedure but the procedure doesn't make sense - at least to me. The procedure removes the rocker arms and intake runners to access the cylinder head nuts. Then the nuts are retorqued, not with a torque wrench but by tightening all nuts by turning them 90*. I believe this is actually a torque-angle method but that's not the point. If only some nuts have loosened, then by turning ALL nuts 90*, some nuts will now be overtightened. There is no mention of the repair manual cylinder head torgue sequence but there is a caution not to back nuts off-only tighten by 90* of rotation. The procedure reassembles everything and brings the engine to operating temperature and pressurizes the cooling system to one Bar. Engine builders help me here: Has the cyl head tightening process been changed to a torque-angle method and my Bentley(2 stages to 37 ft. lbs.)is now out of date ? If only some head nuts have loosened, wouldn't tightening ALL head nuts by 90* exert unequal clamping forces on the head, P & C assembly and overtighten some head nuts? Has anyone else ever seen VW service action TSB #CMPGQLR in the ALLDATA TSB index ? If VW had a problem with cylinder head sealing, are they responsible for engine damage for those motors that did not get this procedure performed since they made this a service action and not a recall ? Thanx, JP
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