- Dec 17, 2005
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- VF S1 SV6 STORM A6: VZ S1 SV6 A5
Gave the 2004 VZ SV6 a filter and oil change recently. Went to remove the screw cap from the oil filter body and as usual it was very tight. Over the years the cap has always been very hard to undo as I usually torqued it to 25nm as per the manual. I had torqued the cap to 18nm at the last oil change approx. six months earlier, to see if the release effort was reduced. The removal effort this time was still excessive. I now wonder if the moulded nut could shear away from the casting. I have a high capacity torque wrench and slowly stepped it up until the cap released. It finally released the cap at 90 ft/lbs about 126nm. About 5 times above the tightening specification. The thread on the cap is relieved to let oil gain access to the threaded section. Is the cap thread stretching over time and should it be replaced? This self tightening action seems a recipe for the cap failing at some time down the track, especially if fatigue cracks start and are not noticed. Should the cap be nipped at eg 5nm -10nm? I guess Holden technicians see this fairly often with the VZ and VE Alloytecs. Does anyone know of a fix for this problem ? Otherwise is the only solution to fit a new filler cap and/or filter body?