Has anyone ever come across a front belt on the KV6 that is too tight ?
Has anyone came across a failed KV6 tensioner ?
Here's my story so far.
Removing the front upper left and right timing belt plastic covers, I tried twisting the belt but to me it seems there is not much movement if any TBH. It does not seem typical of a KV6 and there is a general low pitched whine about the engine at idle that disappears when revved. The roller tensioner is free to rotate on its fulcrum. All other idlers or water pump pulleys are new and were replaced using original INA components (ie the original stuff that MGR fitted) Despite the new components there is a distinct idle speed whirr that I know should not be there.
I can eliminate the engine because itself because this one is a replacement, the only common denominator is that the old engine had just recently had the same (new) timing components on it and it too had this low whirring noise, so there is something in common that I have carried over from the old engine and its not going away.
As a comparison I have recently changed another KV6 timing belt system of late and the running tension with new belt fitted is what I would class as normal, and of course it is whisper quiet as one would expect.
Many years ago I recall changing a belt on a K series with manual tensioner where I had inadvertently applied too much tension to the belt, and the noise with the engine running was similar to my ear anyway. That's why I am suspect of this fellow below in the KV6, but find it hard to understand why that design of tensioner can lead to over tensioning as I assume it is just a simple plunger and spring arrangement. (perhaps some hydraulic damper arrangement also?) Surely the failure mode for this would be to not tension enough rather than over tension?
