I heard some noises I didn't like so on a weekend full of torrential rain I popped off the cam chain covers to take a look.
LHS
RHS
The Bentley says something like 'use screwdriver to lever the idler arm, should be no movement'.
My question is : what is the right amount of resistance in the tensioner? The bentley shows testing by levering down the LHS tensioner against the case. I don't need to lever - pushing directly on the idler arm downwards I can move the idler and can see the chain start to lose tension - I assume this one is in need of rebuild. I plan to purchase a rebuild kit and fit collars instead of going the pressure-fed route.
On the RHS there is no place to lever. Pushing down on the idler arm with the same amount of force as the LHS doesn't budge the tensioner at all. How much pressure should I be putting down?
Side Note : where does the diesel-at-idle rattling come from? I can see no evidence of chain contact with any part of the case. There is no debris in the case (in fact it is very clean as per pics). I can't really see the chain guides under the chain but I see no signs of degradation anywhere.
Any tips on checking for wear/tear in the chain/ramps/tensioners welcome.