by vornez on Fri, 15 Nov 2013 2:29 +0000
I had issues with my Hilux kun26 making knocking noises on cold mornings. This was when I used to use 10W30 fully synthetic, these days I use 5W40 fully synthetic and the knocking sounds are less noisy, they still occur, but they're not so bad and they go away quicker. When you start the engine on a cold morning, the engine preheater and the thermostat are struggling to get the engine up to operating temperature, but the thicker 10W30 oil doesn't get through the rocker cover and into the values as quickly. The injectors are also running their complex predetonation and post detonation cycles in all irony to keep the engine sounding smooth, but this doesn't agree with the poorly lubricated camshaft. There are also some other theories - using rubber washers on the injectors has caused solid objects to accumulate within the oil, which is blocking the fine mesh structure within the sump, preventing the passage of oil into the cylinders. We now use steel washers on the injectors instead.