I noticed recently that my temp gauge didn't seem to be working properly and then quickly jumped to overheat.
I checked the thermostat which is OK, then checked the coolant level which was very low, so after checking for leaks I found a spot at the back of the block (I'm facing the engine from the front of the car) just to the right of the oil filter where the coolant was leaking.
There is a black metal cap on the block just above the oil pan, I haven't found any info as to what this cover is for, but it appears to be the location for the leak.
Very difficult to see or access.
Can someone tell me what's behind this cover???????

thanks John