[Lovel]

Recently after changing the timing belts on my sons KV6 engine we found that quite quickly the non branded belt tensioner started to make a noise, so of it came again to change it to a genuine tensioner. At the same time we found a small coolant leak coming from underneath the water pump. Initially I thought it was from the impellor shaft itself, however it was not from that. The water pump was changed out for a new genuine version, but upon assembly I found that one of the M6 threaded holes actually breaks into to cooling system. Hence upon assembly we applied a sealing compound to the screws. The workshop manual does mention about using new screws with sealer on them, but they don't really state why.

Anyway tonight I was working on another KV6 and while on the bench it is much easier to see which holes have the issues, so I thought it worth taking a photo of the offending holes that break into the cooling system. You should also note that the oil pump also has one M8 hole that also breaks into the cooling jacket, and would need a sealing compound applied.

I'm sure there are a number of KV6 engines around that possibly suffer from a coolant leak after a belt change.

Photos show block with water and oil pump removed. The screw holes have been circled in white paint. All other tapped holes are either blind or tapped through but do not communicate with any other part of the coolant jacket or oil drillings.