Hey guys I just wanted to clarify a few things, I have a reasonable understanding of how a motor works and now I have a better understanding of how the cooling system works on a 7m, I think I’ve read nearly every post on this forum on the dreaded BHG and the cooling system
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In the past I’ve released the pressure on the radiator cap and taken it off with the motor running and checked for air bubbles in my coolant. The coolant would rise and spill over the edge of the radiator, if I brought the revs up on the motor the fluid level would drop and I could watch the coolant flow. What was different this time is at idle the coolant looked like it was pulsing, if I brought the revs up rather than getting sucked down it would shoot up out of the radiator. So here’s what I did yesterday after reading lot of threads on this stuff. I went out a checked the cooling system, all the hoses looked good radiator looked good no visible signs of coolant anywhere. Check the overflow and it’s empty! (I hate missing the simple things). I’m thinking I’m onto something here, I don’t remember checking the overflow bottle after the new turbo and injectors were put on. So I fill it to where it should be turn the heater on full blast take the cap off the radiator and start the, let it idle till the thermostat opens. It starts doing the same thing I watched it for a bit (maybe 30 seconds or so) and it starts to settle down. I topped the radiator up a little and watch it again it does the same again but not as badly another quick top up and it does it again but for not as long, it settles a goes back to normal. While I didn’t see any air come out I’m sure that’s what it was. At this point I’m just going to cap it and drive it, I’ll keep a close eye on the water and oil as well as do a block test in the next couple of weeks.
Thanks for all the help and advice.
