Took the Z4 2.0 2006 out for a spin on my country roads two days ago and drove like a dream. However, towards the end of the drive I smelt a weird smell and by the time I got home had steam pouring from under the bonnet. NOT GOOD.. Weirdly the car never overheated but that's by the by. It wasn't a long drive maybe 5 or so miles.
When she cooled down a wee bit I filled her back up with water and run her up to temp with the cap off keeping an eye out for bubbles coming from expansion tank,(evidence of blown head gasket) there didn't appear to be any. When the water heated up in the block to what must have been near boiling point at the block the water surged up and flooded out of the expansion tank with great gusto. I tried this procedure with the cap on BTW with similar results in that pressure would build up and steam came flooding out. My first thoughts were blown head gasket but after deliberation I wandered if it could be water pump or thermostat. One thing I did notice is at the top of the expansion tank, Which is relatively new, was that there used to be small stream of water inside the tank and near the very top. I believe this is to help clear air locks, not sure if I am correct on that one. However since my new episode I did not see this small stream of water any more.
I believe my car has a mechanical pump and not the new electrical, again I am not 100% sure about this.
Would either a stuck shut thermostat or failing water pump cause this dramatic issue or is there a possibility my head is blown..
When she cooled down a wee bit I filled her back up with water and run her up to temp with the cap off keeping an eye out for bubbles coming from expansion tank,(evidence of blown head gasket) there didn't appear to be any. When the water heated up in the block to what must have been near boiling point at the block the water surged up and flooded out of the expansion tank with great gusto. I tried this procedure with the cap on BTW with similar results in that pressure would build up and steam came flooding out. My first thoughts were blown head gasket but after deliberation I wandered if it could be water pump or thermostat. One thing I did notice is at the top of the expansion tank, Which is relatively new, was that there used to be small stream of water inside the tank and near the very top. I believe this is to help clear air locks, not sure if I am correct on that one. However since my new episode I did not see this small stream of water any more.
I believe my car has a mechanical pump and not the new electrical, again I am not 100% sure about this.
Would either a stuck shut thermostat or failing water pump cause this dramatic issue or is there a possibility my head is blown..
