Good evening.
I'm hoping for some experienced A2OC forum member to help me work out what I need to do to repair my A2 before I simply end up slinging money at the problem.
The story:
On Friday my partner drove about 18 miles home from work, and about 10 miles in noticed steam coming from the engine compartment. When she got home she called me asking if she was alright to keep using the car, and I advised her to check the coolant. She told me that as she opened the cap some coolant sprayed out of a hole on the side, and I advised her to walk for the time being.
When I got home I found the coolant expansion vessel mostly empty (a good 3cm or so below the minimum marker), and also there was some coolant under the car and lots crusted around the seam on the expansion vessel. On Saturday I topped up the coolant and plugged in my ODB2 dongle so I could monitor the temperature, then ran the car at idle for 15-20 minutes. The temperature crept up on the dash, but lagged behind the coolant sensor, and when the coolant sensor reached about 95C the dash still only said 90, and the radiator fan did not start as I had expected it would. In this time the coolant level had not shifted, so perplexed I came to these forums and researched as much as I could and read about the dreaded head gasket failure.
A friendly neighbour came by and checked the oil for signs of head gasket failure, but the oil showed no sign of emulsion although it seemed rather low (but as my drive is on a slant it might just have all run to the rear). When I revved to 3k rpm there was a fair bit of water ejected from the exhaust, but it did not appear to be coolant. Running the engine on idle it slowly crept up to 105C but the coolant did not boil, nor spill. I recalled reading on the forum that the air con affected the radiator fan and when I turned it on the fan did spring to life. Throughout, the radiator did not appear to be getting very hot, but still no change in coolant level.
A quick top up with some oil and a brief drive on the roads, and while the coolant temperature edged up to 100C the coolant level did not change and no steam was observed. A longer Sunday drive of about 8 miles with careful monitoring of the coolant temp via ODB2, pushed the temperature up to 112C, at which point my partner swore she saw smoke/steam and I pulled over. Now a great puddle of coolant formed under the car, and looking into the engine bay coolant could be seen sloshing about in the under tray, and the coolant in the expansion vessel had dropped to about the same level as seen on Friday.
My diagnosis is that there is some crack in the expansion vessel that opens when it is hot, and dumps out all the coolant. But before I spring for a new expansion vessel, does anyone have any differential diagnoses?
I'm hoping for some experienced A2OC forum member to help me work out what I need to do to repair my A2 before I simply end up slinging money at the problem.
The story:
On Friday my partner drove about 18 miles home from work, and about 10 miles in noticed steam coming from the engine compartment. When she got home she called me asking if she was alright to keep using the car, and I advised her to check the coolant. She told me that as she opened the cap some coolant sprayed out of a hole on the side, and I advised her to walk for the time being.
When I got home I found the coolant expansion vessel mostly empty (a good 3cm or so below the minimum marker), and also there was some coolant under the car and lots crusted around the seam on the expansion vessel. On Saturday I topped up the coolant and plugged in my ODB2 dongle so I could monitor the temperature, then ran the car at idle for 15-20 minutes. The temperature crept up on the dash, but lagged behind the coolant sensor, and when the coolant sensor reached about 95C the dash still only said 90, and the radiator fan did not start as I had expected it would. In this time the coolant level had not shifted, so perplexed I came to these forums and researched as much as I could and read about the dreaded head gasket failure.
A friendly neighbour came by and checked the oil for signs of head gasket failure, but the oil showed no sign of emulsion although it seemed rather low (but as my drive is on a slant it might just have all run to the rear). When I revved to 3k rpm there was a fair bit of water ejected from the exhaust, but it did not appear to be coolant. Running the engine on idle it slowly crept up to 105C but the coolant did not boil, nor spill. I recalled reading on the forum that the air con affected the radiator fan and when I turned it on the fan did spring to life. Throughout, the radiator did not appear to be getting very hot, but still no change in coolant level.
A quick top up with some oil and a brief drive on the roads, and while the coolant temperature edged up to 100C the coolant level did not change and no steam was observed. A longer Sunday drive of about 8 miles with careful monitoring of the coolant temp via ODB2, pushed the temperature up to 112C, at which point my partner swore she saw smoke/steam and I pulled over. Now a great puddle of coolant formed under the car, and looking into the engine bay coolant could be seen sloshing about in the under tray, and the coolant in the expansion vessel had dropped to about the same level as seen on Friday.
My diagnosis is that there is some crack in the expansion vessel that opens when it is hot, and dumps out all the coolant. But before I spring for a new expansion vessel, does anyone have any differential diagnoses?