Have I damage my engine? On the way back from Winton Raceway today, with the aircon on high, the temp gauge in mid range and all of a sudden a hose or something in the engine bay poped with a hisssing sound. Stopped the car immediately on the side of the Hume and noticed a small amount of smoke coming out the from the hood. Poped the hood open and noticed some coolant at the back of the engine bay, some next to the battery, under wheel guards and next to the reserve tank. Drove the car for about another 200m to exit of the highway to get away from fast traffic, engine started to make funny noises, stoped the car immediately and switched off the engine. Checked radiator was empty but the reserve was almost still full. Tried to see if any hoses were broken or loose but could not see any. Toll truck to the rescue. What has happened? Is my engine OK? Anyone got any ideas?
Take it to a mechanic, fill with water, pressure test the cooling system to identify the leak. Go from there.
How were your engine temps through this ordeal? If your radiator was empty, there will be no fluid to get an accurate reading off the temp sensor. Its either a BIG leak (draining the system within a minute), or a slow leak that went unnoticed for a long time. I would look at yopur heater core pipes on the firewall, as well as under plenum hoses if still connected. You need to be real careful in an overheat situation, as turning the car straight off when it is red hot can cause the piston rings to weld themselves to the cylinder bore through heat alone.
Don't think it was a slow leakage, was driving with the aircon on, the aircon started to loose it's coldness and then heard a hisssing sound come the engine bay, was all pretty instantaneous. I didn't switch the engine off immediately, but not sure if it was a good idea to drive it another 200m to exit the Highway. Anyway, am lucky to have a mechanic next door at work, so will get them to check it out. Hope I haven't done too much damage.
Temp was at mid range on the guage before the incident and high after the hissing, but not sure how accurate it is.
Are you sure the AC went warmer? Was it a white smoke that smelt funny? My AC de-gassed itself when the system let go a while back, I thought the engine was on fire. Is it possible that the rad was just low, and the AC shat itself instead? The cooling system would not tend to 'pop' unless something really noticable happens like this>> http://www.aus300zx.com/forum/showpost.php?p=965198&postcount=1
No, not quite as bad as that, just alot of coolant around the passenger side wheel guard and some in around the battery tray and back wall of the engine bay. Don't understand why there was still an almost full coolant reserve though.
A leaking main coolant system will suck air into the system in preference to the overflow. There is a number of ways to test the cooling system integrity- your nextdoor mechanic will have no problems doing this.
