hey guy im new to the forum, i just picked up an 89 240 hatch a few days ago. The guy said it tried to overheat on him a few days earlier, tightened a hose, and fixed the problem. I drove the car 200+ miles back home without any sort of leak, or overheating. Then drove it another 15 without a problem. So get in it today and about 10 minutes after being in it, it starts leaking coolant/water. I go to walmart, buy some coolant, fill it up, and drive it to the bank, and look under my car and its leaking really bad, like a huge puddle just in a matter of seconds, so i bring it home, let it cool. Fill it with water, run it for a few minutes, not 1 drop leaking anywhere, then i take it down the road a few miles, still nothing. This doesn't make sense to me, i've never heard of a leak that only happens sometime. I tried to find where it was coming from with no luck. Any ideas, is this a common problem. Maybe some valve got stuck open or something. Im clueless. Seems to me it should leak heavily when full, then slowly stop the more it leaks, but its topped off now and holding every drop

 

also might be worth mentioning, when i drove it 200+ miles it had water in it, then when it was leaking really bad today, it was after i had put antifreeze in it. Now once again, it has water. seems the antifreeze leaks much faster, might just be a coincidence

 

not sure if this could be it, but maybe while the antifreeze reacts differently to the pressure (it may expand more??) and cause coolant to come out easier? i duno that weird it only happens sometimes. try to find where the leak is coming from, that would help.

 

yeah, make sure your overflow tank isnt over filled