i have a '94 seville with the northstar engine . i recently got it and it showed no signs of trouble for a while. first indication i had of trouble was a low coolant level msg from the dash info area. i checked under hood found a small amount of coolant by the left side of the radiator. it turned out there was a threaded port attached to the radiator that was leaking,being the smart guy i am i figured tightening it would stop the coolant from leaking.ha! it became too bad to drive anywhere so i had it towed to shop.they replaced the radiator.next time i got coolant level msg was about 2 months later, now realise that i generally do not drive this car so it sits for extended periods of time.this time i open hood to add some coolant and found a puddle on the ground by the front right side, it was the hose leaking close to the radiator. i replaced it and refilled the coolant but did not drive it that day, a few days later i got in and drove it about 15 highway miles and after 10 it said check coolant level by 15th mile it was saying engine hot and i pulled over for it to cool. i added some coolant and drove it to a shop where i was told sometimes these closed cooling systems need to be babied into getting full. the system took a while to fill and i was on my way it seems the temp was about 219 for the most part. a few days later i was going to use the car for a trip and was doing my errands when it said check oil level. within a few minutes it said check coolant level i was about 4 miles from home when it began and went straight home just before i got home the msg read engine hot .the next morning i went out and looked in the radiator and sure enough it was low on coolant so i topped it off.then remembering the oil warning i checked the oil and found the level to be at the top end of the dip stick like about a foot above the mark and the oil was looking like creamy coffee . so my coolant has gotten into the crankcase. i got a guy from a shop to look at ,it he tells me the steel cylinder inserts in the aluminum block are sealed with some sort of o-rings and they will never seal again due to block warpage and the coolant will just run thru into the crankcase again .does anyone have an idea what the actual problem is with this engine and if so, is it repairable or is that economically feasible to consider?