Saturn Repair: cooling system, losing coolant, radiator cap

Question
I've got a 97 SL2 with abt 90,000. At abt 80,000 it developed a small leak at the top of the radiator. Overheated one time due to a bad water pump that was repaced. car ran fine for several months, then started losing coolant. I assumed the patch on the radiator had gone bad, or the crack had gotten bigger and re[placed the radiator, but I still seem to be losong coolant.Could a bad resivior cap be responsible?

Answer
Hi Lynn,
I don't think it is the resevoir but more likely something else, perhaps a more serious problem.  This Problem is more common that you'd guess with the SL2 engine and the cause is really quite a mystery.  To date, I haven't been able to pin it down but some have had luck with replacing the water pump.  But, you already did that.  That doesn't mean it is not the problem.  That new one could have been off spec or have gone bad in the short time you've had it.  On more than one occassion, replacing the radiator cap (not the typical cap you'd expect) fixed the problem for me.  The CAP is on the resevoir itself (big black plastic cap).  It is sensative to the pressure in the tank and if it is leaking, even slightly will allow the coolant to 'boil off'.
The easiest fix is to replace that. It is about $13 at AutoZone or similar auto parts stores.
Sorry I can't help you better.
Best of luck with it,
Greg Moore
www.taylorgolfsupply.com
www.knockout-band.com