One problem related to water pump has been reported for the 1999 Chevrolet Venture. The most recently reported issues are listed below.
In September of 2013 I noticed oil in coolant reservoir. Took to the mechanic. Closer inspection showed head gaskets were destroyed. Had the head gasket replaced and the coolant flushed out as well as changed all coolant hoses, water pump, and thermostat to the tune of $900. 00 dollars. Vehicle only has 84000 miles on it. Purchased new in 1999. Used the vehicle daily for four months when the temperature gage started fluctuating from hot to cold and found there was very little heat. Vehicle would then idle rough. Brought back to the mechanic and it appears the same issue is occurring. You've got to be kidding me. Another $800-$1000 no way. Mechanic advises this is common for Ventures. Thanks chevy looks like I'll be shopping for a Honda.