2000 VW. Jetta with 148.000 miles, 4 cyl. manual front wheel drive.now it seem after replacing the spark plug, air filter, and gas filter that it is something to do with the temp. it is when ran next to 30 minutes the temp guage reaches 290 f. or full the alarm sounded, I did pull-over and key off, it is will a few munutes and start open it is the temp guage reaches half again this is problem all time.

NOTE: It is never has replacing timebelt and water pump