Two problems related to check engine light on have been reported for the 1998 Volkswagen Jetta. The most recently reported issues are listed below.
In October of 2001 our engine light came on in our 1998 Jetta Volkswagen diesel. We immediately took it into srp automotive in batavia, WI, a certified Volkswagen mechanic. Over $2,000 and 4 months later the engine light still came on and now the car had no pickup. It would take about 7 miles to reach 60 mph. I picked it up and took it to motorville in sheboygan, WI, around the beginning of March. They are a Volkswagen dealer, service and repair business. I explained to the mechanic where we had it and gave him his name and number if he had any questions on what he had already tried. He spoke to steve at srp and obtained all pertinent information. Within a few weeks they had identified the problem that it was carbon buildup under the heads, a $696. 31 fix. Warren the mechanic at motorville also stated to my husband that he thought, valve seals didn't quite fit right but that was what Volkswagens part number gave them and they should be fine, bring it back in if you have any problems.
Vehicle serviced several times due to engine light illuminating, replacement of the oil and ignition cable that had shorted out did not rectify problems with the intermittent engine light coming on.