punctualalex
Member
Background: 2003 Jetta TDI, ALH engine, 228k miles, 5spd, totally stock. Starts fine in all weather, no CEL, no other big issues. The mechanic did mention there's a vacuum line kinked right at the firewall that could probably be replaced. Last maintenance was a replacement thermostat and coolant temperature sensor about 3k miles ago, although this problem occurred before I replaced all that stuff.
Problem: On the first start after it's been sitting for a while (usually overnight but occasionally after a 9-hour work day sitting in a hot parking lot), it will fire up right away but the RPMs will pulse/surge/bounce between about 800 and 1000. After ~30 seconds or ~10 bounces (longer in the cold) it smooths right out to the usual idle of 900. No issues while driving, only at idle and only right at first.
Video: https://www.youtube.com/watch?v=O8cJYlno2Eo
Question: Is this anything to worry about? Is it an actual problem, or an idiosyncrasy of an old vehicle? If it does need to be fixed, how do I fix it? I'm handy with the usual tools, but the only other info I could find about similar issues had to do with injection quantities and that is way outside my skill/tool set.
Problem: On the first start after it's been sitting for a while (usually overnight but occasionally after a 9-hour work day sitting in a hot parking lot), it will fire up right away but the RPMs will pulse/surge/bounce between about 800 and 1000. After ~30 seconds or ~10 bounces (longer in the cold) it smooths right out to the usual idle of 900. No issues while driving, only at idle and only right at first.
Video: https://www.youtube.com/watch?v=O8cJYlno2Eo
Question: Is this anything to worry about? Is it an actual problem, or an idiosyncrasy of an old vehicle? If it does need to be fixed, how do I fix it? I'm handy with the usual tools, but the only other info I could find about similar issues had to do with injection quantities and that is way outside my skill/tool set.