1998 Volkswagen Jetta Idling Problem

1998 VOLKSWAGEN JETTA
20,000 MILES • 6 CYL • FWD • MANUAL
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BWILLI1
  • MEMBER
  • 1 POST
2.8 V6 98 VW Jetta
The engine will not idle when cold and after it is warm the idle is low. What do you think is the
problem area? I replaced the seal behind the oil cooler on the car and that's all.
Jun 1, 2009 at 11:23 AM
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KHLOW2008
  • CAR REPAIR CONTRIBUTOR
  • 41,814 POSTS
Hi Bwilli1, Thank you for the donation. When engine is unable to idle at cold start, it could be due to a faulty Engine Coolant Temperature sensor. When idling speed is low arfter warming up, insufficient air is getting past the throttle valve. The throttle valve could be clogged resulting iin insufficient air getting past. Spray some carb cleaner into the throttle valve and use a rag to scrub it clean.


https://images.2carpros.com/forum/automotive_pictures/192750_ThrottleValve98Jetta01_1.jpg


https://images.2carpros.com/forum/automotive_pictures/192750_ThrottleValve98Jetta02_1.jpg

Another possibility is vacumn leakages between the Mass Air Flow sensor and it could be due to cracks in the air hose or faulty PCV, A dirty MAF would also cause the symptoms described. Use a suitable MAF spray cleaner to clean and retry.
Jun 1, 2009 at 1:59 PM
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