Jetta GL with 2.0L engine surges when idleing, rpms go up and down. When comming to a stop the the engine is around 2000rpms and then slowly drops to normal and begins hunting up and down from 1000 rpms. Checked vacuum lines, etc did not see anything abnormal. Can anyone shed some light on troublshooting this problem.
TIA
I removed to top of the air cleaner to check the MAF, it looks good, very clean and the reed is centered. The rubber intake tube from the engine has quite a bit of oil in it. I assume this is not good, anyone know how to fix this. Oh, I also plan to remove and check to IAC valve to see if this is contributing to the idle problem.
the most common answer to your problem i see is that the throttle body needs cleaning. a build up of gunk does not allow the idle adjust to adjust the idle smoothly. it is said to spray out the throttle body with carb/throttle body cleaner. this is done off the car. i need to do this myself as mine hunts a little, too. it is a common problem and fix.
the oil in the air intake b/w the filter and tb is also very common. i believe it comes from the condensation of oil vapors from the pcv valve after shutdown. these vapors are usually vented to the intake and burned instead of being liberated to the atmosphere as pollution. there are a couple of fixes for this. one is to install an elec. valve that closes the path after shutdown and the other is to vent to atmosphere (not PA). it is not generally a problem unless you let it build up so much that it contaminates the maf. it's probably best to just leave it alone and clean it out from time to time. mine just had a little oil scum after 95,000 miles.
i suppose the second prob. addressed here contributes to the first. just a little periodic maint. should do the trick.
anyway, i could be wrong. see what else you get. also try a search on google/groups/rec.autos.makers.vw.watercooled and vwvortex.com. both resources are great and you will find many posts on your questions.
in all, it sounds like you don't have much to worry about.
have a good day, buddy.
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