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rpmdiag, Tech and Instructor
Category: Car
Satisfied Customers: 8064
Experience:  Since 1975
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2009 hyundai sonata: v6..cold start idle is erratic..rpm..drops

Customer Question

my 2009 hyundai sonata v6 cold start idle is erratic. the dealer gets it right for a day or two then it starts again. when I start it up on a cold day, 32 degrees, it runs up to 2100 rpm, drops to 1000, and fluctuates between the two several times in the first 5 seconds after start. after 1 minute warmup when i drive away it lurches and then almost dies until warm. The dealer did the service bulletin fix on the cold start and that helped for three days then right back again. What are we doing wrong?
Submitted: 8 years ago.
Category: Car
Expert:  rpmdiag replied 8 years ago.



The bulletin was probably done incorrectly, have them do it again.