High idle

MITZI GIBBS-HARTMAN

MEMBER
2006 HYUNDAI SONATA
3.3L
6 CYL
FWD
AUTOMATIC
220,000 MILES

After replacing all four motor mounts my car runs good but at a high idle about 1200 RPMS until it goes into gear then it jerks as I change from park to drive. It is hard to keep the brake pedal depressed to fight against the idle.

Thursday, July 27th, 2017 AT 8:24 AM

5 Replies

HMAC300

MECHANIC
48,601 POSTS

If you had broken motor mounts replaced then it is likely thee is a vacuum line off or broken etc. check for that we have no diagrams of that car it may be a large line like maybe going to vacuum booster.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

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Thursday, July 27th, 2017 AT 9:37 AM

MITZI GIBBS-HARTMAN

MEMBER
36 POSTS

Car still running rough while idling in gear but not in park or neutral. Still high idle but better since cleaning throttle body. What are the odds of when the motor mounts (or last one) broke the timing chain jumped a tooth which would explain it in high idle when it wasn't before. Please advise

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Saturday, July 29th, 2017 AT 1:59 PM

HMAC300

MECHANIC
48,601 POSTS

Don't think so timing chain is inside engine if a belt maybe but would be a long shot. Scan for codes a mechanic would easily tell if a timing belt due to codes.

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Saturday, July 29th, 2017 AT 2:09 PM

MITZI GIBBS-HARTMAN

MEMBER
36 POSTS

But the check engine light is not on doesn't it need to be on to scan for codes

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Saturday, July 29th, 2017 AT 2:12 PM

HMAC300

MECHANIC
48,601 POSTS

Not really one other thing is to check for a vacuum leak like a hose off/broken due to broken motor mounts and clean throttle plate on both sides and iac hole with choke cleaner see link.
https://www.2carpros.com/articles/throttle-actuator-service