# Volvo idles erratically

**URL:** <https://community.cartalk.com/t/volvo-idles-erratically/5684>\
**Category:** Maintenance/Repairs\
**Tags:** volvo\
**Created:** [October 9, 2007, 12:26am UTC](https://community.cartalk.com/t/volvo-idles-erratically/5684 "2007-10-09T00:26:11Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mesp1951](https://avatars.discourse-cdn.com/v4/letter/m/8dc957/32.png) [@mesp1951](https://community.cartalk.com/u/mesp1951)\
**Post date:** [October 9, 2007, 12:26am UTC](https://community.cartalk.com/t/volvo-idles-erratically/5684/1 "2007-10-09T00:26:11Z")

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1987 Volvo 780 with 118,000 miles idles fine when engine is cold. However, when it warms up it idles from a low of 500 rpm’s to a high of 1500 and then repeats the cycle every 3 seconds. Any thoughts?

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**Author:** ![mikhail](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@mikhail](https://community.cartalk.com/u/mikhail)\
**Post date:** [March 3, 2010, 4:29pm UTC](https://community.cartalk.com/t/volvo-idles-erratically/5684/2 "2010-03-03T16:29:46Z")

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I have similar problem with my 1988 volvo 780 with 265k. The engine surges (not always) when it is cold and hot. It is fine on the highway. I have not done anything yet. Would be nice to know what causes it. I suspect throtle body switch or idle valve.