# Rough idling, Ford Fusion with turbo

**URL:** <https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914>\
**Category:** Factual Questions\
**Created:** [November 18, 2020, 8:56pm UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914 "2020-11-18T20:56:14Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\
**Post date:** [November 18, 2020, 8:56pm UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/1 "2020-11-18T20:56:14Z")

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I have a 2016 Ford Fusion with turbocharger. It has 75000 miles on it.  
It is idling rough. Occasionally it almost dies, then recovers and idles OK for a while.  
When under load, it seems to run well. No hesitation that I can detect.  
I understand that the valves might be fouled. It has direct injection, not injection outside the cylinder.  
I am concerned about what I have heard about cleaning the valves. As I understand it, some valve cleaning solutions raises the temperature of the exhaust high enough that the turbo can be damaged.

Does anyone know how best to safely fix the rough idle problem on these kinds of engines?

Thanks in advance

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**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\
**Post date:** [November 19, 2020, 3:05am UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/2 "2020-11-19T03:05:31Z")

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The first thing I’d do is check carefully for any kind engine vacuum or air intake leak.

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**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\
**Post date:** [November 19, 2020, 4:02am UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/3 "2020-11-19T04:02:00Z")

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thanks. When I have the car checked, I will keep that in mind. My mechanic is careful, not cheap but I will take that trade, and won’t do anything he can’t prove. Unlike my local dealer. The more parts they can through at a problem the better they like it…

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**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\
**Post date:** [November 19, 2020, 6:05pm UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/4 "2020-11-19T18:05:22Z")

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**Gary\_T** is correct as usual. Vacuum leak is the #1 probability followed by spark plugs, followed by ignition coil. At least according to this site:

[Ford Fusion Rough Idle](https://repairpal.com/ford/fusion/rough-idle#:~:text=While%20there%20are%20a%20variety,problem%20with%20the%20ignition%20coil).

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**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\
**Post date:** [November 19, 2020, 7:01pm UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/5 "2020-11-19T19:01:12Z")

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excellent!  
thanks for all your help.  
I know what to expect when I take the car in to the shop.

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**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\
**Post date:** [November 19, 2020, 10:27pm UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/6 "2020-11-19T22:27:51Z")

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I saw a trick for checking vacuum leaks on _Roadkill_. Using ether starting spray, with the engine idling, spray around the throttle body and attached hoses. If the engine speeds up, you’ve found a vacuum leak.

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**Author:** ![Polarity](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@Polarity](https://boards.straightdope.com/u/Polarity)\
**Post date:** [November 20, 2020, 3:19pm UTC](https://boards.straightdope.com/t/rough-idling-ford-fusion-with-turbo/925914/7 "2020-11-20T15:19:16Z")

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Just have to be careful spraying that stuff around any hot exhaust pipes etc.
