Rough Idle

2006 DODGE STRATUS
112,000 MILES • 4 CYL • FWD • AUTOMATIC
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BREEZER4
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I have a 2006 Dodge Stratus, 4cyl which has always had a rough idle but has worsened over time. Steering wheel vibrating quite noticeably at a stop light while in forward gear. Minimal in reverse, park or neutral and nearly nothing if revved up to 1200 rpm in neutral. Not noticeable while driving down the roadways at all.

Oil/filter change(s), timing belt change, tune up, and leaking exhaust resonator all done within the past 12k. Normal rpm is set at about 700-800 rpm.
Feb 10, 2011 at 12:36 AM
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KASEKENNY
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This is almost surely a vacuum leak.

I have seen this a number of times on this engine and the intake manifold leaks and allows unmetered air into the engine and the PCM is able to adjust enough to keep it running.

However, it is a rough idle due to the imbalanced ratio.

So, we need to start with the guide that will help to confirm if this is the issue:

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

Next, we need to monitor the o2 sensor data and find out if this is lean.

If it is, then we need to confirm there is no intake valve leaking by using a vacuum gauge on the engine and see what the needle looks like.

I am attaching charts below that will help with this.

Let me know what questions you have and what you find.

Thanks
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Apr 16, 2022 at 5:34 PM