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Toyota Camry 2007-2011: Why is My Car Idling Rough?

The Toyota Camry is well regarded for its overall dependability and longevity, but without proper maintenance, it can run poorly and idle with a vibration that can loosen tooth fillings. If you are already experiencing this low idle shaking, don't worry. Simply read on.

By Keith MacDonald - August 4, 2015

This article applies to the 6th generation Toyota Camry (2007-2011).

Sometimes, even the most avid DIY car care fanatics can miss an important maintenance item, which may cause a poorly running engine and decreased fuel economy. Sure you can change your oil and filter, replace your air cleaner, and flush your radiator and transmission, but if you skip on cleaning the intake tube and throttle body, you're eventually going to have a case of the engine shakes. Combined with low idle RPMs, you'll become very concerned about your Camry—and perhaps a little guilty, too! Let's discuss a few easy preventative tasks that'll keep that dependable Camry dependable!

Materials Needed

  • Carb and choke cleaner (make sure it's safe for plastics!)
  • Shop rags or paper towels
  • Flat head screwdriver
  • 10mm socket and 1/2" drive ratchet
  • Air cleaner (look up the correct replacement wherever you buy auto parts)
  • Rubber gloves (to keep that carb cleaner away from your skin)
  • Shop vac or hand-held vacuum cleaner

Step 1 – Reset the electronic idle

Before diving into your Camry's intake system, try this simple reset:

  • Disconnect the battery and wait five minutes before reconnecting it. This will reset your ignition and should bring everything back to their default positions.

If your car still has a rough idle, move on to the next step.

Step 2 – Check the air filter

The intake system and air filter are the only means for air to enter the engine. So if the air filter is dirty, the engine may choke up, causing a small, rough idle. If you find a dirty air filter, purchase a new one at any parts store.

  • Remove the front and rear 10mm bolts on the air box.
  • Lift the air box cover from its right side; there are hinges on the left side of the cover.

Figure 1. Loosen the air box cover.

  • Pull out the old air filter with your hands.
  • Insert new air filter, and make sure that the only squared corner of the filter goes into the far left corner.
  • Re-install the cover and secure it with the bolts.

Figure 2. Match up air filter's square corner to the housing.

Pro Tip

Get out your shop vac or a small hand-held vacuum cleaner to clean out the bottom of the air filter's housing, which is where heavier dirt and leaves may have accumulated.

If your car is still idling a bit rough, move on to the following step.

Featured Video: How to Replace Air Filter

Step 3 – Clean intake system and throttle body flap

A dirty air cleaner, intake hose, and carbon-crusted throttle body can all choke off your air intake, causing lowered RPMs at idle, decreased power, and loss of fuel economy. To relieve the problem, let's clean these parts out!

  • Remove the air box cover and the throttle body intake hose.
  • Place a shop rag or paper towel under the throttle body.
  • Spray the butterfly as well as casing with carb cleaner to remove carbon and dirt.
  • Hold the throttle plate closed, have someone turn the ignition switch to "on," and quickly release the throttle plate.
  • Clean or replace the air filter.
  • Clean out the intake hose between the air filter and the throttle body.
  • After cleaning, you'll need to reboot your on-board computer's idle control by removing the ETCS and EFI fuses.
  • Wait five minutes, and then put the fuses back in.
  • Re-install the intake hose and air filter housing.
  • Allow engine to idle for a few minutes.
  • Figure 3. Carbon scoring around the intake butterfly or "flap."
  • Figure 4. Spray carb and choke cleaner into the throttle body to loosen the grime as well as carbon buildup

Pro Tips

  • A fresh air cleaner will really help your cause!
  • Use only an intake air cleaner spray that is labeled as "safe for plastics."
  • Allowing your engine to idle for a few minutes after cleaning the throttle body will not only burn-off any leftover cleaning solution, but will also allow your on-board fuel intake sensors to reset themselves.
  • If the engine still idles slow and rough, take it for a short drive around the neighborhood to help the air intake sensor "re-learn" its settings.

Why is My Car Idling Rough?

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