[buildadog]

Hi all. Last fall I purchased a 2011 Rav4 AWD 4 cylinder with about 120k miles. From the start I was having vibration issues. Was able to replace torque converter which solved my main problems related to grinding/vibration at around 35-45 mph, but I need help diagnosing another noise that is apparently unrelated.
There is a noise coming from the middle/passenger side of the vehicle that is noticeable only when in D and foot brake on and at a stop or very slow speeds. It doesn’t happen always; it can be loud or nonexistent. I describe it as a squeaky vibration noise. It doesn’t happen when the AC is on. Sometimes engine almost stalls too then regains idle. Can also feel vibration throughout vehicle

I replaced spark plugs. Didn’t help. Had mechanic check motor mounts. They say they are in good condition. Any other ideas? I’m stumped.

 

[Dr. Dyno]

Exhaust system loose?

 

[Foryota]

Hi @buildadog ; !

What is your idle rpm when in gear, under the conditions where you get the vibration? On the face of it, it sounds like your idle might be low for some reason. When you turn on the AC, the computer will run the idle higher to compensate for the additional draw on the engine.

 

[buildadog]

Hi @buildadog ; !

What is your idle rpm when in gear, under the conditions where you get the vibration? On the face of it, it sounds like your idle might be low for some reason. When you turn on the AC, the computer will run the idle higher to compensate for the additional draw on the engine.

Good question. Without he AC on, the idle is about 600. With AC on it fluctuates every 5-10 secs or so between about 600 and 1100 I’m guessing to run the compressor.

 

[buildadog]

Exhaust system loose?

Good idea. I’ll check into that.

 

[Foryota]

Good question. Without he AC on, the idle is about 600. With AC on it fluctuates every 5-10 secs or so between about 600 and 1100 I’m guessing to run the compressor.

600 seems low to me, but I’m unable to check mine for a couple of days as it’s on loan. I wonder if that’s part of the cause...

 

[buildadog]

600 seems low to me, but I’m unable to check mine for a couple of days as it’s on loan. I wonder if that’s part of the cause...

Yeah I’m going to check the mass airflow sensor and see if there is anything wrong there, but the vibration is definitely beyond just the low rpm. Something really seems to be loose

 

[Blogson]

Have you identified and solved the problem yet? Dr. Dyno suggests that the exhaust system might be loose - could be a heat shield as others have complained about the noise which you have and the noise has sometimes been reported as being caused by a loose heat shield.

 

[Bigphil555]

Just a thought. Do you have a small vacuum leak in the system somewhere - I think on MAF engines, low idle could cause a rough idle.

Are you able to look at any scan data at all to look in to fuel trims at idle a d say at 3500 rpm? I say this because on one of our cars, I had a dirty MAF (low readings from scan data) and a vacuum leak (high fuel trims at idle and normal at 3500rpm). Sorted these out and idle was back to normal.

Just some thoughts

 

[buildadog]

Have you identified and solved the problem yet? Dr. Dyno suggests that the exhaust system might be loose - could be a heat shield as others have complained about the noise which you have and the noise has sometimes been reported as being caused by a loose heat shield.

I think I’ve solved the issue. Cleaned MAS and throttle body and idle is now ~1000 rpm in gear. No vibration at all. Idles much more smoothly when AC is on. It used to jump between 600 and 1000 when compressor kicks in. Now it’s pretty much stable at 1100 rpm with AC on.

 

[Foryota]

I think I’ve solved the issue. Cleaned MAS and throttle body and idle is now ~1000 rpm in gear. No vibration at all. Idles much more smoothly when AC is on. It used to jump between 600 and 1000 when compressor kicks in. Now it’s pretty much stable at 1100 rpm with AC on.

Congratulations on steadying the idle! It does however seem quite high at the moment. Maybe that’s a separate issue now.

Have you disconnected the battery for a while to clear the idle memory? That used to work occasionally on my other vehicles when they got cantankerous... at least with the cleaned MAF and throttle body, your computer can learn the inputs again.


2012 RAV4 Base FWD.
Upgraded to large from brakes and 3rd row rear springs.

 

[Blogson]

I think I’ve solved the issue. Cleaned MAS and throttle body and idle is now ~1000 rpm in gear. No vibration at all. Idles much more smoothly when AC is on. It used to jump between 600 and 1000 when compressor kicks in. Now it’s pretty much stable at 1100 rpm with AC on.

Thanks for reporting back - hope that the problem has been resolved. Your solution is interesting.

 

[Bigphil555]

glad it looks like it is sorted