Vibration at Idle in Drive - Worse Under Load

#1
Hello all! I'm experiencing a vibration with my 2015 Toyota Corolla LE (1.8L, CVT) that appears to only happen while stopped and in Drive. At a stop light for instance, sitting idle, a vibration can be felt through the car. It also gets worse when an additional electrical load is placed on the car, most notably rolling a window up/down. The vibration is normally pretty continuous when it does occur, but it doesn't happen every time I come to an idle and also almost seems to pulsate at times. Some days it happens more than others. The vibration goes away once I start to accelerate and does not occur in Neutral or Park. It also almost seems like the vibration is worse on colder days than warmer days, but I'm not sure if this is fact.

I'm also not sure if this is related, but after having the car in the garage for a few days (undriven), starting the car resulted in a really rough start. It shook and didn't seem like it was going to turn on for a moment. It did start, however, and it was fine afterwards. I haven't had that issue since then.

Any thoughts on what this might be or where I should start for diagnosing it? The car only has 51,000 miles on it. Thanks in advance!
 
#2
So I drove around a bit just to fine-tune my description of the issues I'm seeing. When the car is cold, there is no noticeable vibration as the the engine is idling at a higher RPM. However, when the car is warmed up, the engine RPM drops to around 600 RPM at idle in Drive. While warmed up, at idle, in Drive but with no major electronics turned on, there is only a minor vibration to no vibration. Now, in the same conditions (warmed up, at idle, and in Drive), applying any large electrical load (i.e. rolling up the windows, turning on the AC, turning and holding the steering wheel while stopped) a noticeable vibration is developed. The easiest way to duplicate it every time is, while the windows are rolled up, hold any of the window up buttons; this causes the vibration every time. This happens only in Drive and Reverse. Park and Neutral do not have any vibration when applying any of the above electrical loads.

In summary, there is a vibration that occurs when applying an electrical load when the car is warmed up, at idle, and in Drive/Reverse. Any ideas what this could be?
 
#4
Test the battery and the alternator. A defective battery can have an adverse affect on an alternator, and vice versa.
Thanks! So I've been taking some voltage readings with my multimeter.

This morning, with the car off, the battery voltage was 12.6 V. That seems normal.

Now, turning the car on at idle I'm seeing 13.9 V. Revving the engine to around 2000 RPM I'm seeing 13.99 V. Depending on the website, I'm seeing normal is 14.2 V to 14.7 V. Other places are saying 13.5 to 14.5 V is nominal.

Shutting the car off, the voltage is higher than 12.6V, which means the alternator is charging the battery.

Any thoughts on this?
 
#5
Thanks! So I've been taking some voltage readings with my multimeter.

This morning, with the car off, the battery voltage was 12.6 V. That seems normal.

Now, turning the car on at idle I'm seeing 13.9 V. Revving the engine to around 2000 RPM I'm seeing 13.99 V. Depending on the website, I'm seeing normal is 14.2 V to 14.7 V. Other places are saying 13.5 to 14.5 V is nominal.

Shutting the car off, the voltage is higher than 12.6V, which means the alternator is charging the battery.

Any thoughts on this?
Also, at idle with headlights and brights on, radio on, and heater on, the voltage reading is 13.7-13.8 V.
 
#6
Those figures look fine. Did you test the regulator portion of the alternator? If not, connect the meter leads to the battery and put your meter setting to AC volts. Rev the engine to ~1000-2000 rpm. You should see 0 volts. Any voltage reading indicates a diode failure. If this is okay, my suggestion would be to have the battery and charging system load tested at an Autozone, NAPA, or other auto parts store which offers free testing.

I should add that you need to turn on your vehicles accessories (ac, radio, lights, etc.) to load the electrical system down.
 
#7
It might have to do with a dirty air filter, try replacing that.

If that doesn't work, clean your airflow sensor. Do a search for "Scott Kilmer - Airflow sensor" on youtube. Do a search for what an airflow sensor does cuz my fingers are cramping up from pecking at this phone.

Airflow sensors cause issues eventually due to carbon buildup and crud. The sensor is a part of an assembly that operates a butterfly flap. It determines the right amount of air to mix with your fuel. When it goes out of adjustment, it does what you are describing.

Don't forget to clean the butterfly flap. It must rotate freely. Like i said, carbon buildup can also occur along the walls of the throat the flap resides in causing friction. The rotating part can also get dirty. Use carb cleaner or air flow sensor cleaner to liquify the carbon and the crud. More than likely this is what caused your hard starting.

I have a 2005 Pontiac Vibe, and doing this makes it run like new even at 195K.

Jose
 
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