2006 Rav4 Sport V6 makes intermittent low rumbling noise

At around 85k miles, I noticed a low rumbling noise around 1600 RPM. The noise is most noticeable around 40 mph, comes and goes only when the accelerator is depressed. Our local shop said I need to replace the entire automatic transmission. However, I took it to a trusted Toyota-only independent shop and the mechanic drove around with me and immediately identified the noise as the torque converter. He says the noise is annoying, but unnecessary to remedy. He changed the transmission fluid and I’ve been driving with the noise since then, now around 90k miles.

Has anyone driven with this symptom for a long time? He told me he has pushed one with this noise to over 150k miles. I see this issue has been seen before, 2006 Rav4 "rumbling" noise and 2007 Rav4 rumbling

All wheel drive?

Toyota service bulletin TC006-07 is for a drone noise and vibration at highway speeds. The repair involves replacing the 4WD computer.

Here is the bulletin;

http://www.rav4world.com/tsb/2007/TC006-07.pdf

Thanks for the bulletin. It is AWD, but the noise occurs in any gear around the same RPM range. It is most noticeable around 40 mph on level ground. I gather that I would have to pay for the 4WD computer swap since I’m past the 60k miles.

You should change the fluid at frequent intervals, perhaps every 30k.

I’m not sure the bulletin applies to your problem but with two others reported here it seems to be common.

Toyota computers are very expensive, this one has a MSRP of $860. If you search the part number in the bulletin, 89630-42020, you can find new and used listings. There is a used one on Ebay for $80.