Very strange but i hear a grinding sound from the backend when going uphill at 40 mho. This is the only time it occurs and it only lasts about 3 seconds. Have my mechanic baffled as well, any thoughts?
By chance, would this be on the 2.4 liter I4, cruising at lower RPMs, on level ground or uphill, a grinding-resonating sound of "WRAWRAWRA?"
I had a mechanic check into mine when it displayed the above behaviour. They first faulted the exhaust (which was forming a legitimate leak). After replacing it, the behaviour still continued. When I was able to reproduce it, he diagnosed worn rubber braces for the exhaust, which were supposedly allowing the exhaust to resonate. When his colleague inspected the exhaust, however, he re-welded some of the previous exhaust work. Once I left, the noise crept up again.
TLDR; does anyone know anything about rubber braces for the exhaust?
Have heard the same noise with our 2010 RAV4. Toyota checked it out and said no problem - normal. Then, we just got "Warranty Enhancement Notification ZF4" - says "vehicle may exhibit a growl type noise from the rear differential coupling when driving due to contamination of the front bearing." It's not clear what they might do to fix the condition but it does say you are due "reimbursement consideration" if you've had previous work done. Good Luck!