My 05 toyota rav4 S with 105k miles on it has a winding sound coming from the engine, wondering if anyone knows what could it be? i'm suspecting the belt tensioner bearing or the alternator bearing... please help . the sounds starts the moment you start the motor and it kinda sounds like engine noise on a sound system, it goes with the revolution of the motor it goes high and low

Mike Butler

• 6674 Answers
• Posted on Dec 30, 2008

SOURCE: squealing engine

My guess without hearing it, is that you have a loose or worn belt causing the screeching, or squeeling noise your hearing, but as far as sluggish goes, that may be another thing all together. I'd suggest having your belts looked at and adjusted or replaced as necessary. Once it's confirmed or not that your noise was from that or maybe even a tensioner, then we can go from there. In the meantime, chek your oil level just as a precaution, if you haven't lately, and top it up as needed. They are usually a pretty reliable car, so I wouldn't hit the panic button on it being an engine problem yet.

SOURCE: belt tensioner leakage?

In my 37 years of working on cars, I never, ever heard of a belt tensioner leaking, All there is inside is a heavy duty spring, and after awhile they become weak, causing the belt to squeel. There is no adjustment on them, just replacement.

SOURCE: Toyota Highlander with loud humming noise

2002 Hylander 4cyl.
all power windows work from the driver's arm rest control however,
all of the other arm rest power window controls do not work separately
on their own.
checked all the fuses and they are ok.

SOURCE: I had 2003 Toyota Camry 4 cylinder in for

While it is a possibility, having the tensioner lose tension seems more probable that it locking up as the mechanics have stated. You seem to know what you are talking about, so why not try throwing a wrench on it and turning it towards the serpentine belt? Then you can see for yourself if it has seized or not. It is the small pulley that doesn't seem to power anything like your AC compressor, alternator, fan, crank, powr streering. match a wrench to the size of the bolt and turn it, if it moves take the belt off (noting how it goes) and put the new one on saving you 280 dollars.