justim

Hey Everyone,

I think I have my problem nailed down but I figured I'd get a second opinion while I wait for parts to get delivered... just in case there's something else I can try.

This past weekend has been a rough couple of days for my 2000 GS300. It all started with a simple squeak that appeared to be coming from the tension arm. From there my A/C failed, power steering cuts out occasionally and now my alternator is failing under 2.5k RPM. All signs point to serpentine belt or tensioner.

My suspicion was the tension arm is weak but I replaced the belt anyways. This didn't help at all.

If I put the breaker bar on the tension arm pulley and pull the belt tighter everything springs back to life. A/C is cold. Power steering is smooth. Alternator is charging. This makes me think the tension arm is weak.

The car has 295,000 km and as far as I can tell the arm has never been replaced. Is this a common problem after 15 years? Could the culprit be a seized alternator or powering steering pump? (water pump is 20,000 km old so I'm ruling that out and problem is happening with the compressor turned off)

salimshah

Tensioner has marking which shows good range.

Salim

natman

Remove the belt and see if the individual devices turn smoothly. Also check the tensioner pulley to make sure it turns smoothly. If it doesn't turn smoothly, or it turns with no resistance at all, the bearing needs some grease.

It should require some effort on a long bar (like a 1/2" ratchet with a cheater bar) to get the tensioner to move out of the way. It sounds like there's not enough tension being applied and the belt is slipping. Was the inside of the old belt glazed?

justim

Turns out the root cause of the problem is a bad alternator. It just happens that my tension arm is on it's way out at the same time but isn't the cause of the belt slipping.

justim

Just updating this thread incase someone searches for the same problem:


Turns out my problem wasnt the alternator after all. My problems came back after a new alternator and new tension arm. I took the car to the dealership and they found that the harmonic balancer was snapped and shredded. I guess that explains why every accessory was failing. Parts and labour is $844 Canadian. I can find an OEM part cheaper online but after 3 weeks of not driving I'm itching to get it done and get behind the wheel again.