AC Compressor Clutch bearing Noise

Hi all, 2010 4.0 with 44,000 miles. Past few weeks I've heard a nasty rattle while idling in drive and at idle in park with the AC on. (AC works) Laying my head down by the skid plate it does sound towards the Compressor. I understand that when the vehicle is in drive at idle the vehicle is under load and that's when you will hear rattles from exhaust and such. More or less looking for someone to let me know if this is one of those tacoma things that has happened to anyone else. I know the video is not the best and cannot be heard too great because of my obnoxiously loud taco tick. At first it is in drive and then shift into park and sounds like it goes away then back to drive and it comes back. I posted the video to youtube anyway for all to listen and give their opinions.

https://www.youtube.com/watch?v=4MMKtrHWm9o

Thank you!

 

Sounds like a bearing of some sort but, yeah... hard to tell. I'm not super sure I would suspect the AC off the bat, did you have it on during this? An easy old school trick is to just take a broom handle, pipe, prybar, anything solid and long. Touch firmly on anything that's running on the belt, and just stick the other end on your head right below your temple and in front of your ear. Will literally ultrasound hear the insides from the vibrations though the solid broomhandle or what have you. Just be mindful and don't get caught in the belts and fan. I still diagnose (if fucking possible sometimes with these tiny cramped engine bays) which accessory has a bad bearing this way, quick dirty and simple as hell. Just again... there are belts and fans so pay attention, and the AC electric fans can and will turn on sometimes even when the key isn't even in the car.

Edit: oh I read the first sentence wrong, if all of it goes away with the AC off (and you're not set to defrost either), then yes I would start to suspect that bearing and clutch assembly. Fortunately if that is the case, you don't have to mess with the refrigerant and can just pull the bearing, pully, clutch assembly off and replace it.

 

Edit 2: upon listening again for the 14th time. Might want to check the belt and tensioner. I can hear some hiccup once the load of park and drive is applied and removed. That's a bit cheaper and easier and may be due anyways. With the engine off, and your hands clear of the fans, grab the belt and turn it, should only turn at most 90 degrees. Inspect the ribs of the belt for cracks. If there's cracks or you can turn the belt more then replace the belt. I may be lazy in this case and toss a new tensioner on becuase it's probably half on it's way out anyways. If the noise is still present then move on to accessories or the AC. The extra load may just be exacerbating a worn belt and or tensioner.

 

Take the belt off and run the engine, see if the noise goes away. Spin each pulley by hand and listen for growling

 

Appreciate it everyone

 

Popped down there with a stethoscope after work today and sure enough the tensioner pulley bearing is growling. Noticed the tensioner was bouncing but had good tension. Ordered an entire tensioner because although its only got 44k its 12 years old. Thanks for the input!

 

Just be aware you have to unbolt the A/C compressor and I believe the alternator to change it as it is part of the bracket that the compressor is mounted to, not a fun job but it is doable.

 

Yeah I've read... thankfully I'm a mechanic with access to a lift and a large tool arsenal so hopefully it won't be too bad lol. I only ask these questions to see if its one of those Tacoma quirks that is a pattern failure. Was mostly asking in the beginning if people saw failure in the clutch a lot but figured I'd just pull it in after work tonight since it cooled down lol.

 

@Dm93 did you or do you know if the coolant has to be drained? If so I figure i'll have an extra jug on hand.

 

Yea a lift makes working on things so much easier, I work in a shop as well and I can only recall doing one tensioner on a 2nd gen but we don't get many Tacomas in the shop.

I don't think so IIRC but like I said I've only done one and it's been a few years since.
I do know that for me at least taking the fan and the fan shroud out makes accessing the belt and pulleys much easier, 4 nuts, 2 bolts, some push pins, and it's out.

 

Ok, appreciate the help! I can do big time stuff on customer cars all day long but I get psyched up whenever I do my own stuff Maybe because its success depends on how I'm getting home

 

Yea so far mine has had no issues with anything as of yet (68k mi), I'm lucky enough my co-worker lives like 4 mi from me so I can hitch a ride if I need to.

 

I did the tensioner on mine. Major PITA. You can just unbolt the compressor no need to remove the Freon.