AJAA

I have a Toyota mechanic who works on my car after hours. My 2012 RX 350 has 96K miles on it and he recommended replacing the drive belt and PCV valve. I don’t see these items on the Lexus maintenance schedule, so I wouldn’t have even known to have them checked. Is the drive belt a different belt from the lifetime interference timing chain? How often should it be replaced? How often should a PCV valve and spark plugs be replaced? Where can I find replacement timelines for items.

RX in NC

Your mechanic is referring to your serpentine belt that drives the alternator, water pump, compressor, etc. Usually a good idea to replace that belt around 100,000 miles on ANY vehicle, not just a Lexus. Your PCV valve may be fine. Typically if you remove them and they rattle when you shake them, they are fine.

Hayk

iTrader: (1)

Drive belt is also known as the Serpentine Belt, right around the 100k miles is a good time to replace it. The grooves on modern belts wear down like a tire tread, so it may not be obvious that it needs replacement. They don't easily crack like the old style materials so it's harder to inspect. The belt is what moves your A/C compressor, power steering pump, and alternator.

The PCV valve is screwed into one of the valve covers and helps control the flow of Positive Crankcase Ventilation (PCV) gases. If it gets clogged and stops working you will end up with too much pressure in the engine and oil seals will start to blow out to relieve that pressure - not good. 96k is a good internal to change it out. I replace mine every few years on a 98 ES300 as they're pretty cheap and easy to access.

AJAA

I have to take my car back to him again today the AC was blowing warm air and he recharged it w refrigerant but it still vacillates between blowing cold air and warm. He said we’ll have to look at the evaporator and expansion valve.

Clutchless

Your A/C issue may be caused by loss of magnetism on the sensor switch. See this thread after post 88 to learn how to fix it by placing a small magnet on the sensor. It can save you from buying a new compressor! https://www.clublexus.com/forums/rx-...olution-6.html

RX in NC

^^ What he said....

salimshah

A thin manual in your glove compartment covers warranty and maintenance. It has the milage/time based service items listed. If you have been taking the vehicle to a dealership, they don't make entries in there. Since I do mine, I record them there. There is a online portal too.

Salim

AJAA

Is this sensor reached by putting the car on a lift?

Clutchless

Jack stands may lift it up enough for this job.

From what was posted elsewhere: You cannot access the sensor from the top, only through the splash guard. It is a little tight in there. Read more of recent posts in the link above.
I have not done this myself, but there is a splash guard under the front of the engine. It has a lot of 10mm bolts. An electric screwdriver with a 10mm socket makes it a lot easier to remove. Plus it has some plastic push pins.

It may help to open the hood, remove plastic stuff covering the engine on the passenger side to view the A/C compressor, which is on the passenger side as it is fed by the serpentine belt, and then hopefully, you can locate the switch. Study the photos in the threads linked above to learn what to look for and where the magnet goes. Or just show the photos to your mechanic. He will know.
Now if you need help removing the plastic pins that hold the plastic covers on.... you push them down in the center to remove them. To replace them you have to push that pin back up so the top cap above the sides. Then wiggle the legs back into the holes and push the top cap back down so it is flush with the sides of the pin. Have fun.