1993 camry v6 has the old refrigerant and no longer cools well. The garage says it is likely to be the compressor but I have read that the expansion valve can cause trouble. How do I find out which it is? To replace the valve apparently involves removing the whole dashboard at great expense.

SOURCE: How to I replace the oil filter on a 2009 Toyota Camry V6 engine?

Under the engine in the front you will see an aluminum cover.There is a square hole that fits a 3/8 ratchet remove this first.The new filter comes with a drain adapter that snaps in the hole under the cover.This lets the oil in the housing drain.Then take a oil filter cup wrench or a big channel lock to twist of the larger portion.Then change the filter and o-ring and reinstall.Make sure the o-ring on the square drive cover is there also

SOURCE: 1997 Camry Valve Cover Gasket Replacement

Removal of the plenum is pretty straight forward. You will need to replace the plenum gasket after you remove it; the gasket is not reusable. Personally, if I was going to take the trouble to remove the plenum, I would replace the plugs and wires back there, also.
I know, I have a 93 Camry V6, and it is a real pain to do the plugs and wires with the plenum on. There are no secrets or great tips on the plenum removal, just take your time. Remember that there are different size bolts, and where they go. Please get back to me if you need any more info...Hope this helps, and thanks for choosing FixYa to resolve your issue.
The graciousness of a FixYa rating for my assistance would be greatly appreciated.

SOURCE: 1993 camry v6 A/C Flashing

The AC light is flashing because the AC compressor "revolution sensor" is not working properly. You need to consider replacing the Revolution sensor that is located on the side of the compressor. You need a pro to do this, as the Freon will escape if you try this yourself.

SOURCE: 1993 Toyota Camry V6 Timing Settings

Get a T belt from toyota. It has 3 white lines on it and and arrow mark. 2 lines are solid and one is broken. Put the arrow facing away from the engine. The cam gears have a dot punched into them near a certain tooth. This is where the solid white lines will line up with. The crank gear will have a dot also. It will line up at 90 degrees from the top, towards the front of the car. This is where the broken line will match up with. With the belt installed with all lines on their proper dots and arrow away from the engine, you valve timming is correct.
Of course you need to remove and compress the tensioner also. I assume you know this already since you didn't ask.

SOURCE: I have a 1993 Toyota Camry V6. Problem : no

have someone get behine you and go from park to drive while they look, the switch may be out ov adjustment.also check the grond with a ling wire from the bat groung or grind a place ,,, check pigtails center with a test light.