2007 Sport V6 4WD. 225k miles. A/C went out over the winter. After 3 trips to local shop and 2 to dealer it's been determined that the evaporator is bad, which is what I feared the most. Expecting an estimate of $1200-ish I was shocked when the dealer quoted me nearly $3300. So, I've been dutifully reading the many threads regarding this in an attempt to tackle myself. I can wrench on my own rig (replaced the radiator at 110k) but haven't tackled something this extreme before, but I'm gonna give it a go.

The dealership had parts listed including a bolt, a couple o-rings, evaporator, expansion valve, and tube assembly. I'm also thinking just go ahead and do the drier and heater core as well while I'm in there.

Anyone have any additional words of wisdom or advice before I get started on this? Going to order parts and probably start in the next couple weeks, renting a car for a couple weeks just out of caution not knowing the pandora's box I'll be opening.

Thanks in advance!

I've done a swap of the old freon to the newer gas, but that's about all I've ever done. I have heard that if you open the system up you should always replace the drier. I see it's on your list so count on it.

Have you looked at the YouTube videos for doing this. I have found YouTube a good source for automotive repair information. Look at several. Don't just follow the first one you find. I would think that tools and gauges would be the biggest expense but if it saves you money and you never use the tool again, you're still ahead.

I was in your shoes last fall and tackled it. Not fun but not difficult, just time-consuming.

I replaced the condenser while the system was discharged, cheap and easy (comes with a new drier).

I also had replacement instrument glass on-hand (original was incredible scratched up) to swap and installed an aftermarket stereo at the same time which made running all the cables (USB/mic/etc) incredibly easy and made for a clean look.

Take your time, take pics and label everything with a system and you'll be fine.

I was also in your shoes last year. I did some research and the time and job was too much. Also my trusted mechanic only charged me $900 total.

master tech did mine for $200 labor and ran wires for amp hookup when back there. I got parts from RA for around $200, denso core, expansion valve but still kicking myself for not doing a heater core at the time.

So, just completed the evaporator core replacement, also did the expansion valve and condenser dryer at the same time. I was going to do the heater core but there was a delay in shipping, went ahead and got started on the job and found the heater core to look like nearly new, master Lexus tech I know (12 hours away) said not to bother replacing it since it looked so good.

Total time spent about 18 hours, completed by myself. I left the front seats in and only dropped, did not remove, the steering wheel. Left many of the wiring harness components attached to the main support bar and once unbolted it, just moved it out of place so I could remove the air box.

A couple youtube videos plus the page posted with 191 photos were clutch in completing this job. Lots of labelled items and baggies with identifying info. Was a bit easier than I had anticipated, but wouldn't want to do this again any time soon, mind you.

Take your time, be thorough, and be patient. This is not a very difficult job in truth, it's just a tedious one; it's just unbolting, unclipping, and wiggling things around.

I would have the refrigerant evacuated before you tackle the job, that's probably the biggest pain in the ass for someone doing the job at home; the second is just draining the coolant. Everything else is just a giant puzzle of panels, bolts, and wiring; which if you take your time and pay attention isn't as bad as you might think.

When I tackle dashboards and/or HVAC boxes among other interior work I like to do them roughly in this pattern as I find it the most efficient way for how I work:

-Start from one end of the vehicle and work your way to the other side; I'll usually start on the Driver's side and work towards the passenger side until I'm ready to pull the dash and then start again until I'm ready to pull the crash bar/HVAC unit.

-Set the hardware in the footwell (unless I am pulling the carpet, in which case I bag them and label them Driver's Side/Passenger's Side) on the side they go. i.e. "Left side for all the bolts, clips, and hardware driver's side of the center console, right footwell for the right side."

-I also like to stack parts in the back seat if possible opposite of the side I am sitting, for example if I am working on the left side of the dash I will set all the trim panels, covers, etc. on the right rear passenger side and I'll scoot the center console into the middle of the rear seat. The reason for this is so that as I am reassembling the vehicle I just reach over behind me and grab parts; you can also set them outside of the vehicle on the corresponding sides to make things easy to remember.

-Make a note of the types of bolts used as you take the vehicle apart, you'll notice things like some bolts have different sized washers which can make it easier to tell whether a bolt was used to hold a trim panel on or screw in the radio assembly for example. If you pay attention and make a small effort to mentally note things, you'll start to see the pattern of how things are attached/secured and reassembly makes more sense.

-A couple good trim tools are money well invested, a pocket screwdriver or even a regular flat head works in a pinch; but good quality plastic/polymer trim tools are the least likely way you'll damage your interior.

-A lot of the panels will be clipped together, even after you unbolt them; they can be hard to pop off; don't be afraid to apply additional consistent pressure and work it off; good rule of thumb, creaking isn't much to worry about, cracking means you should stop and revaluate what you're doing and see if you can find a better way to do it.

-A second person for pulling the dash and wiggling the crash bar is a very nice thing to have, but if you have to do it yourself, plan out your movements and what you want to do; it's much easier to figure it out before hand, than when you have the dash or crash bar in your hand.

-You're not flat rate, so there's no reason to rush this; take your time and do it right, if it takes all day or a couple days, that's fine as long as it's done right. Plan to have the vehicle out of commission for at least a week (not saying it will take you a week, you should be able to get it done in 1-2 work days, i.e. 8-16hrs even going slowly), that way if there are any unforeseen surprises or life gets in the way, you're not pressured to rush the job.

-You don't have to pull the crash bar out, you can unbolt the HVAC unit from the crash bar and tilt the crash bar up and outward enough to wiggle the HVAC unit out; it's a pain to do yourself and a little easier to do with a second person, but it is doable. That being said, if you have the time and patience, the easiest thing to do is just pull the crash bar out completely.

That's everything I can think of off the top of my head for the moment... Oh! Make sure to cap off the Heater Core and/or try to siphon/suck out as much coolant as possible, it will dribble out the pipes when you pull the HVAC core out (even if you think it's fully drained).