Q: My dealer gave a quote of $2750 for replacing evaporator and expansion valve for my 2008 Lexus ES350. Does that look reasonable? c

The only reason to replace the evaporator would be if the evaporator were physically blocked internally or if it is leaking refrigerant. Be sure to obtain tangible proof of either circumstance. Verification is particularly important because evaporator leaks, except at the o-ring seals and that’s easy to fix, are just not common. As far as the possibility of internal blockages, if the air conditioning compressor suffers a mechanical failure, you can have debris everywhere in the system, including blocking the evaporator, but you have not indicated that you had a compressor failure. At any rate, first just be sure you get tangible (seen with your own eyes) proof that your car actually needs this repair.

As far as the economics of this repair, here is the basic data: The genuine OEM Lexus Evaporator Core (part number 88501-48311) vends for about $250 at on-line Lexus parts dealers, plus tax and shipping. The OEM Lexus Expansion Valve (part number 88515-33020) is about $75. You will need a new dryer to complete this repair (probably around $25-$40). You will need refrigerant, maybe $10-20 worth. So, parts come to $400 to $450 or so once you add shipping and tax. If you subtract $450 from $2,750, that difference, which amounts to $2,300, covers labor and shop "overhead". Labor time is 7 to 9 hours total on an evaporator replacement for your vehicle. Mechanics are highly intelligent but they are not brain surgeons so you should expect to pay not more than $90 an hour. Nine hours times $90 is $810. Now take, $2,300 and subtract $810 to get overhead and you have $1,490 for "costs" that indeed are NOT part or labor related. You’re probably wondering, and indeed this is one of the reasons that you wrote in, is it rational to pay $1,490 for shop overhead? Logically, though, you needn’t even wonder because you simply don’t have to pay it. If it turns out that you need an evaporator, you can avoid the shop overhead charge COMPLETELY by using a mobile service such as YourMechanic.

Regarding the expansion valve, inasmuch as that valve is difficult to "re-access" once a new evaporator is installed, due to its relatively low cost ($75), mechanics will go ahead and suggest replacement as sort of cheap insurance. That is, if you go to all the trouble and expense of replacing the evaporator and then later the valve fails, you’re looking at another new substantial repair job. Technically, though, if there is nothing presently wrong with the valve, then technically no you do NOT have to replace the valve. You can simply carry the old valve over to the new evaporator. If you want to consider having YourMechanic verify the issue simply request an a/c diagnostic and the responding certified mechanic will inspect what you have and give you a written quote. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.