Hi Guys,

Over a couple of years, i've experienced the dreadful vinegar smell coming out from the vents and like most of those who experienced this problem, it was due to a rotten evaporator core.

A year ago I decided to change the core but opted for a cheap 3rd party core. While the smell went away completely, the AC never cooled to its potential as it used to be.

Unfortunately, a month or so ago, the nasty smell started again! Not as strong as before but it's definitely there. Currently, I have the below issues:

- Once the car starts, it takes around 3-4 minutes for the AC to properly cool. It only blows cold air if the fan is set at very low speeds. At high fan speeds, i would say the cooling decreases by 40%. This only started happening after i changed the evaporator core.

- During hot summers. it' impossible for the AC to cool at all, I can't use the car in summer unless I am parked under a shaded area. Even then, i can only turn on the AC at a low fan speed for cool air to blow. Forget about using high fan speeds in summer, it just wont cool.

- The smell started again, which is quite disappointing, i cannot believe the core is damaged again unless the previous mechanic did a poor job at fixing the new core.

Based on what i've seen in the forums, the issue is due to the expansion/control valves?

Anyway, i decided to take it to the official dealer and asked them to check if the issue was related to the expansion/control valves and after they tested the AC pressure and refrigerant levels, they were more or less the same since a year ago when i replaced the evap core. They also said that there are no issues with these valves.

I don't know what to do now, the dealer doesn't know what's the issue and they didnt want to change these valves. There can't be any AC leaks since the refrigerant levels would have lowered over time and the AC does cool but it takes quite a while to do so and only at low fan levels. Is it because of the cheap 3rd party core? It was such a hassle removing the whole cabin, I shouldn't have cheap out on the core but wanted to save some money.

Any help would be greatly appreciated!

 

Hi Guys, anyone facing the same issue? Any help will be greatly appreciated.

 

I'm not sure about associating the smell to the evaporator's performance and ability to cool. If your system was correctly vaccuumed and the correct amount of R134 + oil was added your system should be chilling properly. Have you put a gauge on it to see if it has the correct charge?

The smell is most likely due to something in the air duct or on the evaporator fins or general area - possibly mildew caused by the condensation not properly draining out leaving some water to grow a science project around the evaporator. clogged drains is also a reason why the evaporator failed in the first place - it probably rotted from the outside in. Have you looked into products that sanitize the air ducts (like Frigi Fresh) - you can also try misting a white vinegar or mild bleach solution into the cabin air filter air intake etc. Finally see if you can get the evaporator drain ports cleaned out. Dunno about the S80s but this is a common issue for 850s

 

Thanks for your reply, I took it to the dealership to check the pressure and it was perfectly fine.

The smell is not directly associated to the ability to cool, it was just related to the previous issue I had before replacing it, my concern was that the cooling is not strong enough maybe because it was a 3rd party Chinese replacement?

About proper vacuuming and cleanup after changing the core I am not sure, the mechanic who performed the job told me he cleaned everything as per procedure but then why did the smell returned? I have used similar solutions to Frigi and they work for a while but then the smell returns.

 

a properly trained tech will put a vaccuum on the system during the recharge - its the DIY shade tree mechanics who don't have the tools to do so.

My hunch is the smell returned because the condensation from the evaporator isn't draining out properly or you have a blockage in the airway. Have you checked the cabin air filter recently? LOL i had to use my shop vac on my wife's car after a mouse or chipmunk decided the cabin filter was a great way to build a nest. We only knew it when some acorns hit the blower fan.

 

Now that I remember, the cabin filter was just "cleaned" using an air hose haha. I didn't worry about it that much since then. I will check it out this weekend.

I'll check for clogs then since the evaporator is indeed new but a cheap replacement.

 

Hello Boss,
Do you have short procedure on how to replace XC90 evaporator?
TIA
Ron