slicky rick

Our car are reaching the age that the evaporator might be getting dirty. Brothers complaining of musty smell, weak air flow, generally lower ac performance. Has anybody gone through ac evaporator cleaning? What work is involved? Has anyone tried out those evaporator cleaning chemicals you just spray into the evap? For discussion.

user 72902

I'm prepping to replace my coolant with Evan Waterless and will be replacing my three from radiators. Funny you mention this because I was thinking the same thing about the AC condensers. I have a tool to straighten out the fins and will clean while my front nose is off. I was thinking since the condensers are in front of the radiators and take the most abuse from flying objects how many of us have slow leaks and hence less efficient AC systems.

slicky rick

Exactly jw, our cars are of the age already that there are some issues that need to be addressed.

Bruce In Philly

Cleaning these radiators are a fairly agreed to necessity.... but I am not so sure. I cleaned the radiators after 194K miles (all year driver)...... if doing this was a priority, they would be shot by then. I posted some pictures in this thread here:

https://rennlist.com/forums/997-foru...diators-2.html

Peace
Bruce in Philly

Spiffyjiff

why cant you all just do it the easy way like i did - put the front end into a track tire wall, and get them replaced with new ones "for free".

wwest

Have you checked/replaced the "pollen" filter?

Could cause the weak airflow problem....

The filter makes it practically impossible for the evaporator to clog up seriously but musty odor is yet another issue. Buy a new filter, soak it with Lysol spray and now run the fan/blower at high speed in fresh air intake mode with the A/C OFF for 10-15 minutes.

Use a high temperature (full remix) setting so the Lysol also "cleans" the downstream heater core.

slicky rick

Hi west, i think i wrote somewhere, in tropical countries where heat and pollution are issues, seldom does the recirculation button not get activated. Drive around a minute in traffic and you smell smoke and exhaust in the car is the recirc button is left open. It is unfortunate though that again porsche left out an in cabin filter that almost all foreign cars have since the late 1990's. I have a 2010 mitsubishi suv and you should see the dust that the evap cabin filter has collected. Its increible porsches do not have it...well the 991's now do have it.

mdrums

At least you have more fun than they did..

Seeeu911

What are you talking about ? Cabin filter is present on my 99 and 03

wwest

I think OP might mean that the filter is not in the recirculate "loop"....

Not sure it needs to be.

slicky rick

West is right. Its a filter in the recirculate loop. Not saying its needed in US, but i surely need it. Why do you think its now standard on the 991? It prevents a very costly maintenance procedure. Cleaning the evap, might need a full dashboard removal, i dont know for sure but, i just thought someone has gone through it and knows how its done. Im just thinking its bloody. An in cabin filter, replaced every so often would have prevented this maintenance procedure.

GSIRM3

What is the costly maintenance procedure that a filter in the recirculation loop prevents? Most people don't leave their AC in recirc mode all the time, and in fact it is not recommended.

slicky rick

Hi gs like i mentioned. Maybe its not recommended in the us, i do not know, but it does not mean its not recommended the world over. In hot tropical contries the where temp is normally at 30 to 36c the whole year round, what do you do? Where 3 munutes into you driving and your in traffic with a diesel bus in front of you, what do you do?
My mb s class turns off recirc mode in 30 minutes, once it opens, i immedieately smell exhaust fumes so i close it again...its an old model yet it has an in cabin filter, heck it even has an in cabin charcoal filter.
What maintenance is prevented, well all inlet points to the evap, wheter looped or from the outside is filtered minimising the possibility of getting the evap dirty. Cleaning the evap is a bloody procedure cause i think it needs dash removal.
Like i said porsche finally realized the need to put the in cabin recirc filter by making it standard on the 991.

Macster

For the smell try replacing the cabin air filter.

Hard to imagine a cabin air filter so dirty it cuts down on air flow, but you'll know it was (or was not) after the filter change to address the smell.

If the smell remains this can be due to mold/mildew on the evaporator. Iv'e never had this problem with any of my cars so I have never had to address it. I have read in some models the evaporator can be seen and accessed to some extent from above and inside the front trunk, after removing the battery cover and other panels, oh and the cabin air filter and whatever hardware around that one can remove. I have not confirmed this. It may be possible to access it from underneath, too. By access I mean spray some cleaner on it and let it soak then rinse the cleaner away along with any mold/mildew that the cleaner might have loosened.

Whenever I use my car's A/C I shut off the compressor a few minutes before reaching my destination and let the fan continue to run to dry the evaporator so mold/mildew is less likely. So far I have been successful, for the few times things got musty smelling a cabin air filter made it all better smelling again.

If the A/C is not as efficient and a new cabin air filter doesn't help it could be the system is low in refrigerant.

There is a test that involves running the engine at something above idle, turning the A/C to max cool and measuring the ambient and vent temperatures and confirming the vent temperature is within an acceptable range. I do not have the numbers for the newer models.

But if the test fails then the A/C probably needs some professional attention.

Be sure the radiator ducts are clear of any trash. While the engine cooling system and A/C have enough margin that just one side will suffice there is the concern about corrosion.

Last but not least be sure both radiator fans come on when the engine gets hot enough and both come on when the A/C is switched on. On both my Boxstesr and my Turbo I have had a radiator fan quit. In the Boxster it was a ballast resister.

In the Turbo there were two fan failures. The first time it was the passenger side fan. The fan motor shaft snapped in two.

The second time it was the driver side fan. It didn't completely stop but it was clearly not moving nearly as much air as the other side. There were no fan stage errors but the tech found the fan was using a lot more current so at my direction he replaced the fan motor and the new fan blew windstorm of air that matched the other side's output.

Might mention in both cases of the fan not working neither car exhibited any signs of overheating and the A/C worked just fine. In the first fan failure of the Turbo I discovered the fan not working in Fresno in around 95F heat. Yet the A/C had kept, and continued to keep, the cabin at 72F all the way down there and back home through 90F+ temperature.

Bruce In Philly

Could someone describe "evaporator".... I am a bit confused. As I understand it, we have the A/C "condenser" panels in front of the radiators, and a Heat exchanger just behind the battery. What else is there?

When i did a word search for "evaporator" in the PET diagrams, it came up once and points to the plastic compartment/cowling that holds the heat exchanger (Part 997 573 901 02).

If this is what you are referring to as the evaporator, I had smell in my car that a few felt was mold... it actually was a tiny leak in the heat exchanger. I pulled it and it had a tiny leak. Very easy to replace... I used a Pelican OEM part.... much cheaper and was litterly, IMO, the exact same part.

Peace
Bruce in Philly