MrLexse

Lately, I've noticed a distinct odor (like a musty foot odor) in the interior of my 94 GTS. In the summer, when the windows are closed and the AC is on, is when it's most noticeable.
I haven't yet located the source of the odor, but it may have something to do with my losing antifreeze. I haven't seen any antifreeze dripping on the ground or dampness in the tailpipe, but every few days the "low coolant level" warning light goes on and I add some more antifreeze. Mats, carpeting and padding all pass the smell test. Any ideas where I should look?

Randy V

Just a guess, but pull the airbox and check if either of the hoses leading to/from the hot water valve are leaking. A slow leak would drip onto the rear of the hot engine and evaporate, resulting in no noticeable drips. These hoses are also in the direct vicinity of the fresh air intake for the cabin air.

Also, your '94 has a pollen filter on the cabin fresh air intake. Have you ever cleaned/replaced it?

urnotthesameina928

If the leak is small and slow its difficult. If the leak was from the heater coil I would have guessed a dampness in and around the mats. Maybe you can let the car run and heat up to operating temps and with a flashlight watch for any leaks. other areas may include plumbing or the plastic overflow tank itself. Over time the plastic becomes brittle and cracks develop. Your fresh air comes in by the windshield wipers underneath so you may want to clean up and watch this area at the rear of the engine. If that doesn't work maybe you need odor eaters

David.
81 Euro 5 speed
86.5 US Auto

docmirror

The coolant leak is clearly an issue, and may contribute or cause the smell, but it could also be a blocked AC evap pan drain. The AC evap unit will condense water vapor from the air, and the drian lets it run out on the ground. Start the car, run the AC and leave the car sit in one spot for a while. Look and see if a small puddle develops under the car, just right of center at the back of the firewall.

Coolant evaporating on the back of the car is also a source. I would make sure that is fixed either way. Follow the coolant lines from the engine back to the firewall, and locate any small dribbles. A radiator shop has a nice little air pump tool that will pressurize the system while the car is not running, which allows you to poke around with the engine off. Safer and more effective. may also be around the heater valve which is notorious for leaking.

Doc

928ntslow

FWIW, it has been known that some cars kept in a moist climate can develop a mold which is incubated in the evaporator. I have heard this of a few cars. Solution is to pull the dash and completely clean and disinfest the evaporator. Hope that this is not the case, but if all else fails....

Kaz

I just suffered a slow coolant link over the last few months that I simply could not track, could see no fluid on the ground and could occasionally smell when the car got hot. Finally the leak got worse and we tracked it to a plastic temp sensor thingy that sits next to the coolant bottle and tucked in under the passenger side fender. It had basically come completely apart. Since it's not a big hose even with it wide open it'd take 30 minutes to dump any appreciable amount of coolant.

If you're standing over the passenger side fender like you're about to fill the coolant bottle, look closer at the side of the bottle facing the front of the car and you'll see a two inch rubber hose that leads to this plastic thingamajig. It also has two wires plugged into it from the bottom and another hose on the other side. Take a look before you start pulling stuff apart. Part was 75 bucks from Porsche.

wds928

The thingamajig that Kaz is talking about on the GTS is the pressure switch. I just replaced mine two days ago which had a small leak, which was the replacement for one I replaced in April. Mine was just a small leak, but the smell was noticeable. Even after replacing the pressure switch, I still have a slight smell, so I believe a thorough cleaning with a pressure washer this weekend is in order to get rid of any residual antifreeze.

Jim M.

Also check your radiator plastic end caps. On my 89 the end cap was leaking, but it was slow enough and the radiator hot enough that I never saw water. It evaporated almost as fast as it leaked. I was also addding water on a daily basis.

Jim Mayzurk
93 GTS 5-Spd

cobalt

I was having a problem with my A/C. The fan would not blow as much air as it should and noticed that I was getting water spitting out of the center vents at fan speed 4, If I tuned off the A/C switch with the fan still running the volume of air eventually increased but I noticed a musty smell. rather unplesent. I ended up having a blockage were the condensation drains out of the system causing a puddle inside not allowing the water to exit quickly enough or the air to flow over the fins. This only occured on hot days when the A/C was working hard and build a lot of condensation in the system. The rest of the time there was not enough water to build up and create this smell. It may be worth checking to see if your system is flushing the condensation adequately.

MrLexse

Thanks all. I've got several good leads. The help you guys offer is underrated. I wish I had more technical expertise to "give back". Maybe in the future.