I smell a rat!
 

I recently reawakened my '08 Box S after a year of slumber while I was working abroad. After a bunch of maintenance, including air and cabin filters, brakes, oil, and a MAF/throttle cleaning, she runs great.

I should also note that I dropped a plastic-handled screwdriver thru the engine compartment when cleaning the maf. I heard it fall onto the aluminum tray that sits down there. I couldn't reach it, so figured it would sort itself out on the highway or I'd get it when I have a chance to put her up on the lift.

There is, however, a problem: something smells baaaad when the car has warmed up.

I'm no expert, but it doesn't smell like burning clutch, brake, plastic, or oil. It smells fetid and organic (my girlfriend said "rotting pumpkin", but I thought it may've been a rodent that died somewhere, hence the title) but can only be detected when the vent is set to NOT recirculate or when the top is down (or from outside after stopping with hot engine). It takes about 10m of driving to warm things up enough to smell. I didn't notice it when idling for 10m from cold start. Turning the recirculate on seems to make it much better, as long as top is up.

I've thrown some moisture absorber packets behind the seat and a couple bags of activated charcoal to absorb the smell, but it's not really helping much.

Any ideas of where to look? I can likely use a lift sometime this weekend.

A cat. A feline. Yup. ;)

Drive for 10-15 mins to verify that the odor is still present, then;

- Put it on the lift and inspect under the car (and retrieve your lost screwdriver). You may have to remove some underbody panels.
- Lower the car, remove the top engine cover, and inspect the top of the engine
- Remove the front engine cover (behind the seats) and inspect the front of the engine
- If still nothing, check around the radiators at the front of the car

Not sure if the cabin air filter configuration is the same on the 987 as 986. Look under the plastic panel to the left of the battery where the filter is located. I’ve had mice nest in that area before as well as on the filter itself.

“Fresh Cab” http://https://www.amazon.com/Fresh-Cab-Botanical-Repellent-Pouches/dp/B00L236OMW
has worked well for me in keeping the little critters at bay

You really should retrieve that screwdriver as soon as possible. If you “let it take care of itself”, who knows where it will end up. Into a following motorcyclist, an unlucky pedestrian, or through some poor motorist’s tire?

I’ve actually seen that happen during a race. A screwdriver fell out of the car in front of me and another car ran over it. It ruined his tire (and race).

Good point, noted. I'll hopefully have it lifted tomorrow.

My daughters Subaru had a full blown rabbits nest built into the top of her engine. Didn’t know it was there until we smelled a slight burning smell. I wish I had a picture, it was quite a feat of critter engineering. Fortunately the critter was not cooked. It was the craziest thing I think I’ve ever seen on an engine. Our cars have lots of nooks and crannies for critters to invade. Check your front end too around your radiators, those are easy access critter cages for sure...

My 986 developed a bad smell. I searched all over but finally found an expired critter under the passenger seat. Also, there is a plastic panel above the passenger foot area held in with a few plastic fasteners. When lowered, I discovered the nest which consisted of insulation stuff scavenged from around the car, plus a lot of critter poop.