1992 400SE poor heat bad smell

[Maleic]

My car stinks - really. I know this sounds funny but at about the same the heater started to function poorly the car started to smell like something crawled inside and died. I keep my are very clean and have looked for something left inside that spoiled - that's not it.

The heater produces heat, but the blower isn't working very effectively. Is is possible that a small critter has gotten into the heating system somewhere and is clogging it up? Or does this sould like something else

Thank you for your help

[bobs]

Should be pretty easy to diagnose. Have you looked for any telltale fur? Seriously, have you pulled apart the intake side of your A/C and looked? I know that they are famous for collecting leaves and other organic debris. I recently vacuumed out my A/C intake and was amazed by the amount of crud that had accumulated there.

Both my W140s and my former R170-based Crossfire collected amazing amounts of gunk!

[Maleic]

Thanks for the advice. Where is the intake side of the A/C?

[wbrian63]

Open the hood to the 180 degree position. There's a catch on both the left & right hand hinges that stop the hood at the regular 45 degree angle. Open the hood fully, then walk around to the driver's side and pull the latch (on the outside of the hinge) and lift the hood a little more. Then got to the passenger side and do the same thing. The hood should open fully now.

The intake is the large black plastic assembly behind the sub-firewall just behind the engine adjacent to the windshield.

If your car doesn't have a charcoal air filter (identified by no grills in the hood at the rear near the windshield) - then there are 3 or for large phillips-head screws through the top of the "duct" (for lack of a better term). There are also several allen-headed cap screws around the blower housing on the passenger side.

If you do have an activated charcoal filter, AllData says the process to get the duct out is the same. I've never worked on a car with one of those setups, so I can't comment for sure.

You'll also have to remove two vacuum hoses from the blower housing. A 7mm open-end wrench makes this an easy task - just insert the wrench between the end of the hose and the connector it plugs into - wiggle a little and the hose will pop free.

On the driver's side, there are two items to be removed from the duct - a temperature sensor (just a wire with a sensor at the end) that snaps into the duct, and a valve with 2 hoses - just twist the valve to the left and pull it free.

Pull the rubber gasket that sits atop the sub-firewall out - it should just lift right out.

Lift the top of the air duct free from the car. You'll find a treasure-trove of stuff down in there. The blower is covered by an air filter (or should be) which is available from the parts link at the top of the forum pages. I'll bet it's dirty as sin.

Be careful when reinstalling the cover, there are a couple of (by now) really fragile drain tubes attached to the bottom. They need to be coaxed back into their holes in the body.

If these are shredded (mine fell apart in my hands) - they're a cheap dealer part. I do recommend replacing them, as their presence keeps the A/C from pulling under-car fumes in to the climate control system. Replacing mine made a difference in the odors that work their way into the car.

I'm doing all this from memory - hope I haven't missed anything.