Sniffer is Not Working - PeachParts Mercedes-Benz Forum

BrierS · #1 08-03-2004, 04:23 PM

On my '87 300TD I checked the sampler blower motor, found it works yet possibly weak. With the hose removed, it barely holds a tissue to the port. When plugged back together, I tried what I had read in a couple of LB's posts. At the sensor there is no attempt to draw smoke in. The hose did not seem to be extremely thick walled but on the other hand there certainly is not enough vacuum generated by the Sampler to cause collapse. Has anyone found that the hose has collapsed due to being squeezed too tight within the placement to the sensor?

Thanks.

PS I also tried the trick of disconnecting the electrical plug on the water valve (forward of the battery) and had nice hot air from the sides vents while the A/C was pumping from the center ones.

MikeTangas · #2 08-03-2004, 05:53 PM

The sampler on my 560 was acting just like yours - barely able to hold a single ply of tissue and wouldn't draw smoke, yet I could see it running. I decided the sampler was on it's final leg and installed a new one. ACC has worked fine ever since.

#3 08-03-2004, 06:04 PM

Can you disconnect the blower and slip a piece of flexible tubing on the line so you can blow through the line to ensure that it is clear?

It has to be either what Mike suggests, or the tube is plugged or collapsed. Since these cars are starting to get some years on them now, things like the tube collapsing might be something that happens due to age.

Good luck,

BrierS · #4 08-03-2004, 07:08 PM

Yes. I believe I can get a piece of flex hose on and blow through it. Where as most, from what I have read, have the tube running across with foam, mine travels forward from the blower along the side. There is not much tube to follow with my hand before it makes an upward turn into the voids.

How do these samplers work? They seem like such a small, simple device I would be interested in knowing more about them. Guess that is part of what prompted me to successfully bid the Climate Manual on eBay the other night.

Thanks for the opinions and when I get results I'll post so others can hopefully benefit.

BrierS · #5 08-03-2004, 07:10 PM

PS to my last . . .

If the tube is collapsed, would it work to feed a slightly smaller tube with stiffer wall constuction or is the replacement easier than I imagine?

MikeTangas · #6 08-03-2004, 07:45 PM

Not sure where the intake vent is on your car, on mine it is in the dome light assembly. The tube on the 560 runs up the passenger side A pillar, then across the head piece to the dome light and is made of a black PVC type material. I doubt it will disintegrate like the older foam tubes do.

As I understand the operation of the sampler, the fan spins and due to the position of the tube it creates a vacuum which pulls the sampled air down the tube (simple version). The actual sampling takes place at the intake vent in the dome light assembly.

BrierS · #7 08-03-2004, 08:27 PM

Mike
Mine is the same as you described yours. It does run up the pillar, across under the plastic trim to the center light switch/sunroof. That is where I tested to see if it would draw smoke. I'll try again tomorrow.
Thanks.