Removed my battery, and the battery tray. Under the tray was a very small dia plastic line running to the firewall. Does anyone know what that line is for? My first guess is that it is a vac line related to the temp control.

Thanks. Tim in Maricopa AridZona

 

Correct, that is the vacuum line to the interior AC controls and vents. Often when people hear a clicking under that dash it is because this has developed either a hole or split from battery acid.

 

Thanks, that is exactly what happened - discovered a hole in the line.

 

I'll have to pull my battery out this afternoon. I've had that clicking for a while and I thought it was a faulty resistor pack. I changed out the resistor pack but no luck.

 

Had a friend with a coupe come by and her rough idle was caused by that, except the line was broken where it enters the firewall from the manifold. Fixed it with some small rubber vacuum tubing to join the 2 sections.

 

Right after I spliced mine with a vacuum hose I had the actuator for the recirculating flap go and it also caused clicking. That part number for that is A2028001875. That is a Mercedes part number.

 

I also have a loud clicking noise coming from the dash area when 1st starting the car ! Not all the time & last for just 5 to 10 seconds ! Could this be the problem ?

 

I too found this line under my battery tray but I don't know where the end in the engine compartment is attached. I haven't had any operational problems with this line disconnected. So where does it go? Answer: It goes to the manifold on the drivers side next to the throttle body.

See pictures in post 14 for repair.

 

The end in the engine compartment attaches to the intake manifold.

 

So anyone know why I'm getting the loud ticking noise coming from dash when I 1st start car ? It last for 5 to 10 seconds then goes way but doesn't always do it !

 

"top - drivers side" from the throttle body..

 

I thought that line was "rat nip" Mine was chewed!

Les

 

Oh trust me it is.. I fixed the wife's roadster 3 times.. and they went after my roadsters.. I purchased a stainless steel braid for tubing.. So unless they find some steroids somewhere they are done snacking on it..

 

Vacuum LIne from Engine to Heater Controls/Heater Fan

Pictures show where this line is located in the engine compartment.

Overview of engine compartment with line under the battery going toward the throttle body.
.....Arrow on the left is between the firewall & the heat shield.
.....Remove the screw in the heat shield at the right arrow to get better access to the line if there is a break in that area.

Line under battery holder.
Area between the firewall & heat shield where I repaired the line with rubber hose.
Line going into the manifold on the drivers side next to the throttle body.

 

Wow awesome pic & write up ! Just another great place to get info on our cross fires !! Great job thanks !