So I am changing the spark plug wires in my Discovery. I have removed the coil pack and see two black plastic tubing hoses.


One I identified as the transmission vent. I will have to repair this line because it got on something hot and completely melted it closed.


The tubing I am trying to identify is the small black tubing that goes up the firewall behind the AC lines and then loops back down. You can see it in the picture... what is this line?


BTW, the person who designed the coil pack location is sadistic!!

 

Looks like another vent tube that comes from the back of the trans and loops up and back to an open end.


Looks like it is the blue tubing in the picture below.

 

Transmission & Transfer Case Vents

 

And there is a front differential vent in there somewhere also.

 

Front diff vent runs along behind the brake booster up against the bulkhead and stops right before the bulkhead goes back for the Transmission hump.

 

X1 ............. there are various vent tubes, some come up on the bulkhead firewall and others from the axles elsewhere. If you are seeing these tubes on the firewall they are usually the transfer box and the autobox vents.

 

Thanks for all the replies! I repaired the broken / melted vent line and finished the Plug wire and sparkplug change.


Combined with the front O2 sensor replacement I did today, it is running much smoother!