2002 Ranger clicks when idling

[Dingus]

2002 Ranger, manual trans. When idling there is a clicking noise from the engine, almost like a switch being thrown. It occurs every 10-15 seconds, on the first 'half' of the click the RPMs drop, then go back up on the back 'half' click. After a minute or so the clicking (and surging) stops for 30 seconds or so before starting back. The click almost sounds like one of those old oil cans...

 

[Lacky01]

hmmm...

I think thats the AC unit engaging and disengaging. mine does it too but I dont think it does it without the AC being on.

 

[Dingus]

AC is turned off. Is there anything that might cause it to engage?

 

[Damonkr]

I think mine makes that same noise also. I have heard it with my AC off not sure why it does that???

 

[Dingus]

Now that you mention it, it is EXACTLY like the AC kicking in. We did have a problem a while back where the AC would blow cold even when we were on vent and the console switch showed off. That gives me a good starting point.