I have a 2004 Ranger with a Duratec 2.3 liter 4 banger stick shift. I took it to the Ford dealer a couple weeks ago for an oil & filter change; I got it back and drove it for a couple weeks, but I kept smelling some sort of fumes as I drove it... like I was catching the exhaust from a motorcycle. I figured that maybe there was some engine oil spilled on an exhaust pipe, or some such. Finally, this afternoon I got fed up with the smell, and I popped the hood for a peek... sure enough, the oil filler cap was missing. Snooping around, I saw the oil filler cap stuck beneath the hood latch assembly in front of the radiator. So, I popped it back on, and the stink disappeared.

My question: With the oil filler wide open, shouldn't the engine computer throw a code? It didn't. Seems to me that at least the PCV system should show a failure.

Thanks for whatever help you guys have...

 

How wet is the engine with oil that blew out??? I'd call the Dealer Service Manager & explain what you found, hopefully you took some photos, & tell him you expect another oil & filter change as you don't know how much in the way of contaminates have gotten into the engine. Take your service receipt with you so they know which tech did the work.

There is a specification for crank case pressurization/blow by, that can be measured with gauge but I don't know if your year model has a mounted sensor for that that would trip the CEL/SES light

Let us know what you decide to do.

 

There is no sensor that detects crankcase pressure or PCV system flow. The only symptom, beyond the odor you perceived, would be a possible change in idle speed as the PCV would have a little less restriction on the air coming into the crankcase, but not much.
The flow is filtered air from the intake tube into the cam cover, through the crankcase, out through the separator, through the PCV and into the intake. More or less.
The only thing a missing cap did was allow unfiltered air, with a little less restriction, into the crankcase. And the fumes to escape.
tom

 

Wow that was a great explanation Tom,,, you have a good handle on these old Rangers

 

They screwed up and you are giving them a chance to use your vehicle to screw up again? To each their own.
I bought a new vehicle from Ford back in the late 80s and they gave me "free oil changes for life" on the vehicle. (It was their policy on every new vehicle they sold. I couldn't get them to lower the price if I didn't participate) ON THE VERY FIRST OIL CHANGE, they stripped the plug. One must remember that the "tech" changing your oil at the dealership are usually the lowest of the low. (Sorry, if any of the readers change oil at a dealership and you are the best)
Just tell the dealership owner exactly why you won't be going to them ever again.