What can cause...

[Speedwagon]

Oil to go back down the intake piping, and cover the air filter? And not just a little bit, it seems to be enough to cover the bottom 1/3 of the filter, and then start dripping out of the airbox.

So what types of things can cause this to happen, as it is clearly not normal, and I've never seen it on any other vehicle before.

 

[mhughes165]

blow by, or a inoperative PCV valve

 

[97RangerXLT]

yup.

I hope you have a plugged pcv valve. if not, you are looking at an engine swap

AJ

 

[Mark_88]

Ditto ^

You may also find oil blows out your dipstick if you get too much pressure in the oil pan/head...if your pcv is not plugged it may also be gunk from the EGR built up...that is usually easy to clean out...is this a carbed ro Fuel injected motor?

 

[Will]

Oil to go back down the intake piping, and cover the air filter? And not just a little bit, it seems to be enough to cover the bottom 1/3 of the filter, and then start dripping out of the airbox.

So what types of things can cause this to happen, as it is clearly not normal, and I've never seen it on any other vehicle before.

Here's the nuts and bolts of what these guys are saying:

The crankcase is ventilated in a loop. Clean air is drawn from the engine's air filter, through the crankcase and into the intake manifold below the throttle plate. The PCV valve controls the amount of air allowed to circulate through the loop. You want just a little air at low power settings because you don't want to confuse the fuel system with a big ingest of air under the throttle plates. When the plates are closed and vacuum is high, the PCV valve all but closes and very little air is allowed through the crankcase. When the throttle is open, vacuum is low and the PCV lets the crankcase vent air flow. If the PCV gets plugged, the air won't be allowed to flow and the pressure from blow-by (which a certain amount is normal) will back up the crankcase air feed and go into the air filter. It carries the oil vapor up with it, which condenses back into oil inside the filter.

To build up pressure in the crankcase you would need a blocked line from the engine air filter and the crankcase.

The EGR is an unrelated object.

 

[lil red]

fo sheezy^

na but really, listen to the man
he knows what hes talkin about