ride1216

could anyone tell me why i have oil being pulled through my intake into my filter?? realized my oil was low....happen to look at my air filter and oil everywhere...replaced the filter....put oil in...did it again few drives after.

ColoradoJeepXJ

What year and miles? My guess would be blow-by.

19558077

x2

ride1216

1988 around 121,000. i guess a simple compression check would tell me if its blow by?

ColoradoJeepXJ

That's pretty low miles for blow-by, check your compression. I have blow-by in 3 cylinders but I also have 181,000 miles.

Howler_GT

Oil in air filter is not uncommon.

What happens is your CCV (PCV on a 4.0L) gets gunked up and cannot pull a vacuum.
The resulting pressure is scavenged by the intake air, pulling the oil with it.

Most common fix: Clean your CCV.
The CCV is merely an orifice unlike a PCV that has a plunger inside that acts as a one-way valve.
It is the grommeted fitting at the back of the valve cover.

To clean CCV: Remove from valve cover and using a pin/precision screwdriver/piece of wire clean out the orifice in the CCV itself.
Use of brake cleaner is a +.
Then turn your attention to the hard plastic line.
Most times if the CCV is clogged the hard plastic line is to.
Clean it out much like the CCV. Use of compressed air is a +.
Then lastly, the intake fitting.
Thast needs to be cleaned also.
Remove it and clean.

Now sometimes there is so much "junk" that the threaded hole in the intake is blocked. This requires use of a shop-vac. DO NOT HAVE ENGINE RUNNING FOR THIS. Use the "crevis tool" on your shop-vac over the opening while breaking up the obstruction. The object here is to vacuum up as much of this garbage so it doesn't get into the cylinders.

After everything is nice and cleaned....re-assemble.

NOW is a good time to remove your IAT sensor and give it a good cleaning.
IAT=Intake Air Temp.
Tells the PCM/ECU the incoming air temp so it can adjust the air/fuel ratio accordingly.
It gets gunked up with oily reside and gives a false reading, causing more gas to be introduced into the ratio---bad gas mileage.
The IAT in relatively close to the CCV vacuum port on the intake. Usually one intake runner away.

Cleaning: Unclip wires.
Unscrew from intake.
Use brake cleaner THEN Electrical Contact Cleaner.

The "business-end" of the sensor is a small off-white plastic "cage" that protects a light blue diode.
The brake cleaner will remove the oily build-up and then use of the Electrical Contact Cleaner will remove any unwanted residue lefy from the Brake Cleaner that can cause the IAT to be an "oil-magnet" after re-intallation.
IF for some reason the IAT cannot/will not clean up properly, dont fret, they are rather inexpensive (<$12)

Screw IAT back into intake and re-attach wires.


Then remove the fresh air tube on the front breather (the one that goes to the air cleaner) and clean out all the oily residue.
Clean the residue out of air cleaner also, and install a new filter.
After the air cleaner is back together, give the fresh air tube a slight twist as to create a bit of an "uphill" (high spot in center). This makes it harder for any liquid oil to be pulled UP and into the filter

This will go a long way in reducing the amount of oil in the air filter.

ride1216

thanks for the advice...ill clean the CCV and go ahead and do a compression check as well (even though i do have low miles on it) and hopefully be back on here saying that it worked or at least helped eh.