Engine Oil From Air Filter Now Runs Horribly

[downonmonday]

I have a 1995 Ford Cobra (331, vortech supercharger, Anderson Ford piping with Pro-M Airflow meter, etc). The internals I don't know a lot about because the previous owner I bought it from this past fall was Polish and new little English but had the money to get this car built up big time. Anyway, I changed the oil two weeks ago with Joe Gibbs Drive 5w/30 and K&N oil filter. I go to my buddies house for a surprise part and I was surprised instead from oil spot underneath the air filter (behind the splash guard) on the ground. I thought maybe I put too much oil, but I didn't after checking the dip stick. The car ran fine but now all of a sudden I am getting oil through the breather tube that is tied into the supercharger piping where it receives the air after the air filter. Now I take it out today and it is running like butt. Spitting stuttering and sound like misfiring after 2000 RPM. It idles fine at first, but after it gets warm it barely idles. And it still left oil behind after I put it back into the garage. Do you think this oil issue has the MAF all dirty? But at the same time the MAF is getting air from a small area that is isolated from the rest of the Anderson Ford piping. My friend owns his own mechanic shop but is in Vegas for the weekend. I am just trying to wrap my head around this. It happened all of a sudden after an oil change...that is why I am concerned. Thank you in advance!

 

[jsw81]

Are you sure you didn't put too much oil in there? There are 2 drain plugs on the oil pan. Hopefully you drained both.

 

[downonmonday]

Yes drained both. Filled with 5 qts. Checked dipstick it read full. Ran car for a few minutes and checked again. Still in the safe zone.

 

[downonmonday]

I may do a compression check tomorrow?

 

[toyman]

For certain the MAF is coated in oil if it's located downstream from the breather tube. Secondly, I would pull the PCV and replace the screen that sits below the PCV. If it's original it's guaranteed to be plugged with grunge. Also confirm that the PCV is not plugged and the check valve is working as well. If these parts haven't been changed in recent memory buy the complete kit, screen, PCV and grommet. Check the vacuum lines too.

 

[revhead347]

See if your spark plugs are oil fouled too. Unfortunately, the PCV system in a Mustang has a tendency to suck up a lot of oil.

Kurt

 

[downonmonday]

PCV must be buried cause I am not seeing it. I cleaned the air filter and MAF this morning. Waiting for air filter to dry. I am now off to the auto store to buy a PCV kit. I also put 20w-50 in like I did before with no issues. The plugs are dry. They are caramel color. I race 2 stroke motocross, so I'm part expert in oil soaked plugs. lol

 

[downonmonday]

I took pictures of my set up for better help. just need to hop on the phone now to retrieve them.

 

[jAEded]

See if your spark plugs are oil fouled too. Unfortunately, the PCV system in a Mustang has a tendency to suck up a lot of oil.

Kurt

+100 to this.

Elite Engineering PCV catch can. I got tired of pulling my upper and having it full of oil. They make a nice one... I only get 1 to 2 oz of oil per oil change interval so I know my rings aren't too bad. - http://www.eliteengineeringusa.com/pcv-oil-catch-can-and-standard-hardware-mustang/

 

[downonmonday]

Well, I took it out for a test drive and it ran great the first 4 miles. Then it started sputtering, stalling, spitting, erratic RPM's and sadly it died one block from the house. It would not start again. As I was waiting for my brother to help me push it home I could see the oil collecting on the ground from the air filter. I just don't get it? And why all of a sudden after an oil change? (I installed new PCV too)

 

[downonmonday]

 

[mikestang63]

You are probably generating excessive crankcase pressure. On supercharged engines, I replaced my closed breather with an open element style one and replaced my PCV with a turbo coupe check valve PCV and added an oil seperator catch can from JLT. I noticed on your picture your breather cap is closed and there is no vent tube off the filler tube. Also there is no baffle in the VC. The easiest path then for the oil blowback is back out the inlet tube.


As mentioned earlier, are your plugs fouled?

 

[downonmonday]

No the plugs are dry. I am just baffled why now after driving it about a thousand miles since I owned it since August '13 and after an oil change? I'll have to try what you mentioned. Just irritating. lol

I ran the car without the oil fill cap on. The RPM's slowed down and there was no vapor puffs, so a good thing I'd believe. I put the cap back on and unhooked the tube from the supercharger pipping that leads to the air filter and it was sucking in air. I'm just going to try what you mentioned.

 

[mikestang63]

The K&N oil filter you put on may have raised crankcase pressure,, as it is intended for racing applications

 

[downonmonday]

I went back to the exact oil and filter I was using previously when I had no issues. Valvoline 20w/50 and Mobil 1 filter.

 

[mikestang63]

I went back to the exact oil and filter I was using previously when I had no issues. Valvoline 20w/50 and Mobil 1 filter.

Your original post stated you installed a K&N oil filter. Why are you using 20/50 oil as that is robbing you of hp. I run 5w 30 in my mustangs.

 

[downonmonday]

You are probably generating excessive crankcase pressure. On supercharged engines, I replaced my closed breather with an open element style one and replaced my PCV with a turbo coupe check valve PCV and added an oil seperator catch can from JLT. I noticed on your picture your breather cap is closed and there is no vent tube off the filler tube. Also there is no baffle in the VC. The easiest path then for the oil blowback is back out the inlet tube.


As mentioned earlier, are your plugs fouled?

The breather cap is closed, but there is a vent tube off of the filler tube. It's the black hosing from the filler tube to the supercharger piping.

 

[downonmonday]

Your original post stated you installed a K&N oil filter. Why are you using 20/50 oil as that is robbing you of hp. I run 5w 30 in my mustangs.

I changed everything back to the way it was before, so now I'm back to the thick oil and Mobil 1 filter. I tried the 5w-30 and now I have a car thats spewing oil from the air filter and causing the MAF to be saturated in oil.

 

[mikestang63]

The breather cap is closed, but there is a vent tube off of the filler tube. It's the black hosing from the filler tube to the supercharger piping.

wait- you have the vent tube from the VC venting to the supercharger inlet tube? You realize that is why you are sucking oil out of the motor to the MAF.

The viscocity of oil has nothing to do with your problem.

 

[downonmonday]

Yes, I bought the car this way. No problems until now. Should I use the tube as part of the catch can then and seal the hole that is in the SC piping? The tubing is well after the air filter. It goes air filter/MAF, pipe to supercharger that the VC vent tube is connected to, then the supercharger to TB. A reputable builder built the car so I'm just going off of what they have. I'm coming from the motocross world into the drag racing world. Far too many moving parts. lol