Hey Folks,

Looks like I am throwing codes again...

Any thoughts on what this picture is telling me as to the cause? It looks like oil to my uneducated eyes.



EDIT: I have not yet performed a Carb cleaner spray test for a leak...

Thanks
John

 

My first idea would be that the pcv valve in not working properly so the extra blow-by and oil vapor is entering the air cleaner thru the vent hose coming from the valve cover and being sucked up the intake and that is the oil you are seeing. Sorry about the run-on sentence!

 

Happy New Year eakermeld...

Thank you for the post.

I have some questions...

Would the defect you described in the PCV valve throw those codes? EDIT/UPDATE: I can see the logic that it would... A dirty air filter and or MAF sensor. This makes sense since the last "fix" was replacing the air filter and cleaning the sensor... but of course, it did not last.

If your assessment is correct, where do you think the oil is exiting from (the hose at the intake manifold)?


SO Central Missouri... cool. I have family in Concordia and Sedalia. Watching Mizzou on TV right now.

John

 

There is a hose that comes off of the valve cover (possibly off of the oil filler tube on yours) and goes to the air filter box. It is about a 1/2" to 3/4" hose. With the PCV valve not sucking the excess crankcase pressure out, it is building up and pushing oil vapors thru the said hose into the air box. This hose is actually meant to allow air INTO the crankcase, so it isn't designed to handle what is happening. Check or replace your PCV valve with a good Motorcraft one and check the hose for bad spots and vacuum leaks and replace as necessary. Take a look around for any other vacuum leaks, too. Low vacuum elsewhere in the system will not allow it to work properly also.

GO TIGERS!!!

 

Thank again eakermeld,

I take a look when I get back home in a few days and report back.

If anyone else has any ideas or comments, please chime in.

John

 

Well I did a leak check with some carb cleaner and did not get any change in revs.

I sprayed around the Intake manifolds, PCV line, Air Intake hoses (Filter box to Throttle body).

Will check the PCV valve next.

Does that (PCV Valve) screw off on a 460? The examples I saw on youtube just had folks plucking them from a rubber grommet.

John

 

What about the dual chamber vacuum reservoir on the passenger side fender? There is another small vacuum reservoir on the HVAC blower case too.

I am not a fan of the spray method to find vacuum leaks on a modern EFI engine. Yards of brittle vinyl tubing and multiple vacuum reservoirs are almost too much to overcome with a small stream of carb. cleaner. I test each vacuum circuit with a small hand held vacuum pump/gauge set that I purchased from Harbor Freight years ago.

 

The 7.5L (460 CID) MFI V-8 engine is equipped with a positive closed-type crankcase ventilation system to purge the crankcase vapors. The PCV valve is threaded into the right-hand valve cover and is sealed by a compression gasket.

I was thinking maybe someone put one of those oil impregnated after market bad air cleaners on it.
I had to throw one away that someone put on my 460 before I bought it.

 

The black canaster?

I did not check that. Any good videos on using the device you desribed?

Also... does anyone have a GOOD vacuum diagram?

Thanks
John

 

OKay... so then I do Unscrew the PCV valve.

WHen I looked at the part online late last night it looked likje it came with a nylon gasket on the UN-threaded side??? I did not see another gasket.

 

Airfilter system is stock with I believe a FRAM filter.

 

With all of that on the out side of the parts I would think that it may be coming from the front engine oil seal and blown back up on the engine. It also looks like the right valve cover is leaking oil.

 

I would get rid of the FRAM filter as soon as possible if you like your engine.

 

Hi new here.

I recently had these codes. May I ask what you were doing when the check engine light came on? On my 97 HD (Calif) I was at full throttle pulling my fifthwheel onto the freeway when the check engine light came on. I have a tuner/code reader and pulled over to check it out. Same codes. I called my Master Tec buddy at Ford. He said fuel pump is very common for those codes. I cleared the codes and switch to the rear tank. Full throttle no codes. Switched back to the front tank, codes again. New walbro pumps going in this weekend

 

Yes those are lean codes for each bank. Low fuel pressure will cause those codes (P0171 & P0174).