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Oil around valve cover filler cap

Huicho417 said:
Should the hose be relocated to the side of the air filter? If so I may have to look for a different air filter housing . The only option on this one is at the bottom.
Click to expand...
Pull the hose off the air cleaner and breather. Take some steel wool and put it in the breather hose attach to keep bugs/ mice out. Run it and see if the issue goes away..
 
From what I see you should be ok. That leads me to believe you have to much blowby.
 
Thank you for the feedback everyone!

In an effort to correctly understand the positive crankcase ventilation system in an engine. I have a more technical question. The system works by fresh air input thorough the air filter via the tube into the oil cap/breather. Then works it way through the engine block and lastly exiting out through the PCV back into the intake. Am I correct in this sequence of events?

If so, and if I apply simple logical thinking I should not see any blowby if I remove the oil filler cap. However, there should be some minimal blowby if I remove the PCV.

I will run the engine when I get home and remove both the cap and PCV separately to see how much blowby if any is present. Hopefully I can load a video here to show everyone what I find.
 
Huicho417 said:
Thank you for the feedback everyone!

In an effort to correctly understand the positive crankcase ventilation system in an engine. I have a more technical question. The system works by fresh air input thorough the air filter via the tube into the oil cap/breather. Then works it way through the engine block and lastly exiting out through the PCV back into the intake. Am I correct in this sequence of events?

If so, and if I apply simple logical thinking I should not see any blowby if I remove the oil filler cap. However, there should be some minimal blowby if I remove the PCV.

I will run the engine when I get home and remove both the cap and PCV separately to see how much blowby if any is present. Hopefully I can load a video here to show everyone what I find.
Click to expand...
Air in through the breather, blowby out through the pcv into the carb or intake. Into the carb is preferred because it dispersed it to all the cylinders through the carb. If it goes to the intake, it is fed to a particular cylinder runner (or runners). The carb also provides more vacuum than a intake runner might. Low pcv vacuum may cause your issues. Running it through a catch can may aggravate that as well.
 
chy_PCV.jpg
 
With the engine running you should be able to "suck" the PCV valve to your thumb if you pull it out of the valve cover grommet.
The suction is generally reasonably strong if yours is to weak it could be the problem - or part of it.
 
Here is a link to a video of the engine running while I remove both the pcv and oil cap. I also checked for the suction on the pcv removed and happy to report is was strong as mentioned.



Also ran a test for compression and attached is an image of the results, average of 151 psi with a variance over all of 3 psi. Good results according to service manual.

ED2FAA8F-ABC6-4431-B69D-3C54A9739839.jpeg
 
Run a stock PCV valve and run it like the factory set up to see what it does. Why are you running that set up anyway? Another quick test is plug the left valve cover. Remove the PCV valve and run the motor. You should get some light positive pressure out of the right cover.
 
Do you happen to know the part number to an oem pcv?

I added the catch can because I was noticing oil in the hose from pcv to carburetor base. I had a light burnt oil smell when accelerating on the highway. The smell did go away when I added the catch can.

What’s the verdict on the blow-by shown in the video, is it within normal??
 
Huicho417 said:
Do you happen to know the part number to an oem pcv?

I added the catch can because I was noticing oil in the hose from pcv to carburetor base. I had a light burnt oil smell when accelerating on the highway. The smell did go away when I added the catch can.

What’s the verdict on the blow-by shown in the video, is it within normal??
Click to expand...
Well oil in the hose is one sign of to much blow by. Oil weeping from that breather is a sign of to much blow by. Does any oil weep up the dipstick tube? Do as I suggested and video tape it. Are there baffles in the valve covers?
 
connect the PCV valve hose directoy to the base of the carb abd see if the problem goes away. if so, you found your problem.

If not, you have a blow by issue

fyi, a little oil there is not uncommon
 
I would also get rid of the extra hose going to the air cleaner. A simple vented cap has a lot more negative pressure than suckling extra air from somewhere else.
 
That air inlet tube does not necessarily need to go to the air cleaner base or the filter lid - but it is the way many OE manufacturers including Mopar did the PCV system until I guess accountants decided they could save 30 cents per vehicle and simply have the air inlet on the valve cover.
The reason the tube goes up to the air cleaner is the PCV does not operate at wide open throttle due to the lack of inlet manifold vacuum. The tube up in to the air filter allows the engine to still vent crankcase pressure and re-burn any vented fumes.
 
steve340 said:
That air inlet tube does not necessarily need to go to the air cleaner base or the filter lid - but it is the way many OE manufacturers including Mopar did the PCV system until I guess accountants decided they could save 30 cents per vehicle and simply have the air inlet on the valve cover.
Click to expand...
Yes but it's actually the opposite. The accountants stuck to their 30 cent savings on the hose as long as they could, until uncle EPA demanded that all cars are built with the closed system. And has been ever since.
 
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