What is this noise from oil cap? And why is there a "gap" in air/oil separator

[MustangNoob]

Why is the rubber sealing visible in air/oil separator. The cap is tight. Driver's side is more visible.
And what is this noise coming from the oil cap?

Car has no issues

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[HWill]

It looks as if your oring might not be in the groove.

Did you just do an oil change. I had a somewhat similar noise after an oil change and it sounds like a solenoid. I was getting a slight bbq tick that would come n go till the car got up to temp.
Mine went away.

 

[MustangNoob]

It looks as if your oring might not be in the groove.

Did you just do an oil change. I had a somewhat similar noise after an oil change and it sounds like a solenoid. I was getting a slight bbq tick that would come n go till the car got up to temp.
Mine went away.

I have done 2 oil changes. The bbq tick appear after the first one. And that is normal.
However this noise is different and it seems is coming from the oil cap. And it does not seem to have any leaks....

 

[MAT1955]

@MustangNoob ....... respectfully, the Mustang BBQ tic is not normal as there is about a 50/50 chance of getting one - apparently for no known reason. That said, Ford has issued a TSB stating that the tic - also found on other Ford vehicles with the Coyote - will not result in future engine damage. When the tic first started being noticed Ford replaced a few Coyotes before halting the process. BTW IMO the best way to avoid the tic (which some friends have on their Mustangs and I find really annoying) is to use a FULL synthetic oil and to pre-fill your oil filter. I have had two oil changes since factory and have not been blessed with the tic yet.

 

[MustangNoob]

@MustangNoob ....... respectfully, the Mustang BBQ tic is not normal as there is about a 50/50 chance of getting one - apparently for no known reason. That said, Ford has issued a TSB stating that the tic - also found on other Ford vehicles with the Coyote - will not result in future engine damage. When the tic first started being noticed Ford replaced a few Coyotes before halting the process. BTW IMO the best way to avoid the tic (which some friends have on their Mustangs and I find really annoying) is to use a FULL synthetic oil and to pre-fill your oil filter. I have had two oil changes since factory and have not been blessed with the tic yet.

well 50% chance to have it or not seems to qualify as "normal" as not having it. If ford said that there is not a problem I wouldn't worry about. The sound might be annoying but that is fine. Will switch to fully synthetic oil next time and see if there is a difference. For now I worry about he noise that seems to be coming from the oil cap....any ideas?

 

[24 vert]

For now I worry about he noise that seems to be coming from the oil cap....any ideas?

Take the oil cap off and see if the gasket underneath is missing. The gasket that goes on the oil cap may potentially fall out during a change. Not typical on something new, usually on older cars but there could be a manufacturing defect that caused the gasket to be loose and to be lost when the cap was previously removed. Take a look. Let us know.
Cheers,
24 Vert

 

[Skye]

The oil cap doesn't appear to be fully seated. It sounds like vacuum is escaping from that area as well. Between the lip of the oil cap and valve cover, there should be no gap. The two are normally flush with one another.

As to the oil separator, the O-ring and container are off by a bit. Seems OK. It doesn't appear to be weeping oil. IIRC, the Ford unit is taken apart to empty it. You can separate the two halves, inspect and possibly re-align. If it keeping a good seal, I'd leave as-is.

 

[MustangNoob]

@Skye @24 vert here are the pictures of the cap and the oil tube.
oring seems to be there but it does appear to have some wear (black spots).
Any possible issues fro the engine if there is indeed vacuum leak ?

 

[Skye]

From the latest photos and the original video, the filler cap is oriented correctly when down. But I cannot tell if it is sitting flush or not.

When the cap is in-place, is the flange of the cap flush with the valve cover? Or, is there a gap? It should be seated and flush.

As to the sounds, the PCV valve is sitting right there. I hear the sound of air passing by. Maybe I'm hearing that.

Often with a vacuum leak, the engine ingests more air than it should, the engine running leaner.

If you confirm the filler cap is seated flush, while the engine is running, I'd run your finger tip around the edge of the filler cap, then around the edge of the oil separator where you've seen that gasket concern. If you do not hear any change, like if you were checking for a leak, I take it as that's just the way it is. If you can change the tone or sound with your finger at some point, that's something to check.

Regarding the O-ring, it'd be a good practice to clean that, remove the deposits with a rag or something. I'd also run that within the seat of the valve cover, to ensure it's clean.

 

[MustangNoob]

From the latest photos and the original video, the filler cap is oriented correctly when down. But I cannot tell if it is sitting flush or not.

When the cap is in-place, is the flange of the cap flush with the valve cover? Or, is there a gap? It should be seated and flush.

As to the sounds, the PCV valve is sitting right there. I hear the sound of air passing by. Maybe I'm hearing that.

Often with a vacuum leak, the engine ingests more air than it should, the engine running leaner.

If you confirm the filler cap is seated flush, while the engine is running, I'd run your finger tip around the edge of the filler cap, then around the edge of the oil separator where you've seen that gasket concern. If you do not hear any change, like if you were checking for a leak, I take it as that's just the way it is. If you can change the tone or sound with your finger at some point, that's something to check.

Regarding the O-ring, it'd be a good practice to clean that, remove the deposits with a rag or something. I'd also run that within the seat of the valve cover, to ensure it's clean.

Just came back from the dealership. They checked out and is the PCV valve (the brown part where the house from are AOS is connected. All normal. The guy suggested if I want to change that valve with a performance one front eh gt500. I was like nah if it normal not needed.

 

[Skye]

That's cool. Always good to have a cold pair of eyes look at a new concern.

Glad things worked out and there were no issues.

 

[24 vert]

Just came back from the dealership. They checked out and is the PCV valve (the brown part where the house from are AOS is connected. All normal. The guy suggested if I want to change that valve with a performance one front eh gt500. I was like nah if it normal not needed.

So in the end, did they say that was the PCV valve rattling / sucking air but it sounded like it was coming from the oil cap?

 

[MustangNoob]

So in the end, did they say that was the PCV valve rattling / sucking air but it sounded like it was coming from the oil cap?

correct. verified via stethoscope.

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