Why Was My Old Oil Filter Dry?

[JerryBob]

I removed the filler cap and dipstick on my Tacoma, and drained the oil for about 20 minutes.

I then remove the Mobil 1 M1-102 filter, which sits mounting plate down on this engine. I was expecting oil to seep out, but it was essentially dry.

Could draining the oil have created some sort of vacuum that pulled the oil out of the filter? I never hear any startup noise, and the oil light goes out immediately, so I never had an indication of a problem.

I replaced it with a new Mobil 1 filter since I have it on hand. I guess I'll keep running it since it seems ok.

But just perplexed as to why the old one was dry.

 

[zach1900]

Why would oil come out if your anti drain back valve was doing its job, the oil it stops from draining is in the filter, hence anti-drainback. My Camry 5sfe has its oil filter opening pointed downward, I love this set up.

 

[autoapprentice]

The filter went on bypass. Not a good thing.

 

[zach1900]

Originally Posted By: TanukTun
The filter went on bypass. Not a good thing.
No, it's doing its job.

 

[HerrStig]

Anti drainback valves are not perfect.

 

[autoapprentice]

If the filter was doing its job there would be oil in it.

 

[zach1900]

Originally Posted By: TanukTun
If the filter was doing its job there would be oil in it.
Cut your "dry" filter open then you'll see there is plenty of oil where it belongs.

 

[autoapprentice]

I don't have a dry filter.

 

[zach1900]

Originally Posted By: TanukTun
I don't have a dry filter.

I was referring to the original poster.

 

[autoapprentice]

Well hopefully we can get some pics and I hope all is well with the filter!

 

[zach1900]

Originally Posted By: JerryBob
I removed the filler cap and dipstick on my Tacoma, and drained the oil for about 20 minutes.

I then remove the Mobil 1 M1-102 filter, which sits mounting plate down on this engine. I was expecting oil to seep out, but it was essentially dry.

Could draining the oil have created some sort of vacuum that pulled the oil out of the filter? I never hear any startup noise, and the oil light goes out immediately, so I never had an indication of a problem.

I replaced it with a new Mobil 1 filter since I have it on hand. I guess I'll keep running it since it seems ok.

But just perplexed as to why the old one was dry.
You didn't mention if this is an anomaly on your truck. Let me just on my Toyota every oil filter I have ever used doesn't seep when I pull it off, even upside down, but cutting it open reveals at least 1/4 qt of oil or about 10 oz.

 

[JerryBob]

Originally Posted By: zach1900
Originally Posted By: TanukTun
If the filter was doing its job there would be oil in it.
Cut your "dry" filter open then you'll see there is plenty of oil where it belongs.


I did. It was dry. I could have cut it open on the kitchen table and not have made a mess.

Also, I could tell by weight as soon as I took it off that it was essentially dry.

Here it is right after cutting open. No hemorrhaging of oil. This is showing the seam. The filter looks to be in perfect shape.

The next OCI, I am going to pop off the filter before I drain the oil, to see if the vacuum was causing the drainage.

 

[ARCOgraphite]

Simple(?!)

My new Forester does this. The oil filter is empty at every cold start (or after a hour sit time) Air in the mains drill rises to the high spot in the system and displaces oil out of the filter.

Hot shutdown, thin oil = empty mains up top. Mains drill is not air tight. A shutdown engine sump is open to atmosphere though the 'PVC clean air inlet' at the bung - post-air filter box intake tract.

 

[zach1900]

Originally Posted By: JerryBob
Originally Posted By: zach1900
Originally Posted By: TanukTun
If the filter was doing its job there would be oil in it.
Cut your "dry" filter open then you'll see there is plenty of oil where it belongs.


I did. It was dry. I could have cut it open on the kitchen table and not have made a mess.

Also, I could tell by weight as soon as I took it off that it was essentially dry.
Okay well that's a totally different situation.

 

[ZeeOSix]

Originally Posted By: JerryBob
The next OCI, I am going to pop off the filter before I drain the oil, to see if the vacuum was causing the drainage.


Good test. If it is still empty doing that, then the ADBV was leaking. Of course, the ADBV on this one could have been bad and leaking, whereas the next filter you use might seal 100%.

 

[GravelRoad]

OP, this is normal for a 'mounting end down' filter. My '15 Subaru Forester does the same.

Experiment: Install filter snug, start engine (cold oil start) and run a few seconds, shut off. Quickly remove filter, it will drip oil out (the center hole) making a small mess.

 

[goodtimes]

The way I understand it, it could also be the relief valve leaked air apart from the ADBV. Air is holding the oil in a filter against gravity. A leaking ADBV, relief valve, or a hole in the can on top will allow the oil to leak out. Every pointing down filter I have had makes a mess when the filter is taken off unless it sits like 10 hours. Probably vacuum is holding the oil in the galleries a long time. Both the Maxima and Camry had a cup below the filter, with an outlet lip or a tube to keep the oil from running down the side of the engine. Shops aren't waiting hours. As it is I have/had to still clean oil from the undercover pans, etc. It's a good thing when oil comes out as that means less start up dry.

 

[CT8]

The filter isn't dry. The oil drains from the oil passage ways through the bearings etc and back into the pan. Ya know gravity sucks.

 

[CT8]

Originally Posted By: JerryBob
Originally Posted By: zach1900
Originally Posted By: TanukTun
If the filter was doing its job there would be oil in it.
Cut your "dry" filter open then you'll see there is plenty of oil where it belongs.


I did. It was dry. I could have cut it open on the kitchen table and not have made a mess.

Also, I could tell by weight as soon as I took it off that it was essentially dry.

Here it is right after cutting open. No hemorrhaging of oil. This is showing the seam. The filter looks to be in perfect shape.

The next OCI, I am going to pop off the filter before I drain the oil, to see if the vacuum was causing the drainage.

The filter doesn't look dry to me.

 

[Sayjac]

As speculated, 'could' be the adbv's function was compromised at some point in the oci/fci. Perhaps the vacuum experiment of pulling the filter first may yield a different result. That said, could be the 'next' adbv function my be intact, so that wouldn't be conclusive.

I have no thread end down orientation filter applications, but my filters generally hold oil in that post use position until I do one of two things. Either open an inlet hole or two with toothpick etc. and allow to drain. Or, tap a hole in the dome of the filter which allows the vacuum to release and the oil to drain. Occasionally I might do both but usually the former.

All that said, I never get apoplectic when I read that an adbv may not have functioned at some point in the fci. As long as no significant start up rattle noticed, it could well be a moot point. In your case you said you noticed no start up noise or extended oil light. In many cases imo, even if the adbv didn't function completely it could be much ado about nothing. And even 'some' start up rattle isn't going to grenade the engine, just preferable not to hear one. My .02