Napa Silver 31085 cut open

[Garak]

Originally Posted By: jeepman3071
Ohh I see now, that is an Auto Extra part number not a Wix part number, because the Wix filters starting with "5" have the Silicone valve.

Not always. The Wix 51358 I regularly use on my G37 has a nitrile ADBV.

 

[DSparks]

The way i see it..if it works and for 25.99/cs to your door who cares if its nitrile or silicone......yes there is some sarcasm here lol...worth it just to not have to drive down the street and deal with humans lol

 

[Sayjac]

With few exceptions, Wix/Napa Gold oil filters have silicone adbv's and metal thread end bypass.

 

[Drew99GT]

Originally Posted By: dlundblad
What exactly is the combo valve?



It's a combination antidrainback valve and bypass valve; it's the rubber thingy in the photos. It fits into the outlet hole of the filter center tube and divides oil flow between the inlet of the filter element and the outlet hole in the center tube based on bypass pressure. It also has the anti drainback valve diaphragm built into it that sits flush against the inlet base plate.

 

[ZeeOSix]

Originally Posted By: Drew99GT
Originally Posted By: dlundblad
What exactly is the combo valve?



It's a combination antidrainback valve and bypass valve; it's the rubber thingy in the photos. It fits into the outlet hole of the filter center tube and divides oil flow between the inlet of the filter element and the outlet hole in the center tube based on bypass pressure. It also has the anti drainback valve diaphragm built into it that sits flush against the inlet base plate.


It works like this: The red arrow shows oil flow past the ADBV flap part of the combo valve. The blue arrow shows the path of the oil when the combo valve goes into bypass. The delta-p pushes the annular section of the combo valve inward and allows oil to bypass the media and go into the center tube. The combo valve is also a base end bypass valve as you can see.

I drew the blue arrow's oil flow path a little incorrect, as it would obviously turn 180 and point going out the base plate of the filter and into the engine. You get the basic idea.

 

[Jimmy9190]

Thanks to OP for cutting the filter and posting the pics. I am using a 31085 on my Dakota now and had been thinking of changing to a different filter because my oil pressure was not reading quite exactly the same as it had with the Purolator Classic I had been using for years up until their recent media problems. I think now I will keep using the Napa Silver. It is definitely a quality built filter and the nitrile ADBV does not really matter much anyway since the filter mounts on an angle, not straight up but it is enough to keep plenty of oil in the filter when I shut off the engine.

I may do like others have suggested and maybe try a different oil on my next oil change, maybe go back to Quaker State Conventional or Valvoline Conventional/Napa brand and see how the pressure reads then. It is not enough of a difference to worry about anyway. Dodge oil pressure gauges are not exactly known for their accuracy.

I had thought about and seriously considered switching to the Fram orange can on my truck but after reading here and other sites there have just been too many reported problems with Fram for me to feel confident about using Fram. You hardly if ever hear about problems with Wix filters. I have used plenty of the Wix-made Napa Proselect and Carquest Red Label filters and never had any problems with any of them. I will use the Napa Silver on my truck and Napa Gold on my wife's new Nissan Rogue.

 

[jeepman3071]

Originally Posted By: Jimmy9190
Thanks to OP for cutting the filter and posting the pics. I am using a 31085 on my Dakota now and had been thinking of changing to a different filter because my oil pressure was not reading quite exactly the same as it had with the Purolator Classic I had been using for years up until their recent media problems. I think now I will keep using the Napa Silver. It is definitely a quality built filter and the nitrile ADBV does not really matter much anyway since the filter mounts on an angle, not straight up but it is enough to keep plenty of oil in the filter when I shut off the engine.

I may do like others have suggested and maybe try a different oil on my next oil change, maybe go back to Quaker State Conventional or Valvoline Conventional/Napa brand and see how the pressure reads then. It is not enough of a difference to worry about anyway. Dodge oil pressure gauges are not exactly known for their accuracy.

I had thought about and seriously considered switching to the Fram orange can on my truck but after reading here and other sites there have just been too many reported problems with Fram for me to feel confident about using Fram. You hardly if ever hear about problems with Wix filters. I have used plenty of the Wix-made Napa Proselect and Carquest Red Label filters and never had any problems with any of them. I will use the Napa Silver on my truck and Napa Gold on my wife's new Nissan Rogue.


Hi Jimmy,

You're welcome for cutting the filter. I'm always interested to see what is inside and I'm big on getting the best quality for the money. I feel this filter is a great value considering it costs less than the Purolator Classic. My only issue is finding it. The closest Napa only stocks the Golds, but the one that is a bit further away stocks the Silvers. I'm looking into buying them in bulk so I don't have to make as many trips that way.

As far as the oil pressure in your truck, if you used the same weight oil as last change I'd definitely look into the oil pressure sending unit. They are notorious for going bad on Chrysler vehicles.

 

[Jimmy9190]

I changed the OPSU about a year and a half ago, put in an Echlin SU from Napa and it does read better than the OE part did. My original SU would make the gauge swing back and forth like a metronome. It may be a wiring connector problem because I have wiggled the connector and had the gauge read better. It is not much of a fluctuation or difference, just reads a hair lower between 1000 and 1500 RPM than it did with a Puro Classic. I need to clean the wire connector before I blame the filter but it is not really that big of a problem to begin with. They say that with a Dodge oil pressure gauge as long as the needle is between the high and low hash marks all is well.

 

[jorton]

Is Oreillys Microgard filter same as NAPA silver?

 

[Sayjac]

Originally Posted By: jorton
Is Oreillys Microgard filter same as NAPA silver?

There is no definitive/authoritative answer to that question afaik. The construction is quite similar to the Silver, and therefore it is close. That said, I believe the MG to be most similar to or same as the Wix made Napa ProSelect which is also Napa's value tier non synthetic filter. I believe the shown Auto Extra to be in the same class as the MG and NPS.