2 Engine AF’s - Time To Change? 19K / 26K Miles

[gathermewool]

~ 3 years on both (in March)
Fram Ultra XGA9997 (4 year, 40K miles Advertised)

15 Legacy: 18948 miles currently on air filter
UOA Comparison
- 15830 miles on AF: 19 ppm Si @ 9843 miles OCI (latest, July)
- 5987 on AF: 15 ppm Si @ 6053 OCI

14 Forester: 25989 miles currently on air filter
UOA Comparison
- 25120 on AF: 34 ppm Si @ 8095 OCI (latest, December
- 4464 on AF: 12 ppm Si @ 5440 OCI

Both filters look dirtier than usual for this mileage, but that’s based on a limited view of the filter.

The new FU filters just came in, so I’m going to just swap them out when I get the chance.

 

[tasch72]

looks like its time for a change on both, especially the forester. I would guesstimate that somewhere between 15k and 20k is the ideal change interval for your area, even though the filter may be rated for 40k miles.

you may want to consider getting a pair of the K&N filter minders for your vehicles to eliminate the guesswork.

 

[gathermewool]

looks like its time for a change on both, especially the forester. I would guesstimate that somewhere between 15k and 20k is the ideal change interval for your area, even though the filter may be rated for 40k miles.

I think you may be right. I was thinking 20-25K max, but I haven’t settle on a number yet. We’ll see how the next run goes.

I also don’t send every oil sample out for analysis, but the latest Forester UOA results show a few things (flash point/viscosity reduction, fuel solution) that I want to check next time, at a reduced OCI.

 

[wpod]

When in doubt change them out.

 

[Rand]

extra dirt from the "hot air intake"?

 

[gathermewool]

extra dirt from the "hot air intake"?

It’s got a snorkus!

 

[gathermewool]

Forgot to update this with my unfortunate findings.

BOTH 9997 filters were too small by over a quarter inch. I barely noticed the gap with the airbox installed. I finagled it in and out, thinking it was simply installed incorrectly, but no. Holding the new one up to the old one made it obvious, too.

Also, the new filters‘ gasket is foam instead of the old felt. The foam is thinner and doesnt cover the entire mating face. It’s awful looking.

I chatted with Fram and Martin seemed indifferent to the fact that either Walmart was selling fakes (less likely) or that Fram had a bad batch that might not be noticed by most people (more likely). I got lucky. I even sent him pics, including all of the numbers on the side of one of the new ones and measurements and he didn’t seem interested. I pushed the point and he said he “can” pass them on. Right…

in the pic, the top is the new one. It wouldn’t be an issue if it actually sealed. To be clear, installed you can see an air gap where unfiltered air would bypass.

 

[gathermewool]

 

[Number_35]

@gathermewool, this makes me consider running a bead of removable caulk around the perimeter of my filters.

My concern with with the pressure gauge in the AF housing is that it won't show evidence of a bad seal or torn filter media.

 

[dogememe]

Huh, that seems like a pretty obvious issue. Designed wrong or just bad QC?

 

[gathermewool]

@gathermewool, this makes me consider running a bead of removable caulk around the perimeter of my filters.

My concern with with the pressure gauge in the AF housing is that it won't show evidence of a bad seal or torn filter media.

Exactly my concern. How many of these are installed that don’t fit but give no indication that they’re bad. I mean, what‘re the chances it will cause engine damage? probably not right away, but after years who knows, especially as the filter reaches capacity and more and more bypasses through that gap.

I actually bought another Fram from Walmart yesterday and it was also too small. Not good.

I’ve got some Wix filter coming in. I’ll update this when I get them.

//

Note: I checked again and even the old Fram filter doesn’t fit the air box perfectly. It barely covers the opening at the too. It should be a little longer.

 

[gathermewool]

Huh, that seems like a pretty obvious issue. Designed wrong or just bad QC?

I bought a third one yesterday and it doesn’t fit either (Same dimensions as the other two).

I‘m going to contact Fram again to let them know. Based on my previous chat they may not care…

Maybe I should contact Walmart too?

 

[twX]

I had the same issue on my Subaru WRX with an AC Delco filter purchased from Amazon. It was slightly shorter in one dimension, and the mounting faces were not completely flat. Unfortunately, I only noticed after checking the airbox and noticing some dust on the clean side. It wasn't an obvious counterfeit, but who knows.

The Subaru airbox design is not great. It's got a hinge on the bottom and clamps up top. If the air filter mounting face is a bit thin or warped, it won't seal well. It's also easy to put the airbox back together without the bottom hinge properly in it's slot.

I went back to the OEM filter, which has a much more solid and straight construction and the proper dimensions. I added some synthetic PTFE-based grease to the felt seal in order to hopefully help with any potential sealing issues.

 

[gathermewool]

I had the same issue on my Subaru WRX with an AC Delco filter purchased from Amazon. It was slightly shorter in one dimension, and the mounting faces were not completely flat. Unfortunately, I only noticed after checking the airbox and noticing some dust on the clean side. It wasn't an obvious counterfeit, but who knows.

The Subaru airbox design is not great. It's got a hinge on the bottom and clamps up top. If the air filter mounting face is a bit thin or warped, it won't seal well. It's also easy to put the airbox back together without the bottom hinge properly in it's slot.

I went back to the OEM filter, which has a much more solid and straight construction and the proper dimensions. I added some synthetic PTFE-based grease to the felt seal in order to hopefully help with any potential sealing issues.

You're absolutely right about the box. The location and ability to remove the snorkus to easily inspect the dirty side of the filter is nice, but it takes some care to get the filter installed properly.

It you don’t remove the bottom it’s very tough to slide a new filter in. It’s definitely doable, but there’s the risk of damaging the filter. The only way to do it perfectly is to disconnect the mount and move the box away farther to get a good angle of attack. This is what I’ll do when the Wix comes in.

Are you concerned about the grease seeping past the gasket and potentially fouling the MAF? I’d be tempted to use some rubber gasket material to thicken things up and create a better seal, but doubling up gaskets on some application us obviously a very bad idea. I’m not sure about his case, where the vacuum would help with the seal.

 

[twX]

Are you concerned about the grease seeping past the gasket and potentially fouling the MAF? I’d be tempted to use some rubber gasket material to thicken things up and create a better seal, but doubling up gaskets on some application us obviously a very bad idea. I’m not sure about his case, where the vacuum would help with the seal.

I just installed it with the grease within the past couple hundred km. I'll check the airbox in a while to check for signs of dust on the clean side of the airbox and for signs of grease seepage. So far, the MAF readings on my datalogs during WOT pulls are pretty much identical to previous pulls that were done with similar intake temperatures and boost, so no signs of bad MAF readings yet.

I chose the PTFE grease since it should be safe for the engine and O2 sensor, as well as rubber and plastic. I would imagine that it would still cause issues with the MAF sensor if enough of it seeps out.

I considered a second gasket as well, but had the same concerns.

 

[totegoat]

I'd change the filters and wash the engines.

 

[benjamming]

Why not just run OEM air filters?

 

[gathermewool]

Why not just run OEM air filters?

Why not run aftermarket?

 

[gathermewool]

I'd change the filters and wash the engines.

I’m changing the filters.

Don’t plan to wash the engines.

 

[loneryder]

I had the same issue on my Subaru WRX with an AC Delco filter purchased from Amazon. It was slightly shorter in one dimension, and the mounting faces were not completely flat. Unfortunately, I only noticed after checking the airbox and noticing some dust on the clean side. It wasn't an obvious counterfeit, but who knows.

The Subaru airbox design is not great. It's got a hinge on the bottom and clamps up top. If the air filter mounting face is a bit thin or warped, it won't seal well. It's also easy to put the airbox back together without the bottom hinge properly in it's slot.

I went back to the OEM filter, which has a much more solid and straight construction and the proper dimensions. I added some synthetic PTFE-based grease to the felt seal in order to hopefully help with any potential sealing issues.

I’ve run into this a lot with aftermarket AF’s in several Mercedes and a Ford truck. Mann Oem are the only ones that fit correctl.