What is the "Boost Pressure Solenoid Filter?"

fatweasel · **Posted:** Fri Sep 23, 2011 11:58 am

Maintenance schedule says to replace at 50k miles. Does anyone know what this is?

geordi · **Posted:** Fri Sep 23, 2011 12:22 pm

Yes, its a tiny paper air filter over on the passenger side of the engine bay, in front and below the radiator coolant bottle. I've never replaced mine, but if I was going to, I would probably use one of the Purolator small engine paper fuel filters they have in the parts store for a couple bucks, rather than give any money to a stealer for this. I'm sure they have it listed as a dealer-only part for some insane price.

papaindigo · **Posted:** Fri Sep 23, 2011 12:42 pm

geordi's location description is close but it's not below the coolant bottle at least mine is not. Look along the passenger side of the engine bay along the fender well immediately behind the air filter box, left of and down along the side of the black plastic vacuum bottle and just before the TCM module bolted to the fender well. As geordi notes it's a silly little paper filter that looks for all the world like a paper fuel filter except the bottom side has more holes for air intake. I glance at mine about every oil change or so but in 40K miles it has never shown any evidence of dust but then I don't drive dusty roads much.

The current part # is 5080374AA, dealer ca. $11 vs. online ca. $9. For no good reason I got 1@ for myself and stoutdog as part of another online order to avoid shipping driving up the price but I'm sure geordi's solution would work fine if the silly thing ever got dirty although you would probably have to slightly modify that off end for air intake with careful application of a skil knife or drill.

geordi · **Posted:** Fri Sep 23, 2011 2:03 pm

Heh, I was generalizing about the location a bit b/c it is "below" in the sense that you move down and forward of the coolant bottle to find it... And my plastic mounting of the vacuum box broke a while ago, so mine is just kinda laying in there. You've got the location drilled down tho PapaIndigo, a blind guy could find it with those directions!

With regard to the air flow... I don't think you would need to mod a fuel filter to use that. It wouldn't hurt, but the airflow OUT of the filter into the solenoid goes through the same small hole and tube... So it should be fine entering the filter the same way. The filter would still do its job, b/c while the air might flow faster (low pressure) through a small entry, once inside, the air movement will slow down and the pressure will rise again... And create a kind of "holding area" of slow-moving air which would be actually filtered BETTER b/c of the larger surface area of the fuel filter element.

Ah, whatever. That thing doesn't seem to pass much air anyway, it's only passing the air into the turbo's vacuum actuator. Not much volume to fill up. After 115k miles, it still looks the same to me, no real dirt accumulation at all.

papaindigo · **Posted:** Fri Sep 23, 2011 3:17 pm

Considering the time it took me to find it the first time I figured blind man instructions were good. As to the air flow, you are probably right that a standard paper fuel filter would do just fine without the mod to the intake side I mentioned but being who I am I figured a couple or 3 extra openings on that side wouldn't hurt.

What is the "Boost Pressure Solenoid Filter?"

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