Community Forums

RetiredBob · 04-28-2012, 08:14 AM

What's the consensus--keep the foam pre-filter for the air filter or ditch it?

wb7auk · 04-28-2012, 08:21 AM

Depends on how often you want to change the air filter.

rgreen45 · 04-28-2012, 09:06 AM

Quote:

Originally Posted by wb7auk

Depends on how often you want to change the air filter.

I want to disagree with this. The foam is the primary dispersant of moisture in the air. It allows drier air to enter the paper filtering element. IOW, the foam serves a valuable purpose.

wb7auk · 04-28-2012, 09:36 AM

Quote:

Originally Posted by rgreen45

I want to disagree with this. The foam is the primary dispersant of moisture in the air. It allows drier air to enter the paper filtering element. IOW, the foam serves a valuable purpose.

That is my point. Do not use the pre filter change air filter a lot.

rgreen45 · 04-28-2012, 12:06 PM

Quote:

Originally Posted by wb7auk

That is my point. Do not use the pre filter change air filter a lot.

When the paper gets damp, it both restricts airflow plus clogges easier. When it dries, you'll regain some of the filtration and airflow. Should you drive for 8 hours in the rain however, I think it's costing you in economy and performance without the foam pre-filter in there.

DriVer · 04-28-2012, 05:21 PM

I drove through the remnants of Katrina while going through Louisville. It was raining sideways. My air filter got soaked to the point where I set a DTC and a SES lamp lit up on the IP. We were at the end of the day when all of this happened. I removed the air filter and allowed it to dry overnight in front of a small fan. The next morning I restored the air filter and after I started the engine the SES lamp went out.

I wrung out the foam pre-filter and reused it.

oemtech · 04-29-2012, 02:18 PM

86 the foam pre-filter, as once it gets contaminated with "road grime" it will act as a restriction. Change it more often and your good to go.

Note - The new ones have the foam glued on so you can't take off and clean it.

rgreen45 · 04-29-2012, 06:49 PM

Quote:

Originally Posted by oemtech

86 the foam pre-filter, as once it gets contaminated with "road grime" it will act as a restriction. Change it more often and your good to go.

The more restriction, the better the cleaning until you get to that point of 20"-25" H2O restriction.

If the Big Dogs say trash the foam, go ahead ..... but I never would.

oemtech · 04-29-2012, 06:53 PM

Take a look at the available filters.... 99% will NOT have a foam pre-filter.

rgreen45 · 04-29-2012, 06:57 PM

Quote:

Originally Posted by oemtech

Take a look at the available filters.... 99% will NOT have a foam pre-filter.

Ok.

I gather you're shopping at WMT, AZ, Advance, etc.

oemtech · 04-29-2012, 06:59 PM

Quote:

Originally Posted by rgreen45

Ok.

I gather you're shopping at WMT, AZ, Advance, etc.

Nope... I buy direct from the manufacturer.

rgreen45 · 04-29-2012, 07:02 PM

Quote:

Originally Posted by oemtech

Nope... I buy direct from the manufacturer.

Very good ...

DriVer · 04-29-2012, 08:47 PM

..

√

max49 · 04-29-2012, 10:17 PM

I like the foam pre filter on the 8.1 and the Onan 5500. I don't mind cleaning it and the main filters seem to stay looking like new for a very long time. I guess, possibly our engine might get a little more air with out the foam though. I guess I used to think that when I was in my teens and 20's any way.