Home Forums Gear Hunting Trucks and Four-Wheel Drives Air Filter Check?

I bought a used GMC with a 6.0 last year and it kept throwing a MAFS code so in the process changing it out I noticed one tab of my air filter housing broke off and another stripped leaving just two screws holding it together. This is the same housing that has an air filter indicator on it so I took it to the dealer a couple days ago for an oil change and asked if they opened the air cleaner everytime or just checked the indicator. The reason I asked is that in the heavy equipment business I've been trained to trust the indicator as opening up the filter just for a visual check increases the risk of contaminating the intake with dirt and other crap. I've read literature from Cat that you can't tell if an air filter is plugged just by doing a visual check anyway.

The dealer tech tells me they do a visual all the time as they don't trust the indicator and besides mice, water and other crap can get in the air cleaner box. Now I'm in a quandry. If mice, water and other crap get in the box but aren't plugging the filter enough to trip the indicator what harm are they doing compared to Conan the tech who busts up the air box so it won't seal right just to upsell me an air filter. What say the rest of you that have indicators? Check everytime or leave the the heck alone?

I work in very dusty conditions, and I see air filters that are completely full between the pleats and the indicator is still reading fine. Most times we replace filters on a pickup between 2-4 times a month. I say do a visual check of the filter, don't trust the indicator.

I'd trust a CAT indicator more than a GM one, so look at the filter itself. If you're in dust a lot, keep a closer eye on the filter. Otherwise, give it a look every 15k or so. And by all means, check it yourself, rather than letting others do it. If they don't reseat it correctly, you're at risk of engine damage from dust getting past.

If your intake box is broken, I'd get it replaced ASAP.

We had a guy try to claim us for a Kubota diesel on a straw blower, but we denied it when we found he'd used the wrong size air filter, and the air intake tube was caked all the way to the manifold.

The quick oil change guys used to like to show me my current filter next to a shiny new one to try and get a $36 sale for a $10 filter. After I would tell them, "No!", they'd discover that they'd really screw up their knuckles screwing in that 4th Torx head screw. So, they'd skip it. And I'd get to take care of it at home. Now I waive them off before I even pop the hood.

FC

I had them order a new box on the same R.O. as the oil change so I'll get that changed out as soon as it get's in. When I changed out the MAFS there was a little bird feather caught in the screen. Hmmmmm???? That's why I did the fifty question deal with the dealer. When I bought the truck I was told it was serviced only by the dealer so that leaves little doubt how it broke. I can only question if it isn't the reason the MAFS kept throwing a code too. For the price of the air box and a MAFS I'll manage the filter inspections a lot better from here on out.

Most of the time it is a spider on the mafs. Brake cleaner and an air hose will cure it about half the time. May save you a couple of ducats next time. If not, light and code will come back and just change it then.

And I don't trust the cheap indicators either.