The K&N 33-2408 is a washable, oiled cotton-gauze panel element for the 5.3L V8 Hummer H3, built to drop into the factory airbox. The manufacturer positions it as a high-airflow filter that keeps filtration levels high enough to protect the engine over the long run. Its listed rating is up to 99% overall filter efficiency, backed by a No-Hassle Lifetime Limited warranty. Owners on user forums have made the case for K&N's oiled media on power grounds, though one long-time K&N user reported oil residue on the MAF sensor and switched to a dry-media filter.
The manufacturer lists this element for the HUMMER H3 V8-5.3L F/I, 2008-2010, so a 2008 5.3L owner can search for a reusable Hummer H3 V8 panel air filter and confirm fit by VIN before ordering. For the swap, the manufacturer's install sheet for the closely related 33-2409 panel filter says the procedure must be followed to ensure the proper fit and seal, with the filter placed into the stock cage, the tabs facing down in the air box, and firm pressure applied towards the sealing area in the air box. The manufacturer's cleaning interval for this filter is every 75,000 miles under normal highway driving conditions, and the re-oiling amount is listed at 1.64 oz.
The manufacturer lists this filter for the 2008-2010 Hummer H3 with the V8-5.3L fuel-injected engine. Confirm your VIN against the manufacturer's application catalog before ordering, since application lists can change.
The manufacturer's install sheet for the closely related 33-2409 panel filter describes it as a direct replacement for the stock element, with no modification required. Confirm this for part 33-2408 with the manufacturer.
Owners on user forums report that oil residue can build up on the mass airflow sensor over time, and some have switched to dry-media filters for that reason. Keep the filter's oil level light when re-oiling and clean the MAF sensor if residue appears.
This is a basic drop-in swap that does not require cutting or modifying the intake. Remove the airbox cover, take out the stock element, and seat the K&N with its tabs facing down, following the manufacturer's sealing procedure so the cover closes without leaks. Clean the airbox sealing surfaces before installing, and use a light touch when closing the cover, since a poor seal lets unfiltered air bypass the element. The install sheet I located was for a sister part number and did not list tools, so confirm the procedure and any required tools with the manufacturer for 33-2408.
