I went to Murray's a local Auto Part store and they didnt have air filters in stock, in they're system, or in they're hard book for a 4.0 liter. Do I have to buy Fram? Has anyone else had problems locating Motorcraft air filters for the 4.0?

 

Might almost be easier to jsut order one online...

Not sure what your funds allow.. but most of teh comunity here specializes in ordering up K&N, whetehr its a drop in or cold air.. the drop in is usually washable, and allows an awful lto mroe air through, along with much better air filtration.

 

The only downside to a K&N is the oil. It kills your MAF. So plan on cleaning that as well.

As for an air filter, all the big companies make one.

 

I prefer the amsoil filter myself, but I have had good luck with K&N also...

 

The Motorcraft air filter is stupidly over-priced, and is most likely a Purolater. I've always used Wix.

 

Just want to make a clearification. A K&N does NOT filter better. It allows for a higher flow rate at a given Delta P. (pressure change accross the filter)
That reduction in restriction allows for more air flow.. and therefor more TQ *potential*.

Now.. I've personally rebuilt engines that have used K&N filters. And while I do see traces of debris in the intake manifold. I've yet to see valve seat, valve guide, or cylinder ring/wall wear because of the increased debris.

My solution is to run a conical K&N w/a outerwears pre-filter. You get the best of both worlds that way.

Rich