Oil filter confusion.

[0wrangler4]

Went to change the oil on my TJ (first time since I bought it) and I looked the filter up in the handy little book at the parts store, got home and noticed it was way too small and would not even thread on. So I went back and took the filter that was on it, had the guy look up the filter just incase I misread and it showed the filter I bought that was wrong. So I had him cross reference the old filter and I finally got the right one. Now my reason for the post, anyone have an idea why it takes a bigger one than listed? It's an 04 with the 2.4l.

 

[Chris]

My only guess is that perhaps you bought a oil filter for the 4.0 engine instead of the 2.4?

 

[0wrangler4]

My only guess is that perhaps you bought a oil filter for the 4.0 engine instead of the 2.4?

I thought that too but I double checked and so did mr parts man at the counter. The 2.4 calls for a smaller one than what I took off. The one I took off looks like it's be for a 4.0, much bigger in size and thread size.

 

[Jerry Bransford]

What brand of oil filter book were you looking in? If there's one thing I have discovered in 50+ years of looking in parts books is that they're not infallible with 100% accurate information. Serpentine belts and spark plugs being notable for the guide books not always being reliable on providing accurate information.

 

[0wrangler4]

What brand of oil filter book were you looking in? If there's one thing I have discovered in 50+ years of looking in parts books is that they're not infallible with 100% accurate information. Serpentine belts and spark plugs being notable for the guide books not always being reliable on providing accurate information.

I looked at various brands, Fram being one and it too was smaller than what I took off. Just strange to me, almost seems as if someone put a larger oil filter mount on it. And that makes no sense to me, it's just a stock 2.4. No need for a larger filter.

 

[RaymondT]

There are usually a number of different filters that will physically fit on any motor as long as the nipple thread pitch and size are the same and the seal diameter mates with the machined surface on the block/filter adapter. Doesn't mean they're correct. There's always a large number of shadetree's who think bigger is better and know better than the engineers who designed the engine. There are other, more important factors such as Anti Drain Back Valves, Bypass pressures, the filter media, case construction, etc.

Pick a good quality, reasonably priced filter that has better quality seals and at least a proper spring for the bypass. I prefer WIX or Napa but there are others. Don't fall for the overpriced stuff. Do your homework before you go. All the manufacturers have good catalogs to look up stuff before you head out the door. Last guy I would listen to is the counter dude at a parts chain outlet. Never know their background.