Tin Indian

Went to Autozone to buy an oil filter. They are out of the Delco PF58. Guy looks in the computer and states that it's been replaced (but could not tell me by what)

Then I look at the PF59. What do you know... No anti-drainback valve. Didn't the 59 used to have the valve?

Oh well, I bought a 59 and 6 quarts of Mobil 1 10-30 (from Wallmart).. (they don't sell the Delco filters) Gotta run all over the place!

Ron,

P.S I was going to look at the stock PF44 to see if it had the valve... But they were out of it.

TTopJohn

Stock PF44 doesn't have an anti-drainback valve (at least I can't see anything in there that looks like a valve)

What do you need an anti drainback valve for on a filter that is mounted like ours? Thought that was just needed if the filter was mounted upside down to keep oil from draining out of it.

Tin Indian

John...

Your absolutly right. I can't see how a filter mounted in the vertical would ever need that valve (of course, Patman thinks a little differently)

Now, with a big block MOPAR, it's certainly needed since it's mounted sideways.

I just posted this because I remember the PF-58 had it, and I am positive the 59 did too. Just wondering why these things are being made differently. As far as the 58, I guess the 59 finally replaced it. Hell, they were the same filter anyway from as much as I could tell.

Ron,

Steve Burger

iTrader: (33)

PF44 is not a 44 anymore either. it is a PF46. I went through this at the GMC dealer on the new 03 Denali we just got. I wanted to know if the warranty would be void if I ran a PF58 in that instead of the PF44.

Their answer was it could void the warranty if the dealer was an ***.

Nickn20

I got two replacements for the PF58 from the delco wherehouse, they are PF61 part number now.

Tin Indian

Well well well

Nothing ever stays the same does it.

PF44 GoodBye ... Wecome PF46

PF58 GoodBye ... Welcome PF61

PF59 ... Well, I am sure that number will change very soon too.

So, I wonder what is the difference between the PF61 and the PF59

I can tell you for sure that the 59 does not have the valve. Everything else sure looks the same between the 59 and the old 58.

XLR8NSS

iTrader: (4)

Kimchee and Rice GoodBye ... Welcome Tin Indian :p

Guess I'll have to look for the new numbers when I pick up a new filter. Why do they feel the need to try and confuse people.

Tin Indian

Patman

Both the PF44 and the PF59 have the antidrainback valve, they always have. The PF58 does not. It's extremely odd if you find one without it, it would have to be a production error.

Even with vertical mounts, it's important to have, as it'll hold the oil in place directly above the filter. Without it,this oil will drain back to the pan, so it'll take a second to fill that area. So with this valve, if your filter was horizontal it holds oil inside the filter, when vertical it holds oil above the filter. GM believes it's helpful, otherwise they wouldn't be switching all of their cars over to these types of filters.

I wouldn't bother using AC Delco oil filters anyways, I'd go with K&N or NAPA Gold/Wix/Carquest Premium. Or even the STP/Walmart Supertech.