1986 Oil Filter

[Ron Earl]

I reciently did an oil change on my 86 coupe, I went to the dealer for my filter because I wanted to be sure I got the right part. The filter they sold me (P/N-25324052) looked smaller than I expected so I questioned it but the guy behind the counter assured me that it was corret. When I installed it I noticed it seamed small in diameter and the rubber gasket appeared to only contact the inner most portion of the mating surface, unfortunately I had already disposed of the old filter so I had nothing to compare.

The kicker is, the reason I was doing the work in the first place is that I removed the engine to address an oil leak. I changed the rear main seal, pan gasket and resealed my oil pressure transmitter and pressure switch. I think I fixed the original leak but now it is leaking again and I think it is the oil filter. Has anyone seen this before?

Ron

[Don G.]

Re: 1986 Oil Filter

When new, your car came with a PF25 oil filter (black in color). The replacement filter at that time supplied by ACDelco was a PF25 ( blue in color). Recently, the PF25 was discontinued and replaced by PF454 (ACDElco part # 25324052). It is shorter in length but exactly the same diameter and sealing surface as the PF25. This filter should not cause a leaking problem unless it has a manufacturing defect.

[Joe L.]

Re: 1986 Oil Filter

Ron-----

Your car originally used an AC PF-25 oil filter. The AC PF-25 was discontinued several years ago and replaced by the PF-454, aka GM #25324052. The PF-454 is about the same OD as the PF-25 but it's quite a bit shorter. However, GM says that it will adequately replace the PF-25, and it's fully approved by GM for use on your engine.

If you wish to use a longer and, presumably, higher capacity filter, you can use a PF-1218. It will provide you with a filter that's a bit longer than the old PF-25 and it will fit and function perfectly.

[John D.]

Re: 1986 Oil Filter

Ron, As mentioned by Don and Joe the original filter for your early C4 was a semi-gloss to gloss black PF 25 with a silver and black decal. These filters were only assembly line filters for the blacked out engine. They were never serviced over the counter. Unless Joe knows differently. Anyhow for NCRS judging the car owners are taking a PF 25 which is readily available all over ebay and also in Canada. Then they are painting it black and putting a repro decal on. My early 84 was one of the first in the country to go to a show with the correct black filter I was told. Now if you are serious about getting the correct PF 25 on then you have to find one that has a rather large round flat spot on the bottom of it. Large means about the size of say a silver dollar. The last ones Delco made (and others) had a round circle about the size of a quarter. Judges are now learning to watch out for this. You often see a fellow on ebay selling the PF 25's real cheap by the case. Well they are the later style but in my opinion better than using the crappy midget filter. Even if you are only driving the car. JD

[Stephen B.]

Re: 1986 Oil Filter

My '86 was purchased new by my father, and I have been the only person to change the oil. The original oil filter was painted black and the size of the PF-25's; however, it did not come with the decal as I've seen on other 86's.

[John D.]

Re: 1986 Oil Filter

Bunky, I do believe that you Dad's new car oil filter came with the AC decal., If it's missing then it fell off. I have proof that they had that decal. You see I have a black PF25 from the assembly line. No it's not for sale gang. Look in the early C4 JM and you will see a photo of the filter that I own. Also one of my friends has a late 84 and still has the original oil filter from it and it has the decal also. IF you like the decal on the black filters you see at the show I know where u can get them. Can't tell you here though as this ain't ebay. JD

[Stephen B.]

Re: 1986 Oil Filter

The decal probably feel off or it was one of those mysteries. The car has another mystery in that the black convertible top did not have any writing. Others are missing the writing. I've been performing my own survey of the convertible top writing along with a survey of the power seat console writing.

[Jim T.]

Re: 1986 Oil Filter

I used the AC Delco 1218 on my 68 and 85 because I have always liked the longer filter. Have used the AC Delco PF35L and the Mobil 1 high efficiency M1-302 on my 70's non original ZZ1 350 crate engine since I use Mobil 1 synthetic oil in it. All these filters will work on Chevy V8's that use a spin on filter from 68 til they started using the smaller diameter filter. After reading on the discussion board that AC Delco was not making all their oil filters months ago the next time I went to buy an oil filter I inspected the AC Delco 1218. I saw that they had changed the mounting flange to what looked like stamped steel. Looked at a similar size box and discovered the AC Delco PF2232. This filter was made with the heavier metal for mounting and had some weight to it and bought it as a replacement. Learned later on this discussion board that the AC Delco PF2232 is the AC Delco filter for Duro Max diesels and has an internal bypass function. Looking inside the filter the spring actuated bypass can be seen.
Folowing from GM Performance Parts catalog. "Synthetic Oil Filter" The PF35L heavy duty spin-on oil filter can replace any PF-25 or PF-35 filter on 1968-90 Chevrolet V8 engines. It has 100% synthetic element that is rated 12 microns. It's synthetic glass filter media provides finer filtration than conventional cellulose (paper) filters. The individual strands of synthetic glass used in the PF35L are smaller and more consistant in size than cellulose fibers. These glass fibers are supported by a polyester sheet laminated on both sides, and the pleated synthetic filter element is backed by a metal screen.
This extremely efficient filter can reduce engine wear by 75% compared to conventional filters without restricting the flow of oil"
I weighed the following filters on post office scales only to see the difference in actual wieghts. They were removed from the box.
AC Delco PF35L 1.8.0 pounds about $10
AC Delco PF2232 1.3.2 pounds about $8
Mobil 1 M1-302 1.4.0 pounds about $10
Purchased at Auto Zone

[Dave P.]

Re: 1986 Oil Filter

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