: 05 STS V8 Oil filter



malcolm
05-20-05, 02:40 PM
I thing I read here that AC Delco was a decent oil filter. What about the Mobil1 filter? What is the OEM? I would like to change my ownoil but have not had much luck finging the part number for a filter. In addition any hints regarding filter location and drain plug would be appreciated. I have not gotten under the car yet, not as young as I used to be, the less I crawl around on the ground the better.

powerglide
05-20-05, 02:51 PM
I thought AC Delco is the OEM......not sure though.

mtflight
05-20-05, 03:27 PM
The car was validated and tested with the AC Delco filter. Using non-OEM parts, obviously, means you do the testing. Of course, the Mobil 1 filter is a good filter.

I have used both the AC-Delco and the Mobil 1. One argument is that AC-Delco does not filter the smaller particles that the Mobil 1 does, allegedly because it has been determined that the smaller particles are too small to be harmful.

I personally don't think you can go wrong with either filter. I believe # PF61 is the AC-Delco filter, it should be listed on your owner's manual. If going with Mobile, then look it up in the chart.

malcolm
05-20-05, 03:50 PM
mtflight,

I went back to the manual and sure enough on page 6-14 are the filter part numbers PF61. Don't know how I missed the first time around. Thanks

El Dobro
05-21-05, 09:34 AM
The car was validated and tested with the AC Delco filter. Using non-OEM parts, obviously, means you do the testing. Of course, the Mobil 1 filter is a good filter.

I have used both the AC-Delco and the Mobil 1. One argument is that AC-Delco does not filter the smaller particles that the Mobil 1 does, allegedly because it has been determined that the smaller particles are too small to be harmful.

I personally don't think you can go wrong with either filter. I believe # PF61 is the AC-Delco filter, it should be listed on your owner's manual. If going with Mobile, then look it up in the chart.

GM came out with the Ultraguard Gold oil filters and have been discontinuing as they run out of stock. Why? Because they filtered the fine particles so good that they would clog up fast and the oil would then bypass the filter. Finer does not necessarily mean better. The standard AC filter works just fine.

mtflight
05-21-05, 11:45 AM
I had read something along those lines. I'm wondering about the Mobil 1 filter I have in now. Is there a way to know if it goes into bypass mode? My oil changes are around the 5000 mile range and I have no idea whether the filter has been validated for that long an interval--whereas with the OLM we know the AC Delco is.

Last oil change, my oil looked very dark, that's why I thought I'd experiment with the Mobil 1 (I used ACDelco prior to that).

Regards,

Alex

BeelzeBob
05-22-05, 11:12 PM
All oil filters will bypass to some extent on cold starts and/or at higher RPMs. The Northstar engine simply moves way too much oil thru the system at higher RPMs for an oil filter to handle all of it without being restrictive. It will not bypass at the lower RPMs seen during normal driving and such but as the RPM goes above 4500 it will start to bypass to some extent no matter what filter is on the engine.

With a normal engine in service oil filters simply do not gather enough debris to ever clog or cause that much additional restriction. If there was that much debris in the oil then filter clogging would be the least of your worries.

The Delco DuraGuard Gold filters were indeed removed from service....because the finer filter media caused more bypass operation than was warranted or more than could be justified by the finer filtration capability. They did NOT plug too quickly or gather that much more debris as is implied above. The finer filter media simply was a greater restriction to oil flow and, even though it could remove finer particles, it bypassed more often under normal operation....so it is really not the best thing for the engine. It never gathered so much more debris that it clogged quicker causing the bypassing...it simply bypassed more often because of the finer media causing more flow restriction.

You should have no concerns whatsover running an oil filter for 5000 miles....or even 12500 miles on a current model Northstar if you are following the oil life monitor. The oil filter is not catching THAT much debris, trust me.

Take an oil filter that was on the engine for 5000 miles and cut the can open with a large pipe cutter. Use a pipe cutter to avoid generating and additional debris. Take out the fitler paper and examine it for debris. You will find very very little, trust me. Nowhere near enough to plug it or add additional flow restriction.

Most all of the debris an oil filter will catch on an engine is caught during the first 100 miles of the engines life when it is breaking in the cylinder walls. After that, there is simply very very little debris generated. So, it is still a good idea to use a quality oil filter, but the debate over which oil filter is "best" is greatly overblown. Even a crummy oil filter will still catch most all of what it needs to catch after the engine is broken in. The great oil filter debate is largely something theoretical as practically speaking, once an engine is broken in, the oil filter doesn't have THAT much to do. I still recommend the AC Delco filters as that is what was tested with the engine and proven to protect it during breakin as that was the filter that was supplied on the engine from the engine plant. The AC Delco will not blow out the seal or leak in cold weather or collapse the filter media, etc....like some cheap filters will. It is a known, proven entity that is perfectly capable of protecting the engine so I don't know how much "better" any filter could be. But, once broken in, the performance of the oil filter as in regard to an engine's life span and performance is largely moot due to the very little it has to do if the engine is OK otherwise. If something does go wrong to generate wear particles the filter could certainly go a LONG ways to protecting the rest of the engine but some failing is liable to show up anyway if it is generating that much debris.

mtflight
05-22-05, 11:19 PM
Wow bbobinsky. Thanks for the much appreciated enlightenment.

--Alex, a fan of your posts.

Aurora40
06-26-05, 06:00 PM
I still recommend the AC Delco filters as that is what was tested with the engine and proven to protect it during breakin as that was the filter that was supplied on the engine from the engine plant. The AC Delco will not blow out the seal or leak in cold weather or collapse the filter media, etc....like some cheap filters will.

I guess I am late to the table here. I had stockpiled a few Ultraguards when they were discontinued, and just now finally had to buy a new filter. When I went to the local parts store, they had the PF-61 listed in their generic filter book, and no PF-58's on the shelf. So I figured maybe their book was typoed and came home to check the ACDelco website.

They do list the PF-61 now, and so I assume the PF-58 has been discontinued? Reading here, it seems the replacement is not exactly identical and is missing a valve. If I check the AC site for the 2002 STS instead, it lists it as needing the PF-61 and a bypass valve #25013759. Is this the recommended replacement for the PF-58? Using those two things together?

The PF-61 of course was *not* tested with my engine nor proven to protect it during break-in.

Is this filter missing a bypass valve? From what Bbob is saying, they run in bypass at WOT, so I sure as heck don't want the engine starving for oil then. Do I need to buy the ACDelco bypass valve too? And if so, how the heck is it used?

Thanks for any responses or info. I realize it's the "recommended" replacement. But as I also own an LT5, I'm getting used to seeing that often the GM recommended replacement for a part they decide to stop making is inferior to the part it replaces. And I just want what's best for my car.

As a very trivial aside, Bbob, isn't the filter used for break-in actually made by Delphi, and not the AC Delco filter at all? It was on my car, and I recall reading a techline tip about how a tech can use that to see if someone just never changed the oil filter on a car.

Aurora40
06-27-05, 01:29 PM
A little research into the service manual shows that the bypass valve, at least on my car, is built into the oil filter adapter. All the same, I found a place that has a few PF-58's still on the shelf, so I'll be picking those up. :)

BeelzeBob
06-27-05, 02:47 PM
?

The PF-61 of course was *not* tested with my engine nor proven to protect it during break-in.

But as I also own an LT5, I'm getting used to seeing that often the GM recommended replacement for a part they decide to stop making is inferior to the part it replaces. And I just want what's best for my car.

As a very trivial aside, Bbob, isn't the filter used for break-in actually made by Delphi, and not the AC Delco filter at all? It was on my car, and I recall reading a techline tip about how a tech can use that to see if someone just never changed the oil filter on a car.



Not sure of your logic with these comments....

Whenever a part number or design is superceded like that it means that the part is equal or superior to the superceded part. It is tested and validated to prove that. While technically a PF61 was not on your engine during breakin it is on the current FWD engines being manufactured and was tested and validated to protect those engines during breakin....so that retroactively applies to yours.

I would appreciate any examples of GM offering inferior parts for service or for a superceded part number. I doubt that you will be able to offer any. Just because a part is superceded does not mean that the old one (or new one) is inferior.... There are a variety of reasons for supercedeing a part number for service. It isn't something taken lightly nor or the superceding parts ever inferior. Often a minor design change is incorporated and the part number is changed to track the process change...nothing to do with the filter performance or anything affecting it's operation. Sometimes a filter will have a filter bypass valve added even though the engine/oil filter adapter has a bypass valve built in. This just adds a redundant bypass valve and makes servicing older engines with the new filter part number possible. No harm, no foul. Just an extra part that you don't really need but it won't hurt anything at all and is required on the newer generation of engines it applies to. Design changes are often treated that way so that the previous generation of engine can still be serviced with the newer parts to avoid confusion later on in the field....and to minimize the part numbers required to be stocked and the chances of a mistake or getting the wrong filter in the wrong application or mixups in production of the filters later on in the life of both engines. It is a form of error proofing to supercede service part numbers with the latest part both for manufacturing and end use in the field.

You can always be sure that the OEM tests the superceding of things like filters but you CANNOT be sure that an aftermarket manufacturer does this. If the OEM shows a filter being superceded you can be pretty confident of it's usage....not suspect that it is a cheaper or inferior part.

Delphi, yes, technically makes the OEM filter. The AC Delco brand is actually manufactured by a contracted source for service but is spec'd to the original specs and the design, content, source, function, quality, etc...is still controlled by the OEM.

Aurora40
06-27-05, 05:30 PM
I would appreciate any examples of GM offering inferior parts for service or for a superceded part number. I doubt that you will be able to offer any. Just because a part is superceded does not mean that the old one (or new one) is inferior.... There are a variety of reasons for supercedeing a part number for service. It isn't something taken lightly nor or the superceding parts ever inferior. Often a minor design change is incorporated and the part number is changed to track the process change...nothing to do with the filter performance or anything affecting it's operation.

And sometimes a part is superseded with another part that is more common in application to avoid the expense of making low-volume parts for out-of-production cars. Bbob, I absolutely appreciate your taking the time to address this, and I'm glad to hear the PF-61 is in fact in use on new FWD Premium V8's.

A few examples I have seen are the original LT5 spark plugs, #FR2LS with the more common #41-602. I haven't heard of any problems with these plugs, though, and they ought to work just fine. But I doubt they were validated in any way on LT5 motors before the FR2LS was discontinued. Another is the pilot bushing #14061685, which apparently is used on 6.2L diesel truck motors, which of course don't begin to approach the 7,000 rpm redline of the LT5 and have been a problem for several owners. There are probably others, but I haven't owned the car long enough. :) One thing I find quite irritating is the replacement of the spark plug wires from the originals. They originally had "Corvette" and "LT5" printed on red wires, and now for some reason the GM replacements have nothing printed on them. Why change that? Is it expensive to print on the wire wrap? And these wires are not used on any other vehicles, so if they are being made specifically for the LT5, why not keep the printing there?

JohnnyO
07-01-05, 09:55 PM
The Mobil 1 is indeed a great filter, but.... In the Northstar application it is a true P.I.T.A. to thread on because more than one set of threads is cut into the filter and you've got to hit it just right. If you want something a little better than stock, get a K&N (they also have that handy-dandy nut welded on), but the regular AC PF-61 is fine and screws on instantly.

D'Elegance
07-01-05, 11:10 PM
I heard the K&N filter leaves a lot more junk in the oil because theres less filtration because its a "high performance" oil filter and they want less preasure in the system. I find the Purolator Pure One the best filter...........anything except FRAM! :vomit:

powerglide
07-02-05, 12:15 AM
....they're all pretty much the same no?

JohnnyO
07-02-05, 10:01 AM
I heard the K&N filter leaves a lot more junk in the oil because theres less filtration because its a "high performance" oil filter and they want less preasure in the system.
Rumor and speculation. As I recall, the K&N uses a synthetic media instead of paper just like the Mobil 1 filter.

Here are UOA's I did comparing those two filters over 5000 miles. Results are virtually identical.

M1 vs. K&N (http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001349;p=0)