After this months newsletter, just changed my Mobil1 Filter to Bosch

[Corvette95]

Had a brand new Mobil 1 black extended life filter on my 95, after reading Haibecks article I just swapped it with a Bosch 3401 , has anyone tested the Fram PH3985 or the STP S3985 . I also wonder if the extened life Mobile 1 performs any better than the standard Mobil 1 ?

[jonszr1]

I was wondering about the Napa gold also. I heard it was a wix filter and had excellent holding of pressure?Are there any of the high end reusable filters that would be better?

[bobbyhi]

I don't know if Marc tested every oil filter available but if he says to use the Bosch that is what to go with. Can't go wrong with Marc's recommendations.............

[Aurora40]

I'll probably be picking up Bosch in the future as well. Though I'm not so concerned as to go remove the filter on there now to swap it out.

[Hammer]

Originally Posted by Corvette95

Had a brand new Mobil 1 black extended life filter on my 95, after reading Haibecks article I just swapped it with a Bosch 3401 , has anyone tested the Fram PH3985 or the STP S3985 . I also wonder if the extened life Mobile 1 performs any better than the standard Mobil 1 ?

Autozone Bosch filters are $5.99 and usually in stock.

[tf95ZR1]

Originally Posted by Corvette95

Had a brand new Mobil 1 black extended life filter on my 95, after reading Haibecks article I just swapped it with a Bosch 3401 , has anyone tested the Fram PH3985 or the STP S3985 . I also wonder if the extened life Mobile 1 performs any better than the standard Mobil 1 ?

Am I reading the wrong article? Marc's article says the FRAM,
not Mobil 1 filters drain back valve malfunctions. I think either
Mobil 1 or Bosch are OK.
Ted

To quote Marc Haibeck
"As published, in 1997

It May Be Time For More Than Just A Simple Filter Replacement

See the note at the end of this article for the latest filter recommendation dated June 2005

I have discovered that there is a defect in the design of the PF970C oil filter. The anti drain back feature does not function properly.


June 2005

Fram no longer markets the TG3905 filter in the Chicago area. A good filter that is available in this area and works correctly is the Bosch 3401. Auto Zone parts stores stock the Bosch 3401. A plus feature of the 3401 is that it is colored gloss black like the PF970C.

The Mobil 1, M1-207 is also a good choice. The anti drain back valve seals normally. The filter is white in color. Serious LT5 owners will want to paint it black. It is rather expensive. It's available at Auto Zone stores."

[Hammer]

Hi Ted,
Pages 19 and 20 of the current (10/06) Heart of the Beast newsletter has some updated testing by Marc. It reads as follows:

The Bosch Premium 3401 oil filter is a good choice for the LT5. The anti-drainback valve works very well and it has filtration and flow characteristics that are compatible with the PF970C. The manufactures provided the following performance specifications for the original PF970C (early filter) and the Bosch 3401. The testing was performed according to SAE specification HS-806. Filter Single pass particle size at 98% efficiency Flow at 3 psi pressure differential

PF970C 25 microns 7 gal./min.
Bosch 3401 20 microns 12 gal./min.

The anti-drainback system performs poorly on the Mobil 1 M1-207 filter.

Anti-Drainback Test Results
The filters were removed from LT5 engines 8 hours after shutdown. The oil to weight ratio is the weight of the retained oil expressed as a percentage of the total weight of the filter and the oil. The testing was performed with Mobil 1 10W-30 oil. Mobil1 10W-30 oil weighs .94 ounce in mass per fluid ounce of volume.

Filter. Weight when new. Weight after 8 hours. Retained oil weight. Oil to weight ratio.
PF970 14oz. 25oz. 11oz. 44%
PF970C early 15oz. 18oz. 3oz. 17%
PF970C late 15oz. 20oz. 5oz. 25%
PF970C blue 14oz. 22oz. 8oz. 36%
Bosch 3401 13oz. 22oz. 9oz. 41%
Mobil 1 207 17oz. 21oz. 4oz. 19%

Recommendations
The old blue PF970 was the best performer in this test. However, it is no longer available from ACDelco. The Bosch 3401 and the blue PF970C filters are about equal with very good anti-drainback

[Peaven]

Time to get rid of the M1's and go with the Bosch or the Blue 970C.

[tomtom72]

This is proly just "bad luck of the draw" but I recently went thru two M1-207 filters on my 90. Both gave me exceptional chain rattle at start up, even hot start ups were affected and even the gauge was making me think the sensor was going south. They were the black ones, not that I think that matters but I'm not sure it was just "my luck" that I caught two in a row with less than good drain back valves.

I put the bosch on after seeing the threads here and reading the Heart newsletter....man what a difference! Now she's back to business as usual. Hot starts are quiet again and cold starts are back to the usual (for my car anyway) 3-5 seconds or mostly less of faint rattle and the oil pressure gauge is now showing O/P building like it used to before the last two M1's.

I just say thanks to Marc and the other bro's o' the beast for the "head's up"!

Tom