1990 reatta ac delco oil filter

[tony1970]

Hi just want to know the difference between an ac oil filter p47 original to the car, and  a ac p47E ?

[padgett]

More holes.

[Barney Eaton]

There is an old post about Reatta oil filters........

The design of the 1988-1990 oil filter adaptor only allows for the use of the "short" PF 47 filter.

If you install a longer PF52 filter it extends below the oil pan and can get damaged.

In 1991 they changed the adaptor so the longer filter can be used....then they changed it again later in the year.

The good news if you want to run a longer ( about 30% larger filter area) filter you can change the adaptor which is readily available

on many 3800 engines starting in 1992.

In the photo below I show all three adaptors as you would look at them as mounted....viewed from the firewall side of the engine.

The 1988 -1990 filter adaptor casting # = 24500345

The early 1991 filter adaptor casting # = 25535435  allows for longer filter but is hard to change.

Sometime in the early months of 1991 the filter adaptor was again changed to casting # 12569220

this allows the use of the longer filter and is easily changed from under the car.

I have also included a picture of 2 different GM sandwich style adaptors so a engine oil cooler can be added.

These adaptors fit between the oil filter adaptor and the oil filter.

The most common one is the most compact and has no casting numbers.

The other one in the picture was on a 3800 front wheel drive Impala with the police option.

it has two different options for the lines and the casting number = 24500032

I also found a filter adaptor on another 3800 police car and the engine oil cooler lines ports were cast into the

adaptor,  but I cannot put my hand on it to give you the casting number.

here are some photos

Edited May 17, 2020 by Barney Eaton (see edit history)

[tony1970]

Thanks Barney for the info.

[padgett]

Had one of them tilted adapters in my 92 Transport. Was a royal pain to reach. I just use 47s and Mobil 1 10w-30 High Milage.in my 88.

[Barney Eaton]

Our 1991 convertible (vin 900552) had the one in the middle....hard to change and oil intentionally dripped into a tray on top of the cradle designed to

catch the oil and funnel it under the car.

When we got the later (vin 901268) it had the later (far right) adaptor and when I looked into them, it was being used on almost every 3800 engine

used in 1991 and later.