I ordered what was advertised to be an AC Delco OEM Oil pressure sender on ebay. It was supposed to be part# 12574403. What I got was a slightly different looking unit with part# 12563500. When I look this part number up it comes up with some other brand called Wells Wells or something. It is nearly identical with some small differences, threads are the same. Orifice is larger. I'm tempted just to throw it in because honestly if the OEM one only lasts 50,000 miles, maybe this one will work better. Just a little ticked it was advertised as OEM. I did pay 1/3 of dealer price though so that's a benefit.

 

Well, I stuffed it in there anyways. Threaded fine, connector fit. Moment of truth...

I NOW HAVE OIL PRESSURE!!!

 

I received a response from the seller on ebay:

Our inventory is numbered 12563500 which was the GM part number. GM superseded this number by 12574403 but our inventory predates the part number change. I can assure you that these numbers are equivalent. There are many aftermarket equivalents and this list includes Wells. Wells uses a different numbering system and I believe they use part number PS631 for there equivalent sensor. Any part which is stamped with a GM part number is either a genuine GM part or an illegal counterfeit. A company like Wells would never stamp the GM part number on their parts. I can assure you that this is not Wells but a genuine GM part. Thank you for contacting us and if there is anything else we can help you with, feel free to email or call. Thank you.