Engine Quiz.....

[UrS4boy]

Oil pressure switch, sender and check valve info

answering my own question as it might help somebody (or me in the future when I've forgotten!) part number for the restrictor/non-return valve is 077 103 175 B

I wasn't on this forum in 2004 so I missed your post and replies, etc. However, I have since documented a lot of info about the oil pump, pressure senders, etc. and the check valve, including using ARP main studs that are too long for No. 3, causing the oil pressure check valve to be crushed. This info, including videos showing how the too long studs enter the oil pressure check valve location, is available here:

http://forums.quattroworld.com/s4s6/msgs/96161.phtml