Oil Pump Gerotor Bolts.

[Alucard]

This is a thread about the oil pump gerotor bolts. They come loose over time and oil pressure is lost when they do. This leads eventually leads to engine failure if not some other internal anomaly. There are many theories as to why this happens but the main reason seems to be the different thermal expansion rates between the gerotor housing and steel gerotor when heated. This bolt anomaly is solved by putting Loctite blue on the bolt threads and reinstalling the bolts.

[lord flashheart]

yea its important to also note that an impact driver is required for putting them in properly, and also, there are different pump sizes. the early EJs had had a 7 mm thick pump (shown on the right, hence the "7"). The one on the left is a 10 mm and came on most of the later models. There were also 8s, and 9s. but in 2008 (if memory serves) they went to a 11 mm pump. they were less prone to the screws coming loose.

[Alucard]

yea its important to also note that an impact driver is required for putting them in properly, and also, there are different pump sizes. the early EJs had had a 7 mm thick pump (shown on the right, hence the "7"). The one on the left is a 10 mm and came on most of the later models. There were also 8s, and 9s. but in 2008 (if memory serves) they went to a 11 mm pump. they were less prone to the screws coming loose.

7's and 8's were found in EJ18's and EJ22's. EJ25D's had 8mm oil pumps, but I've found 9's in them as well. EJ22T's and early EJ205/EJ257's had 10mm oil pumps but the 22T pumps flowed a fair bit more due to having to send the oil to squirters. 11mm pumps were used in 2008 indeed, but the bolt issue plagued them as well. My friend just blew a 2012 EJ255 today due to some oil pumps backing out. I'm about to take off my EJ257 pump off my EJ22D and redo the bolts.

[lord flashheart]

that do be a bummer. oil press gauge FTW!