9113300709 Low Oil Pressure Issue

[Haasman]

Should the oil be drained before removing the oil pressure relief spring?

[edmayo]

You don't have to drain it, but you will get a constant stream of oil coming out once the piston comes down. Use a clean drain pan then you can just put the oil back in the engine.

[304065]

Ditto to this. When you remove the cap you will feel the pressure of the spring, it could open your garage door, or so it feels when you are laying under the car with your right hand enveloped in a stream of warm oil. Don't let it shoot into the drain pan or you will have to take a magnet to scoop everything out. Use a copper crush washer when you put everything back and don't forget to torque to 60NM.

[M_deJong]

If you have the slot head cap it will be fun to remove. Ed taught me to use a wide slot blade in a hammer driven impact wrench to remove this, which worked well.

A trick I figured out is to have a spare cap on hand to screw into the hole when you remove the cap/spring/plunger for evaluation. This will keep your oil tank from draining thru the hole while you are at the bench.

Also, pay attention to which cap you have. The original 12mm deep cap has a big head and no grooves. The later 9mm deep cap has a smaller round head and a groove around the head for ID. The hex caps are 9mm deep. This is illustrated in the shop manual. Going from a 12mm cap to a 9mm cap is the equivalent of adding some preload washers to the spring. Unless you care that much about originality, I would use the hex cap just for the ease of use.

[kentf14]

Thanks Mike. I was just wondering (literally) how I was going to get enough torque on the slot head cap.

[304065]

You can buy a P74 (screwdriver head 1/2" drive) from Baum Tools and carefully, carefully file the blade down so it fits in the slot. It will not fit in as-purchased condition. This is to avoid buggering the screwdriver slot for obvious reasons.

[Haasman]

So possibly using the hex cap alone might raise the oil pressure enough? Interesting. Is the hex cap part # easily found on the PET? Does the hex cap also require a sealing crush ring?

I also wonder if the thermostat is opening completely? In the higher ambient temp situation that brought me to start this thread, did the T-stat contributed to the low oil pressure?

[kentf14]

I just ordered a cap, crush washer and spring (super cheap on PP)
Cap: 999-064-026-01-M260
Washer:900-123-106-30-M131
Spring: 901-107-531-01-M260

[Haasman]

Kent- is that the hex cap?

[kentf14]

Getting back to a comment I made previously regarding oil dilution. My pressure dropped when my oil had been diluted out by a stuck MFI thermostat. Apparently when the engine runs super-rich (in start up mode) the oil can be diluted with fuel.
I don't recall if you said that you had checked your oil?