No oil pressure after rod bearings

[scotty737]

Hi everyone,

So I just completed my rod bearing job with bmw shells. I filled the car up with oil, a liter in the oil filter housing, and then cranked it without the fuel pump fuse. 3 10 second bursts in an attempt to build pressure. I hooked everything back up and started the car and it ran for 4 seconds without the red oil pressure light going out, so I turned it off. Opened the oil filter housing and see that there is not a bunch of oil in there so I assume the pump is not pushing oil up. Is there something I’m missing here? The only thing I can think of is that the oil suction tube ORING fcp sent me seemed a bit small compared to the one that came off and maybe it is not creating a good enough seal.

thanks

[Icecream]

When I did mine I had all plugs put, cranked for 15 or so seconds two or three times until the oil pressure light turned off. Then buttoned up, started.
If you are sure it is reassembled correctly, if it were me, i'd remove spark plugs to minize load (and potential damage) and allow the starter to turn a good rpm until the red light goes out. Then proceed.

[scotty737]

When I did mine I had all plugs put, cranked for 15 or so seconds two or three times until the oil pressure light turned off. Then buttoned up, started.
If you are sure it is reassembled correctly, if it were me, i'd remove spark plugs to minize load (and potential damage) and allow the starter to turn a good rpm until the red light goes out. Then proceed.

Yes, I did the initial cranking with the spark plugs out. I guess I can remove them and try again.

[Slideways]

After an oil change, the oil light usually takes a second or two longer to go out compared to when starting it normally. You might have turned off the engine right before the light was going to go out. As long as you lubricated a new oring during install, it should be fine and still build oil pressure even if it got a small tear. The pump is picking up from the front and rear sump. The pipe with the oring is only for the rear sump if I recall.

[scotty737]

After an oil change, the oil light usually takes a second or two longer to go out compared to when starting it normally. You might have turned off the engine right before the light was going to go out. As long as you lubricated a new oring during install, it should be fine and still build oil pressure even if it got a small tear. The pump is picking up from the front and rear sump. The pipe with the oring is only for the rear sump if I recall.

understood, thanks for the info. I pulled the plugs again and will crank some more. I did lubricate the oring upon install with some oil.

[scotty737]

Cranked it again for 15 seconds 3 times. Light didn’t go out during this. Looks like I might be dropping the pan again.

[PHNX636]

Id drop the pan and check over the work. Just for future reference the front pickup only transfers oil to the rear sump.

[scotty737]

Id drop the pan and check over the work. Just for future reference the front pickup only transfers oil to the rear sump.

I’m betting money it is the suction tube oring. I knew it didn’t look right when I put it on. Not looking forward to pulling the pan again haha. Just put in the FCP order for replacement

[sapote]

The only thing I can think of is that the oil suction tube ORING fcp sent me seemed a bit small compared to the one that came off and maybe it is not creating a good enough seal.

When install the tube with O-ring, it should slide in with resistance of O-ring being compressed. If not then the pump will suck in thin air molecules.

[George Hill]

My experience has been that it's not uncommon for the oil pressure light to NOT go out in this situation until the engine is running.

Personally I would start it and run it longer OR I would pour some oil into the oil filter housing and start it.

What did you lubricate the bearings with? Assembly lube or 10w/60?

[scotty737]

My experience has been that it's not uncommon for the oil pressure light to NOT go out in this situation until the engine is running.

Personally I would start it and run it longer OR I would pour some oil into the oil filter housing and start it.

What did you lubricate the bearings with? Assembly lube or 10w/60?

Redline assembly Lube.

[George Hill]

Run it... or have you already?

[scotty737]

Run it... or have you already?

I have not started it since the OP. I am going to drop the pan again to double check. It is not worth the risk to me. Car is also an hour and a half away from me at the moment so might be a couple weeks.

[scotty737]

So I just received the box from FCP. They 100% sent me the wrong oring last time. What a waste of my time and potential damage.

[scotty737]

Just wanted to follow up on this. It was the oring. Car started and light went out in a second.