Low oil pressure...

Alright, back under it and the chain tensioner is indeed orange in my motor. Dug one more piece of plastic out of the oil drain pan from the other day and it is indeed black. Looks like the part that broke is something round, short, and perforated. BSD is tight, o ring on the pickup tube looks clean and so does the sealing surface on the pump. Will plastigauge mains and cams tomorrow. Will need to reorder main bolts anyway, so hopefully I can figure out what else needs replacing tomorrow.

 

Well, I think I found my issue. Was dropping the girdle today and taking a peek at the journals and bearings. All but one looked fantastic, but the one exception was exceptionally jacked up. I have never seen a bearing look like this, and I have no idea how/why it does. Hoping that the crank is still good, then I can try to squeeze bearings in without having to separate everything. Or else I will have to pull it again. God I hope that is not the case.

 

Sucks but at the same time, good thing you found it now!

 

True, appears to be in the soft metal of the bearing. The crank has some visual grooves but nothing that feels any different than the other journal when I move my finger/fingernail across the surface. Hoping I can get away with just replacing the bearings. It is at least worth a shot, if it doesn't pan out I will still have to pull it anyway.

 

Same story on both halves of the bearing, and both measure at 0.0965" while spec is 0.0987" - 0.0988". That should do it.

 

Well, back to the drawing board. I replaced the upper bearing in the bad journal, as well as the lower bearing halves of all journals. I plastigauged it after swapping them out, and found myself toward the top of the acceptable bearing clearance range (Standard main journal oil clearance 0.019 - 0.035 mm, Maximum journal clearance 0.10 mm). My reading was approximately the 0.038 mark on green plastigage but may have been a little looser than that. It was, however, under the 0.051 mark. Chalking it up to doing the test with reused main studs, I put it back together to see if it had any impact on my oil pressure. I also installed a new oil pickup tube at this time, as well as a K&N oil filter.

Fire it up, 56 psi. Again. Did not break 56 psi for one second, only dropped from there. I shut the car off when the coolant was 174* and the oil was at 16 psi and dropping. Sigh.

So here I am again, asking myself questions. Even if that main journal was trashed, it still plastigauged at a reasonable value. Combine that with the fact that I added lower bearing halves to all of the other, unaffected journals, you would think that I would have seen a higher cold start pressure (even if just for a few seconds) than the same 56 psi I have been seeing. Again, before all of this, I used to see 82psi at cold start up. Now, I make several changes to components that would affect the oil pressure, and I see the same exact number. This takes me back to when I spun a rod bearing on my ms3. I had a bad rattle and low OP and prayed I could replace the bearings and be ok. I replaced them, and even though the crank was trashed, it still made better pressure after the new bearings. They failed again after a few miles of driving, but there was a change.

This is kind of pointing me to oil pump at this point, but I don't know why or how that could have gone bad. I took my old pickup screen and cut it into pieces. It is entirely intact. Nothing should have been able to pass through the pump.

I am running out of options at this point.

 

Oil pumps can just go bad

 

I sure hope you are right. It was a new pump 10k ago, and had been good to me until I turned the key off last year. It is an ecoboost pump, but my pressures were always in range when it ran. I guess next step is to swap that and cross my fingers. 3rd times the charm?

 

Man I hope the oil pump solves your problem finally. Fixing so bearing tolerances may have been a good thing in the long run if it proves that the oil pump was the issue

 

Good point, I would have never found that bad bearing if I hadn't gone through this fix attempt. That would have caught up quickly, but now I am beginning it believe it may be a product of the real issue.

It's hard not to want to get another Ford pump with a price tag of $85 but I know I should probably get the $225 Mazda pump. Though I am 98% sure they are identical.

 

Dont you have a bad Ford and bad Mazda pump now? Can you year them down to compare?

 

I had a ford oil pump for a motor I recently built. We compared it to a Mazda pump. They appear to be the exact same other then the price.

 

Didn't Lumberjack tear down and compare them with photos on the other place? I forget the technical term, but the ford gears meshed differently. Like the contact area on the gear was further out?

 

Unfortunately the last time I was into the motor was 2017, and I moved since then as well. I'm sure the old pump got thrown away somewhere down the line. But I did order an OEM pump for a reasonable price. Better to shop by part number than name sometimes.

 

Small update, but hoping I found my issue. I got back into the motor after work the past couple nights, and upon disassembly of the timing system, I noticed that my chain tensioner screws were only hand tight. Unlike myself, but I must have neglected to torque them down. I noticed that there is a tiny oil passage on the back of the tensioner, so it is under pressure. I assume that whatever small clearance came to exist between the tensioner and the block would have an impact on pressure. Still swapped the pump, but hopefully this was my issue. I will find out by Saturday, if nothing else comes up.

 

That's interesting. It does look like there is a hole there. Maybe it feeds pressure to it which keeps tension on the chain over time. After looking at the pics though it looks like that bottom one does nothing. I wonder if they large chamber is open at all.

 

I believe that the large port reaches the inlet on the tensioner, circled in red. Very bottom corner of the port. The back of the tensioner was slathered with oil when I took it off, and the inside of the large passage behind it was oily as well. Either way, oil certainly flows through there and is not intended to leak past the tensioner mech.

 

I actually have a block sitting in the garage. I will investigate when I get a chance.

 

Man it sucks that it was something so dumb. But I'm glad that it was something so dumb

 

Hey don't jinx me now!

I am with you though, at least it helped me find that ugly bearing. Whether that was preexisting or caused by this issue, glad I went through that trouble.