Savington

iTrader: (31)

For what it's worth, I have never had to shopvac-prime a new motor with a BE pump. Pull the plugs, unplug the CAS, crank the motor until it shows ~20psi of oil pressure, replace plugs and CAS plug, fire.

Joe Perez

iTrader: (8)

Curious as to the reasoning behind this.

Even if a shop-vac were capable of pulling a large amount of vacuum, I can't quite picture how this is supposed to accomplish anything. It's not like you're going to suck oil up past the gears inside the oil pump. If it were possible to do so, the pump wouldn't work very well.

Quintillions of new engines have experienced their first start by just turning the key. A smaller number have been given the luxury treatment of being spun on the starter with the plugs removed and fuel disabled until pressure is achieved. And an even smaller number yet have been externally force-fed oil through a convenient port (such as a hole on the pump-side of an oil filter sandwich plate) prior to ever spinning.

You are the first person I've ever heard of trying to *suck* oil through the engine.

18psi

iTrader: (76)

didn't he have that really odd oiling issue when he just built it?
something about clogged passage going to the filter?

aidandj

iTrader: (5)

Different build.

shuiend

iTrader: (24)

Maybe, I have never had issues. It is a risk I will take.

Here are some pictures of the side of the gears.
On the outside gear, pitting on the forward part, scoring on the inside walls.


On the inside gear, scoring on the part the forward part, pitting on the inside part. Scoring and pitting match in the same contact points of both gears.


Inside of the inner gear. Mostly light pitting.


Oil pick up tube screen, these flakes are aluminum as far as I can tell. I could not get them to stick to a magnet.


Here is the device.


What is funny is using a shop vac to prime the pump and check if the relief valve is installed advice was given to me in this thread. 5 years ago when I did not first install the relief valve. The theory was that if I did not pack my oil pump well enough with lube there could be air in there causing the motor to not prime. So the vacuum pulls the air and the oil up and out. It is just an additional test to see if there are blockages in the oil passages. Here was a quick google search result showing I am not completely crazy.

When I spun out thrust bearing due to glow shift blockage, my machinist suggested that the lack of oil while trying to crank with the starter could have done it. He did not like priming the motor that way. He also suggested the shop vac trick for future use. So this last time when I went to prime the motor I used it to be sure. I got oil pressure right away, and honestly probably did not need to do it. After previous problems, I was not going to risk it.

As to why I checked with that before pulling the motor, it was just another sanity check.

sixshooter

iTrader: (12)

Rod bearing, main bearing, crankshaft, thrust bearing, cam bearing, cam journal, cam lobe, lifter face, lifter body, lifter bore, piston skirt, piston ring, cylinder wall, wrist pin, turbo bearings, to name a few sources of debris or wear metal. Then, of course there is the possible importation of debris and metal in the oil pan, the crankcase of the block, oil galleries of the block, oil galleries of the crank, oil galleries of the head, around the valve pockets of the head, the oil cooler, the oil feeds lines, the oil return lines, the pickup tube, the PCV chambers, the dipstick tube (that was my source once), the oil drain cavity of the turbo, and more. But you are right, debris could only have been generated by the oil pump and not simply ingested by the oil pump.

That's not how this works. That's not how any of this works.

Have you ever even seen a set of Miata oil pump gears? I'm asking this seriously because there really is no good reason for you to ask your question if you had.

Our little rotor and ring of our pumps DO draw oil in from their side into the void created betwixt them. And what do you think would happen if some foreign particles and pieces were carried along the exposed face as the little pickup window went out of view and they were dragged between the gears and the side wall of the pump? If the particles were marshmallows and graham crackers then probably nothing. If the little particles were any of a few different metals, sand, hard carbon, or kitten teeth, then wear would occur. As it ingests more debris and generates even more metal itself other components quickly wear as well in a rapid downward spiral.

But you are right, it has to be the oil pump because you have some personal issue with Boundary or your uncle's boyfriend's cousin had one that failed once and that time it was almost certainly the oil pump just like it is this time.

18psi

iTrader: (76)

found the problem

patsmx5

iTrader: (16)

Does the outer pump gear show the same scratch marks/wear as the inner gear on the sides of the gear where it contacts the oil pump housing? Could only see the inner gear with scratch marks on it from your pics. I realize there is some overlap, since the gear teeth mesh. If the clearance was an issue, the small gear would have wear evenly throughout the gear, and the big gear would only show wear on the part that overlaps with the small gear. The outside of the big gear would be fine.

Six, I know how an oil pump works. I said oil FLOW. Oil leaks past the sides, it doesn't flow through the sides where the gear contacts the housing. The less leakage on the sides, the better the pump works.

I don't run an aftermarket oil pump because I've never had a stock pump fail. I think the stock pumps are more reliable than any other pump. Whether you agree with my opinion, I don't care.

OP did have something go wrong on his motor and I'm helping to diagnose what happened.

You posting 50 things that "could have" cause the problem doesn't help. He needs to know what happened first so he can make sure it never happens again. All this BS aside about what someone think I think, it sucks when an engine breaks and you don't know what even caused it in the first place.

patsmx5

iTrader: (16)

Ok, lets say you're right. You very well could be.

Then the side of the gears facing the inlet/outlet would be chewed up from this debris entering the pump and hitting the side as you say. And the side that's not facing the inlet/outlet would be in much better condition.

Is this the case?

shuiend

iTrader: (24)

Oil pump where it feeds from the pickup tube. You can see scoring all around.


2 of the cylinder walls. Some slight scoring up and down, but fingernail does not catch on any of it.



Rear of the intake cam is discolored. I honestly do not remember if this was there before or not.



The cam cap is does not look horrible. Your fingernail does not catch anywhere.

GeneSplicer

iTrader: (14)

Definitely kitty teeth

sixshooter

iTrader: (12)

WTF happened in that corner of the head? That's very odd. What's the underside of the valve cover look like?

codrus

Yeah, that's the kind of color I associate with motors that went 50K miles without an oil change, but I've never seen it only on PART of an engine.

--Ian

shuiend

iTrader: (24)

I have 2 vvt valve covers, not sure which came with which vvt head. Both look fine underneath in that area.

HHammerly

iTrader: (3)

I also had a hard time priming the last motor, ended up taking out the plug on the oil pump outlet threaded plug and filling it with oil using a siringe it primed right away after that. Still had a few thrust bearing scufs when i took it apart so I changed assembly lube and could feel the pump sucking when i turned the motor over by hand before installing the pickup tube.
I plan on jumping the starter to prime it to avoid having the clutch pressed while doing so, it may not be a bad idea to instal a clutch switch clip if you have a high clamping force presure plate to avoid repeated starts with the clutch on.

Joe Perez

iTrader: (8)

Doesn't everyone bypass the clutch interlock switch as a matter of course?

I've never owned a single car in which that switch lasted longer than a day or so after I purchased it. Had a couple that never came with one in the first place.

sixshooter

iTrader: (12)

That oil varnish due to breakdown is just really strange to see dispersed unevenly. Really strange. It is as though that area was much hotter than the rest. Or something else mysterious happened.

18psi

iTrader: (76)

Like a blocked oil passage to that part of the head?
hmmmmmm

shuiend

iTrader: (24)

I would think that, except for that cam cap is probably the best out of all of them. Which is really weird. I would expect back scoring or something if it was not getting oil.

I probably won't be touching the motor again until sometime next week. Tonight I have some other things to do. Then tomorrow I drive to Pittsburg to pick up a VVT motor and some other stuff, then Saturday drive home and stop by Luke's place to grab his built motor. On Sunday I am going to work on swapping over the VVT head and get the new built motor prepped to be put in.

patsmx5

iTrader: (16)

Cam bearings would be destroyed way before that area became discolored. Aluminum gals very easily when you **** it off.

Been there, done that, destroyed a cam bearing that seized an engine up. Head looked perfect till I started pulling cam caps.