02 VVT oil pressure loss
 

My motor spun a bearing in September and the thread for that is here

I dropped the motor back in in January.

https://lh4.googleusercontent.com/-O...o/DSC_2802.JPG

Problem is that I continued getting the P0012 code. During the rebuild I had disassembled the VVT actuator and cleaned it so am confident I DO NOT need to use a high detergent oil to regain it's function. I also replaced the Orings in the "adapter".

I read every post I could find re the Miata P0012 code and decided to replace the ECU which did not help.

So I started suspecting OIL PRESSURE. The oil control system is a hydraulic system after all. After hooking up a mechanical pressure gauge to the port before the VVT actuator I found oil pressure that fluctuates wildly from 70psi peg with cold oil then falls on its face then back to 40, 60 and idles at <10 and maxes at ~40 with warm oil. So I started to blame the pressure relief valve in the oil pump and then replaced that. NO HELP :facepalm:

This video is oil temp @~190


This video is VVT oil line disconnected and gauge screwed into the block. 60+ PSI @ 3K AND IDLES @ 35 LBS!!!!!



So after much toil and coin I'm no closer to a ready to rock motor.

This oil pressure loss in the Oil Control System is what caused the engine failure to begin with. I have not revved this new motor over 6k more than twice for a short time and so when I dropped the pan to change the pump there was NO foreign matter in the bottom. So there's that.

I know the pressure is being lost in the VVT system but how and how to fix it?.

This thread has some nice info as to the oil flow of this system but where could the loss be?

I'm hoping you replaced the oil pump with one from Boundary Engineering or Mazda and not one from any other source because the VVT pumps are higher volume and some aftermarket suppliers with the local auto parts stores will fudge and say they are interchangeable.

What specific oil are you using? I'm interested in viscosity and not the additives.

Is there any evidence of the plastic base of the dipstick handle melting below the o-ring?

Speaking of o-rings, did your replacement oil pump come with a new one to go between the pump outlet and the block?

For Youtube videos, put the complete address from the top of the page including the "V=" and the string of characters that follows until you reach "&". You can cut the "&" and everything afterwards off. Just paste the address right in with the regular text and it will insert the video there.

Because this car will rarely hit the limiter and retains A/C and PS (street car) I bought the BP6D-14-100 from Rosenthal and it did not come with an Oring (Cheap Bastards) but I had one i used with fresh RTV gasket.

No, no melting on the dipstick handle. Why do you ask?

I seated the rings with 30w then change to Mazda spec 10-30 then tried 40w racing oil which only helped slightly til it warmed up. I'll run 10-30 T5.

It's getting nice out and I really want to drive. I'm fucking sick of working on this thing.




THANKS!!!!!!!!!!!!!!!!!!!!

The dipstick handle can melt within the tube and drip molten plastic into the oil, which then can block oil passages or partially hold open the oil pressure relief valve.

Ah. Nope none of that.

Could the #1 cam bearing be blown out so much that it doesn't keep back pressure in the OCV system? My thoughts are that no, you would likely see just a steady pressure loss and not the bouncing that is occurring.

http://i54.tinypic.com/voo9ag.jpg

http://i52.tinypic.com/2csdzck.jpg

None of you ballerz have a clue?

Ok I read this thread and your engine build thread, and watched your videos in this thread.

Question: Did you remove/clean the oil pressure relief valve in this pump? Is this a mazda VVT oil pump? Is this the pump from your previous motor that had metal in the oil?

Comments: Looks like your relief valve in the engine is sticking. Erratic pressure readings and all.

This is the Mazda VVT pump and I opened it up only to prime it. The erratic pressure had me thinking relief valve too which is why the new pump. Look at the second video again, mo more erratic pressure sans VVT circuit.

Re-replaced the O rings which improved the fluctuation issue but still once oil temp was ~200 maks pressure was 35 PSI.

Next step, pull cam journal and check clearance.

So with engine at idle and cold oil OP read 50 then actuate the solenoid and actuator does its job ,engine dies.


Oil temp reaches 130 then idle OP is 20 and 50 @ 3500rpm. Actuator does nothing at idle but advances timing @ 3.5k

OT hits 170 and idle OP is 15 and 3.5k OP is 35! Timing does not advance under this condition.

I have the #1 journal off but I can't find the plasti gauge so I'll pick up some tomorrow.

Sounds like something is loose. Try heavier weight oil, see if the pressure comes up to acceptable levels. If you've already tried a 10-40 try a 20W-50 motor oil with a new mazda filter. See if that helps enough. If not, you probably gotta pull the cams and check there, or the bottom end has to come apart.

I'd say that's a .004 specs for non VVT motor say .0014 to .003 with max .006

https://lh6.googleusercontent.com/-F...o/DSC_2843.JPG

Is this out of spec enough to cause the pressure loss?

Anyone know VVT journal clearance?

Clearly the journals were scoured but I don't know of any fix other than new head. No one local line bores and besides that would mean all new shims etc.

Ebay shop has reman head for $650 is the rough journals enough reason to spend that much cash?

I can't read the gauge as it's out of focus, but .004 clearance in one bearing is not your problem.

Yeah I'm eliminating possibilities. Where would you look next?

If I were you, I'd try a thicker oil and see what happens.

Basically there are 2 scenarios in my mind.

Scenario 1- if thicker oil = acceptable oil pressure, you're ok with that and it's "fixed".

Scenario 2- In your mind thicker oil is not ok even if it "fixed" the low oil pressure part, in which case you're going to likely be tearing down the engine. At least if you tried thicker oil now and had those numbers, that may help you pinpoint the problem.

There is no reason your car should need thicker oil on stock engine. just my .02

on another note:
Glanced at your thread a couple times per your PM request, and I'm really not seeing anything obvious, so I'm not of much help.

I had a P0010 on mine before, turned out to be wires from the solenoid going to the ecu, I guess they kinda pulled out a little bit from the plug/harness, wiggled them around and it never came back.

https://www.miataturbo.net/build-thr...0/#post1155484

Oh, this is a long shot from hell, but just a random though I had. You didn't remove, and then forget to reinstall your oil squirters did you? If that somehow happened, you'd have 4 holes bypassing oil that would certainly result in low oil pressure. Or maybe one of them fell out. Just a thought!

/\ that might be a possibility, since he did pull apart the whole thing to clean/rebuild

No they're in place I even checked them when I dropped the pan.

Don't forget this thing has fine oil pressure with the VVT oil line disconnected.

I've run 40w in it with no help.

I know that's why I said try 50W.

Regarding VVT line, dunno! If you think that's the issue, pull the vvt mechanism apart and have a look.

9 out of 10 people that took it apart had issues afterwards, including myself with the last built motor I did. I knwo you said you cleaned it, but.......

I've had mine apart twice, it's a pretty simple part. No idea if it works yet, will know soon though. I can't imagine any reason why it wouldn't work though, it's just a few pieces and seals/springs if I remember right, like baby apex seals...

It's apart now I'll see if I can hammer it back together soon. I WANNA DRIVE!

sad ain't it

https://lh3.googleusercontent.com/Lb...=w1230-h824-no

Thought I'd update and bump the thread.

I picked up a new #1 cam bearing and oil pipe (adapter; the part with the o rings) and installed those with no change. Not that I was really surprised but I started doubting my diagnosis and thinking about just getting enough flow to the rotating assembly to handle some RPM without worrying about the valve timing but also ensuring lubrication makes it to the cam bearing and the actuator.

I made 2 block off plates which sandwich under the supply line. The first one had a 1/8" hole drilled into it. This drill size was arrived at by measuring and closely equivalent to the opening in the oil control valve that allows oil to flow past to the moving parts.

Sketchy huh?

https://lh6.googleusercontent.com/-3...o/DSC_2876.JPG

1/8" made little to no difference in upstream oil pressure! But at least it confirms my suspicion that the loss is down stream.

The second plate has a 1/16" hole = 1/4 the area of the first hole. This provides enough oil to the VVT to lubricate while providing 20lb @ 830 rpm and 60lb all the way to 7k rpm with >210* oil!!!!!!

Although this does not provide enough oil for the VVT to function at any level it does

1. Prove the loss is the the VVT system.

2. Provide flow/pressure enough to keep the reciprocating parts happy.

THIS IS A TEMPORARY EXERCISE

Any thoughts?

What would you do next?

1. It proves there is not enough oil volume coming from the pump to feed everything that currently needs to be fed. It does not necessarily villainize the vvt mechanism. The vvt mechanism does require a fair amount of oil, hence the size of the pipe compared to, let's say, a turbo oil feed line. The vvt may still be bad but I wouldn't consider this to be a conclusive deduction.

Update, I got the VVT hooked up and it works fine in my car, and I disasembled/reassembled the VVT actuator before hand. Works fine! Maybe yours is messed up?

Regarding your engine, I'd still try a 50W oil next. It will not flow as easily, thus whatever(s) in your engine that is leaking too much oil will leak LESS and this will result in higher oil pressure. Worth a shot. Otherwise you gotta tear it down and find out where the leak is.

Not true. You could also try this: Disassemble the engine and plug off all the oil holes to the main and rod bearings. Result? VVT will go to working! Cause now it will get plenty of oil!

Sixshooter said it well.

What you need to understand is that the pump does NOT supply pressure. All it does is supply FLOW. It pumps a certain amount of oil. All the restrictions in the system (bearings, oil squirters, VVT thingy, etc) present a RESTRICTION to the flow, and thus the pressure rises because of this restriction. You have a big leak(s) somewhere causing a lot of oil to go to one place and not much going everywhere else, and this also means lower oil pressure.

You can do the same thing with a turbo car. Unhook the blow off valve from the charge pipe and watch all the boost go right out the hole instead of in the engine. No restriction, no pressure.

Ok, granted guys. Using process of elimination, the squirters are installed with the copper washers and locating pins located and torqued to spec. The bottom end has a max clearance of .00225. The head has no cam bearings. So the head is left.

I guess clearancing all the saddles may point to a new head. Anyone know BP6D clearance? My search showed .006 max for 99 and before.

Have you considered removing the squirters and blocking off the feed holes?

--Ian

Also I believe the oil pump has an O-ring at the discharge of the pump IIRC. If that O-ring is missing, bye bye oil pressure? Maybe this is your problem.

Potentially he used the wrong o-ring then, and it's leaking, thus all these problems. Might be onto something!

I have only just considered blocking the squirters.

No massive puddles of oil on the floor to account for this much loss.

My VVT engine has adequate oil pressure with the squirters.

So do tens of thousands of others.

So did yours, before whatever went wrong went wrong.





I'm trying to remember exactly what this area of the oiling system looks like. In the absence of the O-ring, would oil be escaping from the engine onto the garage floor, or merely escaping from a high-pressure area of the engine into a lower-pressure area (eg: the pan)?

Yeah I know, new head or squirters? Or I haven't found the problem yet.

The pump outlet aligns with the block galley and seals with the o ring and/or RTV. If no seal then big leak.

Did the machine shop remove the oil restrictor from the block when cleaning it and not reinstall it?

You haven't found the problem yet. Removing the squirters will help, but it's not the problem. My VVT actuator works at idle in my miata. And I have squirters/stock vvt engine from the oil standpoint.

Try this: Put in 50W motor oil. If pressure goes UP, you have a leak after the pump. If pressure goes DOWN, you have a restriction before the pump (leaking/cracked/clogged pickup tube for example). Try something man! That or tear it down and start going through it.

Curious what is this? I've never heard of it.

https://www.miataturbo.net/attachmen...ine=1429733752


That plug goes in the galley which feeds oil up from the block into the head. It's present in every Miata engine from 1990 through 2005, be it HLA, solid or VVT.

Thanks Joe!

I looked at his engine build thread, and this post shows that piece is in fact installed in his block.

ROFL

I guess I could try 50w although 40w did nada. I'm trying another trick too.

Thanks all, I didn't know what that was either, and thanks Pat for looking up the pic for me!

I blocked the cam cover dumps with JB Weld and drilled to 1/16" which raised idle pressure ~5-8lb but max pressure still 40lb and not enough for VVT operation.

VVT will not operate at 40lbs, huh? That's interesting.

What do you infer from this?

I would just assume that 40psi would be adequate to actuate the system. 40psi is within the parameters of what I would consider normal oil pressure.

It's very slightly below the lower end of the spec (warm @ 3,000 is quoted as 43-56), however it should certainly be adequate to operator the VVT mechanism.

The engine light comes on at ~2500-3000 & ~30-35lb. The VVT may function at higher rpm tho.

That seems reasonable.

(I assume that the CEL is for P0012.)



Just to double-check, you are using engine oil in your engine, and not Italian salad dressing, right?

https://www.miataturbo.net/attachmen...ine=1429803048 = > https://www.miataturbo.net/attachmen...ine=1429803048 :giggle:

Soo, did you ever figure this out? I'm going to look at a car this weekend with a P0012 but maybe I won't bother if it's this much of a pain in the ass.