Shimming the oil pump, 3mm, and a how-to with pics.........

[Silver_Bullit]

Ok this procedure took me approximately 4 hours, however that included time to stop now and again to document it. So it should only take about 3 hours from start to finish.

If you don’t like doing general automotive maintenance such as oil changes, tune ups and general work like changing CV shafts, I will advise you that this is a procedure that can really screw up an engine if done wrong, so if you have any doubts about doing this (mechanically) then I say don’t do it. If you do however screw something up while doing this procedure, then I take no responsibility.

All in all this procedure is very well worth doing. I am however not positive about how much my oil pressure increased as I do not have an aftermarket OPSU (oil pressure sending unit) and an aftermarket oil pressure gauge. However, my oil pressure did go up significantly according to the OEM OP gauge. Before doing the procedure my oil pressure ran right on the first line in the low end of the gauge (about ¼” from the red mark) and it only moved about the needles thickness increase oil pressure when revved to 3000 rpm. This really bothered me as I know how the #5 & #6 rod bearings like to starve for oil. Cold starts only saw oil pressures about ½ way between the “L” and the first low mark. All the while I was running 5w30 Syntec.

On a side note, my HLA tick was IMO pretty severe, it could be heard about 50ft from the car when warm, and I knew this was hurting performance and fuel mileage.

You will need an oil change, you don’t have to replace the filter, but why not you’ve gone this far. The oil pan gasket will be about $5 and can be bought at any parts store that carries Fel-Pro.
The Fel-Pro part # is: OS 30909 C


TOOLS NEEDED: : : : : : : : :
Jack, Jack stands, tire removal sockets and wrenches/locks, drain pan, oil/grease rags (several), 10mm socket, 12mm socket, 14mm socket, extension for ratchet being used 4” min., small/medium/large flat blade screwdriver, hammer, 10mm Alan wrench (must be regular style with 90* bend and 3” straight part or there abouts, not the socket kind, short piece of pipe (20”+) to fit over Alan wrench), locktite 242 or higher, torque wrench, razor scraper, wire wheel, new oil pan gasket.

Now you will need a ruler, and a washer that is 1/8th inch, or 3-3.3mm in thickness. I had to use three (3) washers to achieve this thickness.

It is optional to remove the front part of the exhaust. The down pipes and collector. I chose not to.

This is a pic of the oil pump and pressure relief valve..
http://images.cardomain.com/installs...71_43_full.jpg

OK, enough of my rambling now for the Oil Pump shim procedure.

Step#1)
Jack the car up, support with jack stands. Remove R/F (right front) tire. Remove plastic splash shield on the passenger’s side of the car. Drain oil, but leave filter on as you don’t want oil dripping on you the entire time.
http://images.cardomain.com/installs...71_26_full.jpg

Step#2)
Now remove all of the oil pan bolts including the two that are nearest the flywheel. (If they turn hard, then easily turn them ¼ turn at a time, ¼ turn out, ¼ turn in, ½ turn out, ¼ turn in, etc….. until all of the bolts are out.) As seen here:: (~Haynes book pic, hey it was good for something. :grin: )
http://images.cardomain.com/installs...71_34_full.jpg

Step#3)
Take a 14mm (IIRC) wrench or socket and remove the rear most bell housing shield bolt. Optional to remove the other two and remove the shield, I chose to remove it as I wanted to see the flywheel and how much dust was on it. This must be done as the rear 12mm oil pan bolt will not clear the bell housing shield bolt.
Shield bolts:
http://images.cardomain.com/installs...71_32_full.jpg
Oil pan bolts, 12mm.
http://images.cardomain.com/installs...71_33_full.jpg

Step#4)
Now is the fun part. Take the smallest screwdriver and the hammer, drive it under the oil pan edge about ½-3/4 of an inch, then remove and repeat with the next largest screwdriver, repeat previous with large screwdriver. Once the largest screwdriver is under the cover, twist the screwdriver and break the gasket free, use a small screwdriver to aid in the gasket separation all the way around the pan. As seen here:
http://images.cardomain.com/installs...71_29_full.jpg
Aiding with the small screwdriver seen here.
http://images.cardomain.com/installs...71_30_full.jpg

Step#5)
Remove the pan.

Step#6)
This is what you see, the internals of the engine, pickup screen and the dipstick.
http://images.cardomain.com/installs...71_31_full.jpg
The oil relief valve is located above this Alan screw:: (circled in green)
http://images.cardomain.com/installs...71_35_full.jpg

[Silver_Bullit]

Step#7)
Use the 10mm Alan wrench and the short section of pipe to loosen the Alan screw that holds the relief valve in place. This is the reason why the R/F tire had to be removed, as you WILL have to use the pipe. Mine took A LOT of force to loosen, at first I thought that I had broken the Alan wrench. (Must turn toward rear of car to loosen) Seen here:::::
http://images.cardomain.com/installs...71_37_full.jpg

Step#8)
This is the oil relief valve when removed.
http://images.cardomain.com/installs...71_38_full.jpg
As it sits in the car.
http://images.cardomain.com/installs...71_39_full.jpg

Step#9)
Now install the shims, between the Alan screw and the spring.
http://images.cardomain.com/installs...71_41_full.jpg
Note in this pic that the stepped end is facing up, as it goes into the engine first.
http://images.cardomain.com/installs...71_42_full.jpg
The thickness of the shims I used….
http://images.cardomain.com/installs...71_40_full.jpg

Step#10)
Apply some locktite to the threads of the Alan screw and reinstall the relief valve. The valve and casing are machined to be a tight fit so they must be lined up perfectly straight to go back together. Once threaded into place tighten. (I looked for several minuets and couldn’t find a torque spec for the Alan screw so I just tightened to what I considered a tight spec, thus the reason for using the locktite.)

Step#11)
Clean the oil pan gasket surfaces, both oil pan and block sides, with a razor scraper first then with a wire wheel, to ensure a good gasket seal. Make sure all of the old gasket material is out of the pan, off of the mating surface and that there are no foreign objects in the engine/oil pan.
http://images.cardomain.com/installs...71_44_full.jpg

Step#12)
Get the gasket out. (Optional, spray both sides with copper spray and let set)
http://images.cardomain.com/installs...71_45_full.jpg
Slide oil pan into place and start all the oil pan bolts, make sure that the gasket is between the pan and the block when you start the bolts. I started at one end and worked my way around the pan and just started the bolts, not tightening them down or even snuging them. After all the bolts are in and the gasket is aligned properly snug the bolts down and then tighten them down to the following specs:
Long bolts (12mm IIRC) 14-18 lbs
Short bolts (10mm) 71-88 in-lbs
After tightening the bolts down (criss cross tightening fashion, starting in the center and working your way out) go back and double or even triple check the bolts.

Step#13)
Remove the oil filter and let drain, reinstall new filter. Reinstall drain plug in pan, tighten, and fill engine with oil. Check oil level.

Step#14)
STOP!!!!!
Before starting you need to prime the oiling system, as you don’t want to start the engine while all the oil passages are empty of oil.
Open hood, if not already, remove the fuel pump fuse from the engine fuse block. Seen here:::: circled in green, to the left, it is pink::::
http://images.cardomain.com/installs...71_46_full.jpg
Now get in car and crank it over until oil pressure is achieved, may take up to 15 sec or so. Reinstall the fuel pump fuse and double check for oil leaks. Also check the oil level via the dipstick. If you removed the front part of your exhaust, you might want to reinstall it now.

Step #15)
Now is the fun part! Start the car. Immediately get out and look under car for leaks, let it run until it reaches operating temp, the entire time checking for leaks. If there are none congratulations, your done!!! Almost, reinstall the R/F tire and lower the car off of the jack stands.


Double check the oil level for the first couple days to make sure it is at the proper level.

In the results following the procedure, I found that it isn’t a good idea to initially think that it did little good, but it is better to wait for a few miles and then check the pressure difference as it will change slightly upon running the engine a few miles.

My cold start pressure (OEM OPSU and gauge) now reads between the “R” and the “M” and at idle once warm it runs about the needles thickness below the “L”. Wooooo Hoooooooo.!!!!!!!!!!!!!!!!!! My cold starts were half way between the “L” and the first low mark, as stated above, and when warm it was right on the low mark.

Also, as side noted above, this silenced my HLA’s completely. Except for some slight tick upon cold startup and a second or so upon warm startup.


Enjoy!!!

[Rick_96PGT]

Im going to post first, This Rawks.

[Jomanchu]

This sir is my next project. Thanks for the awesome write-up

[Rayman]

spunky

[BeerNuts]

This is now my next project also. I was planning to remove/clean/replace some HLAs, but I'll try this first.

Thanks,

BTW: Can one person have two stickies?

[RigsPGT]

Silver,
im praying for u, so why dont u go out and buy a lottery ticket
Thanks a million times for that perfect write up and pics! This sunday i was suppose to change the oil pan gasket on a 2.5 Millenia and also do the shims on my ZE.




Great Job Man !

[SteveS]

What does oil pressure mean

People don't often understand the function of an engine's lubrication system and just what oil pressure means.

The only reason OEMs install an oil pressure light or oil pressure gauge is because there is no effective and economic way of measuring oil flow rate.

Its the flow rate of the oil which separates the parts in an engine. Its the oil flowing between two offset moving surfaces - scientifically its called hydrodynamic lubrication. More oil flowing between the surfaces means more pressure developed locally right between the movong surfaces and more separation of those surfaces.

Now thats more pressure in the specific area of a bearing or cam and follower, the surfaces are infinitesimally offset and form a wedge into which the oil is forced, not greater oil pressure at the point in the lubrication system where the oil pressure sensor is fitted.

Sure, theres a correlation between oil pressure and oil flow rate, greater pressure will force more oil to flow through the same system. But the mechanics of the oil pump are pretty much stable, its a positive displacement pump where oil flow basically increases as the speed of the pump increases. For a certain speed it will deliver a certain volume of oil. Increased oil pressure could mean a number of things, such as restricted oil pathways and a restricted oil flow rate. There are often design problems with some engines, and from the sound of it Mazda's engineers didn't do the best job designing the oil feed to the 5 and 6 gudgeon pins (rod bearings?).

Lets just consider a couple of extreme cases. We've got an engine where fluid friction in the oil pathways is zero, the oil pressure in this engine will be very low but oil flow rate will be high and all bearings and other sliding surfaces will be separated by a nice thick hydrodynamic fluid film - no wear.

Now this engine is fitted with a tap just on the oil pump outlet, and we slowly close this tap. What happens? The oil pressure goes up, but the oil flow rate goes down, the oil film between the sliding surfaces reduces and those microscopic peaks on even the smoothest polished surface begin to touch each other and wear starts.

Now we completely close the tap, oil pressure reaches its peak but the flow of oil has stopped. No film of oil between sliding surfaces, the surfaces touch, metal welds to metal, generates heat, surfaces break down, loud expensive squealing noise, nearest mechanic rubs hands with glee.

Now shimming the oil pump won't increase oil flow. What is happening is that the oil relief will now open at a higher pressure, so the pressure in the oilways may be slightly higher but there won't be any increase in the flow of oil - thats determined by the speed the oil pump is turning. So no real increase of oil flow rate will have been produced, just a nice increase on the oil pressure gauge. I dont know how it'd be done but really we would want to install a bigger oil pump - we'd see an increase in oil pressure too but there'd be an increased flow of oil through the engine.

Now you can also generate more pressure by changing to a thicker oil, say from an SAE 5W-30 to an SAE 20W-50. The thicker oil will generate more fluid friction psssing through the oilways but less oil will flow and sliding surfaces will in fact move closer together and wear will increase. Another benefit of an SAE 5W-30 engine oil is that it circulates faster to all those furthest away sliding surfaces (yes, our number 5 and 6 gudgeon pins!) on start up so there will be less wear on start up.

So always remember that the vehicle's manufacturer has only put in an oil pressure gauge because there's no accurate and cheap way of measuring the flow rate of oil in an engine. And its flow rate that we want to separate all those moving surfaces.

[Silver_Bullit]

You are very good at writing term papers arn't you.

Yes, it is true that oil pressure isn't as important as volume, however in the case of our engines (KLDE/ZE), with the spring style releif valve, over time the flexing of the spring will cause it to weaken and thus be commpressed more easily. The ideal thing to do is just replace it, but thanks to MAZDA, I doubt that the spring alone can be bought. With the spring compressing more easily than it should, the oil pressure will drop. The oil volume will drop at the same rate because there is oil being bled off before it even enters the oil filter.

I've put 200 miles on my car since doing this. No leaks. The HLA's only tick for about 3-5 sec now on cold start, and they don't tick at all when warm, running or just started. I can however hear that my FGS is bad. It's sound was being masked but the tick of the HLA's.
These results may/will vary from car to car, don't get me wrong, these are just my results.

I am EXTREMELY pleased with the results from doing this.


~Silver

[SteveS]

Ahhhhh, right oh!

Good thinking outside the box Bullit, I hate paying genuine spares prices too, especially when you only want one component of an assembly and not the whole shooting works.

Yeah, I do suffer from verbal diarrhea. I've done little else but write mechanical technical articles and training programs for 20 years and I do get carried away.

At least I see my PGT has the oil pressure gauge right in the middle, so doesn't look like I'm a candidate for your procedure yet ....

[Vseved]

My HLAs will be eternally grateful. Using thin 0W30 oil makes them tick like there is no tomorrow (compared to 10W40 oil).

Also the writeup from SteveS is very good. We need more of this related to our engines.

[spada]

Originally posted by Vseved
My HLAs will be eternally grateful. Using thin 0W30 oil makes them tick like there is no tomorrow (compared to 10W40 oil).

that's gotta be the most opposite phrase i've seen in a while. 0w30 will make it tick LESS. especially on a cold start up. your engine is ticking for another reason other than the oil.

[91PGT]

awsome write up! both of you! i thought it would be harder

i was thinking removing the oil pump or something,