2000 Millenium Edition Millenia ?s

[BDSCRPN#1]

I'm new to owning a Mazda, however have owned a number of varied makes models of most everything else. No stranger to working on any type of engine except this Miller cycle. Really not much of a difference diagnosing or anything but....

...This 2.3 miller cycle is a bit of a puzzler with these know oil burning issues. Question is, any mechanics figure out the cause of the problem or is this a Mazda Engineering issue that they will not share with the general public? I understand the bearing issues with the Lysholm SC, not a problem cause, found the replacement parts through an SC rebuild site. Problem is the time it take to do the work and the seemingly idiotic design in the first place. I'm figuring that the issue stems from infrequent oil changes causing the vacuum lines to clog and pcv and egr valves to malfunction. Thus in turn causing coking of oil in the SC and the oil pan which causes this sc bearing to have blow by due to sludge and 'oil cheese' in them. The graphite bearing seals just can't move correctly and thus oil in the charge air and intake system causing these otherwise amazing engines to foul badly.

Please correct me if I'm wrong or anyone has practical first hand knowledge of these engines. I have a number of other questions about this engine as I would like to 'enhance' the performance. But need to sort out this oil burning issue first. Also is it common for the valve cover gaskets to leak? Cause this one is and unfortunately due to design placement the Alternator is getting doused in oil.

I do have the full gasket kit or this engine already but wanting to see what input I can get and suggestions for better fuel economy and or power output I can find prior to full tear down. ie better pistons heads, blow-by valve replacement, exhaust systems, or whatever. Basically find the best course for this car either go economy fuel consumption or can this thing zoom zoom!

[Saint_]

Switch 2.3L cams with 2.5 ones and you will have the full blast of the s/c. If you dont blow anything it beat beat the h. out...

[keninn]

i think you first should read up more on miller cycle. then read up more on the mazda 2.3 miller cycle. cause you are dreaming

[BDSCRPN]

I have read up a considerable amount on the miller cycle engine and the primary difference has to do with cam time for exhaust valves more so than anything else. That and it has a modified lysholm supercharger, which apparently the parent version of this compressor didn't have the oil coking issue this version has. Or at least not reported but maybe a handful of times that I could find for the original version. So the issue has to be with the redesign or the way it is applied on this engine. When i first saw this engine it shocked me that the compressor was under the intak instead of on top or to the side of it. I know that can cause an issue with the heat displacement. But seemed initially not to much of an issue with the charged air inter-coolers and the general placement of everything. Also if was really an issue these cars probably never would have reached the mileage they have.

So again this leads me to my original post and that maybe this is either a longterm build up issue or some sort of part breakdown or failure issue that wasn't expected to occur as quickly or the cars not expected to last as long.

Now as for performance and making this car go zoom zoom. Why the **** not, it is still a combustion engine and is supercharged? So why cant it go zoom zoom? the supercharger could have been made smaller of less compression and car still woulda performed great. But they bumped it up and give it more power than really needed. So that leaves room for improvement to make it produce even more. Typically the engines are designed with less power provided than what they really can dish out.

However on the other hand isn't the Miller cycle supposed to provide a smaller package with equivalent output as their larger otto cycle counter parts. Thus making them more efficient, which means we could make them even more efficient than they do from the factory.

[millyowner]

4 speed auto = no zoom zoom. Sorry for any bruised feelings out there but it's the truth.

As for oil burning, mine has close to 150,000 miles on it and I use about a quart of oil every 5,000 miles.

Original oil specs for the miller cycle call for dino 10w30 changed every 7,500 miles for schedule 1 or every 5,000 miles for schedule 2. Schedule 1 is for Grandma Jones driving 55mph cross-country on the interstate. Schedule 2 is for everyone else. Problem is that a lot of these cars got schedule 1 maintenance during their warranty period when Mazda Service was doing the oil changes when they should have gotten schedule 2 and these SCs do not take well to deteriorated oil. Mine has had schedule 2 since new, so I'm not surprised I don't have puffs of blue smoke when I cold start it in the mornings.

Other than valve timing, the miller cycle is no different from any other forced induction engine. If you were to switch it to a more traditional otto cycle configuration, you'd gain a bit of HP and lose a bit of economy. That's it.

[Saint_]

How in the world you are using only 1 qt per 5000mi but i am burning 1 qt per 1500miles? We have same mileage. My intercoolers are bare dry, valve covers have no leak, it is leaking internally to the cylinders.

[99SnowWhiteMillyS]

Are you the original owner of your Millenia Saint? Mine uses up about 1/4 - 1/2 quart per 3,000 miles. I'm sure a lot of the variance is due to how these cars were treated the first couple years of their lives.

Forgot to add I'm at 132,000 miles currently.

[ME2000]

Originally Posted by Saint_

How in the world you are using only 1 qt per 5000mi but i am burning 1 qt per 1500miles? We have same mileage. My intercoolers are bare dry, valve covers have no leak, it is leaking internally to the cylinders.

My car wasn't much of an oil burner. It was a few thousand miles before the big 100K milestone. If that motor is ever sold out of that car, someone has a **** good motor. I got very little puff of smoke, but that was on mornings where it was freezing. I really do miss that car.

[Crackberri]

Originally Posted by BDSCRPN

I have read up a considerable amount on the miller cycle engine and the primary difference has to do with cam time for exhaust valves more so than anything else.

Don’t want to rain on your parade but it is the delayed intake valve closing which is the secret sauce of the Miller Cycle.

[Saint_]

Originally Posted by 99SnowWhiteMillyS

Are you the original owner of your Millenia Saint? Mine uses up about 1/4 - 1/2 quart per 3,000 miles. I'm sure a lot of the variance is due to how these cars were treated the first couple years of their lives.

Forgot to add I'm at 132,000 miles currently.

Nope I have have it since 100k miles. It happened after synthetic, now I am back to dino but still burning.