Trust the dipstick?. 2000 Mazda Millenia 2.3l

[silveralfa]

I have a 2000 Mazda Millenia with the 2.3 liter Miller cycle engine, which is supercharged. I bought this car from my neighbor who bought it used 12 years ago and has always had it serviced at the dealer. When I changed the oil and filter I put in 4 quarts of oil per the owners manual. When I checked the after starting the car and letting the oil drain back the dipstick showed the engine to be more than a quart low.

I bought a 5 quart bottle of oil at Napa and there is a little less than 1 quart left.

My instinct is that the dipstick from some other car is in there by mistake, what do you think?

This is a unique motor, I think, and there is no sense the sump was replaced.

Trust the dipstick or the specs?

Topic

[Lorrin Barth]

What does the owner’s manual say the oil capacity is?

[Ingvar]

Cool engine
[i]
A Miller-cycle engine is very similar to an Otto-cycle engine. The Miller-cycle uses pistons, valves, a spark plug, etc., just like an Otto-cycle engine does. There are two big differences:

A Miller-cycle engine depends on a supercharger.
A Miller-cycle engine leaves the intake valve open during part of the compression stroke, so that the engine is compressing against the pressure of the supercharger rather than the pressure of the cylinder walls. The effect is increased efficiency, at a level of about 15 percent.[/i]

Guarantee you you are not checking oil level right. We had Mazdaspeed (what a POC) and had same issue. You need to find out how Mazda wants you to check on oil level. I honestly forgot, but it was something strange, like you have to start>run for yey many minutes>shut down and measure right away. Weird. But it’s Mazda.

[silveralfa]

4.0 US qt is what the manual says

[silveralfa]

I am for sure pushing the dipstick all the way in.

I am waiting several minutes for the oil to drain back into the sump before I check it.

I guess my question is whether it’s possible that the capacity of the sump is like 5.5 qts in spite of what the owners manual says.

for example I have 3 identical old mercedes with the same engine. They have a capacity of slightly less than 8 qts, and when I put that amount of oil in they are at max on the dipstick.

This mazda would take like 5.5 qts to read full on the dipstick; like 1.5 quarts more than the specification. I Just want to know if there is any reason the capacity is really 5.5 qts. I

[Lorrin Barth]

Yeah, most curious, having the dipstick always read low would bother me. If this was my car I’d venture the 10-20 bux it would take to get another dip stick from the dealer just to see if they would match.

[Jonathan Stiver]

It’s been several years since I sold my Milly, but I distinctly remember using slightly more than 4 qts for oil changes, maybe as much as 4.5. But mine was on the original supercharger so of course it burned oil like nobody’s business, so I wonder if that factored in any. I see the Miller cycles in the junkyard all the time, I’ll measure the dipstick for you this weekend if there’s doubt there.

[silveralfa]

This morning I called the dealer that serviced the car before I got it and he measured a dipstick for me which I will compare when the car comes home later today. I now expect my dipstick to be correct.

He also checked with his master techs that have 20 and25 years on these cars. They were surprised the spec is 4 quarts as they always use a little less than 6 quarts on an oil change. How about that? I’m thinking now the dipstick is right and the spec is wrong.

Thanks for helping me think this through. I will follow up when I compare the measurements

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