DigDug

I've been doing some experimentation with oil change frequency over the last 7 months (since the last rebuild), and I'm finding that the oil has degraded significantly by around 1000 miles. This last time, I ran it to about 1250 miles, and the engine was running pretty rough under all conditions. Even at full boost, I could definitely feel the power loss and a lack of consistency in thrust.

I'm running non-synth Castrol GTX 10W30. My car has one factory oil cooler and a Mocal 25-row, so its total capacity is significantly increased with all the plumbing - on a change I'm only able to drain about 4 quarts of it, so maybe it's a problem with dilution (significant quantity of old oil left after a change). I know others have complained of this in the past...

I really start to feel it "drop off" after around 700-800 miles, and it just goes steadily downhill from there. Does anybody else experience this regularly with their FD? Anybody tried anything to address this with any success? I'm just starting to get tired of changing the oil so often, but if I have to, so be it!

kly

i have the same problem but no answer

Les

What has specifically degraded about the oil? I have seen the viscosity fall off(from a SAE 40 to 30 after 1000 miles)and the cleanliness fall off(noticed in a microscopic viewing of an oil sample) but I have not seen the cars performance change and am not sure why it would. I change my oil every 1000 miles and when I add the new oil, I let it flush for 5 minutes and then dump that and add new oil again. Due to all the dead space in the rotors that isn't easily drained and the oil cooler, I find this necessary--and that does not get it clean--just new. One way to get the system clean is to clean it with a high efficiency filter on a bypass loop. Only after doing this for 30 minutes or so, with a flow rate of maybe 1 pt+/minute will the oil get to some reasonable cleanliness. It would be better to do this continually but I haven't gone to that extent yet. My initial oil samples showed a lot of metal, chrome or whatever(in viewing through a microscope), and the spectrometric came back with high lead--usually a bearing--after only 1000 miles. After I did a flush it came back very clean(very few particles)---no ppm levels from testing though.

Improved FD

install a drain valve in line between the two coolers, helps get more of the dirty, fuel diluted oil out of the system every time you change it...very important

I suggest an oil service interval of 1500 miles with Mobil 1 15w-50, because of rapid viscosity loss

I believe synthetics offer superior performance in the extremely demanding conditions a turbocharged rotary is subjected to (with 10% fuel dilution occurring quite rapidly), but I don't think the high dollar synthetics such as Motul or Idemitsu are worth it for such short service intervals

I do run the Idemitsu pre-mix fuel lube, the OMP is a band aid from Mazda

mono4lamar

iTrader: (32)

yes!!! 1500 miles maximum... everyone has their specific oil they like to use. i like 10w40. synthetics would be good if they did not cake up on the rotars yet some argue that its very minute and that it was only a problem with early syn. oils. not sure of the new info on this. best thing to do would be rig the engine to use synthetic oil and inject from its own tank a mineral base oil into the housings. with my new motor i will be doing a premix of 2 stroke oil. theres a good chart to mixing ratios but a good rule is 1oz per gallon its simple to do and is effective. good luck!

Mazda99Nikon

Some of this sounds a little extreme, but I can say with some background experience, that there may be an advantage to running 10W-40. Here's what I found:

My 1983 1st gen ran 10W-40 Penzoil from the day I bought it. It was retired with the original engine that was still running perfectly after 120,000 plus miles. I did a lot of autocrossing and other crazy stuff with it and beat on it frequently. Oil changes were every 5,000 miles

My 1991 2cond gen went through 2 engines with an average of 85,000 miles per engine. I used 10W-30 as was specified in the manual. Oil changes on the first engine were 5,000 miles. About 4,000 miles on the second engine. Oil change frequency didn't seem to matter in the life of the engine.

My1994 3rd gen has been run primarily on Castrol 10W-30. It now has 59,000 miles and is running quite well. Oil changes have been every 2-3,000 miles, but I was always a little bothered by the engine's rough running sound (it sounded like a farm tractor) compared to my 2gen and 3gen. So, about 3,000 miles ago I changed to Castol GTX 10W-40 Start-up (one of the new oils they are marketing) as an experiment. The engine runs a lot smoother, particularly at idle, almost like a new 12A.

I don't see any difference in power, but the engine seems to climb the RPM scale a lot more quietly.

mods:
Custom cold ram air intake
K&N filter
Downpipe
High perfromance light weight clutch

Les

I have not heard any reasons why engine performance would suffer with oil breakdown, other than extreme oil failure and the consequence. And 30 wt vs 40 wt, I don't know why that would help idle smoothness. But with fuel dilution what it is, 40 or 50 weight seems the way to go if you can get it as a 10 or 15-*. 30 wt thins out too easily.

If I can get digital pictures of the metal particles in the oil I will post them, they are an eye opener--especially after such a short period after changing oil. Of course thin oil(read hot and fuel diluted) is a major accelerator to the generation of wear metal particles.

JConn2299

Again, everyone's getting **** about their oil and most engines are dying from coolant seal leaks. How many rotary engines fail, or even degrade significantly, from some oil malady?

I submit that people who claim to be able to tell whether their oil has 500 miles on it or 1,500 miles on it are suffering psychosomatic symptoms. A classic case of the placebo effect.

Change your oil by every 3,000 miles with a good quality oil and worry about more important things. Your coolant and brake fluid is probably in need of a change.

Improved FD

I'd wager there would be a difference in viscosity and % fuel dilution....wanna bet?

Les

You win the bet, it's been proven that the oil gets less viscous and it happens with fuel dilution. I've done the test myself and I wasn't experiencing any psychosomatic systems at the time.

Also aren't there enough areas of concern with this car that oil problems(read metal particles in the oil and lower viscosity) can be responsible for plenty of problems?

Like,

Turbo seal and bearing failure

Oil seal ring failure, both this and the above are a possible cause for the puff of smoke on start up. Something wore out--and replacing the turbo is expensive and the smoke is annoying---and avoidable?.

eventual Shaft failure and main bearing failure(lead has own up in my oil), maybe this doesn't happen as a catastrophic failure early on before other items have killed the engine for the first time, but wear on these components is eventually going to cost someone when they finally need replacement.

Oil pump, maybe robust enough to survive

Or, what is the chance that metal in the oil, injected into the engine for lube, aids in the wear of the apex seal, and anything else in the combustion chamber

Just food for thought.

What else is lubricated in this engine with oil that can wear?

Improved FD

jconn still believes his "pristine" bone stock '95 FD will be reliable if he just doesn't touch it (except for standard maintenance)

but he's in for a rude awkening...these cars are a ticking time bomb, especially stock

DamonB

Bologna.

There ARE some sensible people still walking the earth!

Kento

The people of that northern industrial city in Italia thank you for recognizing them. They might take issue with how you're using it here, though...
Come to think of it....

dgeesaman

iTrader: (7)

Dave

JConn2299

That you could feel in a blind test? $200 says you couldn't. And the bigger question remains........where are the engine failures due to oil? Not many, if any.
Much more likely to be a coolant seal failure. Yet people get so **** about their oil. There's not nearly as much attention to coolant changes.

JConn2299

LOL! 11 years and the bomb still hasn't gone off. I'm getting tired of waiting.

Limpmode

Well, my 94 has 78k and the original engine. I change my oil either when it starts to go over the full mark from dilution, or when I can't remember the last time I changed it. This is about every 3 months or 1500 miles or so(who knows), but I never have felt a power change from simply changing the oil. Maybe its becuase I change it frequently, or maybe you think a Redline sticker and a oil change increase horsepower. I know all the civic guys from my work do.

Julian

iTrader: (14)

sensing a power change from 500 miles of use. hahaha!!!! if anything the oldl diluted oil wil make more power due to less pumping losses

Julian

iTrader: (14)

My engine will die of a predetonation before an oil failure ... Mobil 1 10w-40 or 15w-50 for 34 rotary years

Improved FD

feel what? am I swimming in the stuff? I'm talking about a lab test of viscosity and fuel dilution

$200 says there would be a difference

it's not that simple, more an issue of accelerated wear

and that's fine, but I change my coolant every year....1500 mile oil change intervals are not extreme with this car

Improved FD

how many stock parts have you had to replace on your car, mr. bologna? and how many are just plain poorly engineered? hmmm, I can think of a few!

radiator with plastic end tanks
tiny IC with cheap rubber hoses
kmart engine wiring harness
fire inducing FPD
plastic AST
engine killing pre-cat
stubbornly inflexible ECU
cheap plastic BOV
retarded fuel filter location
junk motor mounts
spongy differential mount bushings
warping brake discs
hoplessly complex and poorly engineered sequential turbo control system
maze of cheap rubber vacuum lines
crackerjack stock turbos
coolant seals

and there are many others, this is what immediately comes to mind

the stock parts on these cars are, for the most part, junk....I'm trying to think of a non-static part I haven't replaced or upgraded, usually out of necessity

yeah....me

Improved FD

it will....how many miles on the car?

dgeesaman

iTrader: (7)

Oh, the IRONY!!!!! LOL Pot calling the kettle black...

Well lets see - who put a gun to your head and made you buy this car? It's not in the Bible, I hope you realize.

Dave

DamonB

I have replaced mine once with another stock one. The first one lasted about 9 years. It cools just fine.

My car spends a lot of time on the track and runs just fine with these parts. I did have the lower hose fail exactly once a few years ago. After more than 10 years I can't fault it.

Any harness asked to survive those underhood temps will have issues after many years.

Maybe replace it every five years or so?

I'll give you that one.

Blame the federal government, not Mazda

It's designed to run the car as it left the factory. There are plenty of modded ECU's available?

Mine is original with 140K on it. Works perfectly fine.

Mazda recommends replacement every 60,000 miles. If you drive the car everyday at 15K miles a years that's a filter replacement once every 4 years. Boo-friggin-hoo.

I have no problem with the stock mounts. The driver side one did fail after 10 years of abuse so it's been replaced.

Same as above. Failed after 10 years and were replaced with stock ones that I'm sure will last another 10 years.

I track and autox my car on race tires a lot. It's brakes are totally stock. I have never warped a disc.

No free lunch. To get the spool performance of sequential turbos you'll have to swallow a pillow every once in a while.

Yes there's a lot, and yes rubber is cheap. Half of that stuff is federally mandated.

The car then and even now has more performance than the far majority of other vehicles. My first turbos lasted over 100K. I think that's perfectly acceptable. Go study how long turbos last on other cars before making a decision.

Those have proven to be a problem on the turbo cars.

You have an extremely high performance vehicle, many of them nearly 15 years old. In that time stuff will wear out or deteriorate and fail. Just because something breaks every 10 years doesn't insist it isn't up to snuff in my book.

Oh wait. I have replaced a starter solenoid and the battery in the past month. what a POS!

JConn2299

LOL! So true, so true. ImprovedFD illustrates the point that if a person is fanatical about one thing, they also tend to be fanatical about other things too. It's some kind of personality quirk. So, like his worldview, he also has an apocalyptic vision of the FD. He's always predicting doom and waiting for it to blow up.
And those cars that have gone over 100,000 miles, and a few even over 200,000 on their original engines? Those must be the AntiChrist cars. "It's the work of the devil, I tell ya!" LOL. It's a hoot watching this mentality at work.