Oil Question
 

2006 Shinka, 92000mi

After a few oil changes I noticed that my oil levels were always full. I do add 1 quart around 1,500 miles into the oil change cycle but it never stumped me that my car wasn't consuming a lot.

I have no issues with the Shinka, compression is great, clutch still engages fully, and I have never overheated or went over on oil pressure. Prettt much healthy as a brand new car.

Last week I was over my oil change miles by 120 and decided to add a quart before a long drive and then getting the oil changed the next day. This time I did NOT add a quart mid cycle. On the trip I noticed first gear was stuttering and when I picked up RPMs past 5.5k the car would struggle and blow white smoke. I immediately pulled over and checked the forums for symptoms. I then cleaned out my Aem intake, and MAF. The car ran fine after.

So my question, is there something that I need to worry about if I'm not cunsuming as much oil as the car is pronounced to consume?

Don't blindly add oil, Use your dip stick.

Do you know if your filler neck hose connects to the intake tube? If it does do you use a long funnel to fill your oil?

The car consumes oil based on load. If you don't drive it hard it will not use a lot of oil. I drive very hard (redline multiple times every time I drive it)and use about 1 quart every 1500 miles.

That makes a lot of sense, thank you. I do use a long funnel to add oil. I checked the dip stick that morning, however I do remember getting in late that night, so the car probably wasnt fully settled.

I do not drive hard at all. I redline about once every few days, I hardly drive in the city and keep at a cruised 64mph on the freeway.

Thank you for the help!

Drive it like you stole it!
:)

You need to redline every day (once engine is fully warmed) This helps keep carbon from building up inside the engine. Babying this car is a prescription for engine problems and declining performance as it will surely lead to carbon buildup which can lead to engine seal problems , blow by and reduced compression. please read thoroughly https://www.rx8club.com/new-member-f...t-here-202454/

Always check the oil with car on level surface, be sure the car is properly warmed up then shut off the engine and wait five minutes for the oil to settle for a proper measurement with the dipstick. When you are not putting load on the engine, it will not use as much oil.

Rotary engines are the healthiest and last the longest when properly exercised , as well as properly maintained. . I know, I have owned seven rotary cars since 1973 with over a million rotary miles on street and track.

I'm not recomending it, take your own risks, but I just add a quart when the low oil light comes on. until then I just don't worry about it.

I'm not sure that's a good idea. I was under the impression that the oil injection aids in cooling, so it would seem to me less oil would get hotter, but I don't know for sure.
I've seen a lot of recommendations for adding oil at the halfway point of the dipstick, keeping it on the full side.

Yeah and I have no knowledge of oil temps with that.

At the same time, on the stock map if you keep it below 40 pct Load and 4000 RPM then you are only using 3(most of the time) to 7 Steps on the oil injection rate.

Above 5000 RPM to full throttle you get 27-60 Steps of oil injection. That could be up to 20 times the amount of oil. With a lot of hard driving, the additional oil should make up for any additional heat.

I believe the oil light comes on when the level is at or below the bottom mark onthe dipstick. That's two quarts down. If you just add a quart when that happens, you're always one to two quarts down. Best to use the dipstick, and add a quart when it's a quart down. The owner's manual (for whatever that's worth) recommends keeping the oil level near full.

Has anyone other than me checked oil when cold, and then after warmup and being shut down for five minutes, and discovered that it comes out the same? I've calculated how much it expands when hot, but never see that difference in real life. The oil pan must expand by the same volume when hot.

The important part of the manual's instruction is to wait five minutes after shutdown so the oil gets to drain to the bottom. Otherwise you're likely to overfill.

Ken

Thermodynamically speaking smaller volumes expel heat (and absorb heat) quicker. It's the surface area to volume ratio. So while a smaller sump supply will warm up quicker, it will also cool quicker.

That is, of course, ignoring the giant oil coolers on either side of the front bumper... and of course, no sump temperature will ever be as hot as the combustion chamber of a rotary. No matter what your oil is doing, it's always going to be injected at a cooler temperature than the apex seal and rotor face.

Never let your oil get so low as the oil light comes on, check your oil every other gas fill up and keep it at the top level (don't overfill or you can get oil in the intake) Your oil is helping cool your engine so don't risk hurting your engine by being lazy with keeping the oil level properly full. Remember almost half your oil is in the oil coolers which are designed to remove engine heat, so it is important to keep your oil level correct. Your method will surely lead to an earlier demise of your engine. I have owned seven rotary cars since 1973 and have seen many a dead rotary engine from folks not keeping up with proper oil levels. It is a cheap and easy thing to do for the health and longevity of your engine.

Do you Premix? If yes....also heavy Premix may cause the "optical impression" that you consume less 4-stroke oil from the sump......(experience of many Premixers on the German RX-8-forum, incl. myself)

Put a Sohn adapter on and switch the crankcase to full synthetic and run 2 cycle in a separate tank for the oil injection. And you need to run the piss out of it after its warm every time u drive it..

138K miles before I blew a water gasket. I never changed coils(still stock from 2005 at 138K). I changed plugs and wires every 30K. I ran for over 70K miles without the Undertray. And never had the coolent system flushed or worked on at all. I shift when I hear it beep and do that every chance I can get. While driving it in 110 Degree dry texas heat. My wife Daily drove it in stop and go Ft worth traffic.

Yeah without a doubt heat killed it, but it took a lot of neglect and ran a lot longer then most engines I see. Some people are on their 4th engine by that time.

Now things are a little different for me, I only drive it about 1500 miles a year(just short drives to the grocery store, DR's office,or skate park really. I'm almost never in traffic, have a shon, Run full synthetic, have a custom sheet metal undertray, I've also added a real temp gauge for oil, and water. Midpipe, and d585 coils with accel 8.8 MM 25 ohm wires.

It would seem you are proud of how you neglected your maintenance which of course shortened the life of your engine. Hey i have owned seven rotary cars, stock and modified for street and track over 41 years since 1973. Easily over a million rotary miles , street and track and NEVER one single rotary engine failure, NEVER ! I drive them hard, but also take care of my cars and rotary engines and they last like iron. It is no badge of honor to have gone through multiple engines, just a sign of neglect. And yes I have always premixed.

No it's not proud, I'm not afraid to admit to my stupidity either. If we don't learn from our mistakes and others then we'll never advance. I'm just kind of amazed of how people preach so many things go bad on these cars and they are normally the ones that are replacing engines every 30K miles.

The undertray was just because I didn't have the money or knowledge that it needed to be changed. All the maintance up to 100K was souposed to be done by mazda when I took it in for oil changes, but they never did anything other then plugs and wires.

I do think it lasted a lot longer because I run it hard so It kept extra oil being injected and helps to keep it from building up carbon.

Most of the times I check the oil level when car is cold. I have also noticed that the difference of the oil level when hot/cold is non-significant. You just need to give some room to the oil for it to expand when it gets hot...

Did you premix all those rotaries?
If so, at what rate generally?
Your reply is much appreciated.

Best regards, Ruud

Rudd, yes I premixed all those engine. first with Amsoil, especially in the track-modified RX7s . http://www.amsoil.com/shop/by-produc...?code=TDRQT-EA (back in the day they made a two-stroke synthetic for premixing in rotaries for us track folk, now this seems to be the newer version of that)

With my RX8 I am using Pettit Racing's Protek-R.
http://shop.pettitracing.com/protek-...-p-120049.html For Protek-r you need to use 4 oz per tankful for normally spirited driving, and use more for track days.

Idemitsu http://www.idemitsu-usa.com/h/38/premix.htm is one of the most popular brands of rotary premix and you use 8oz per tankful, more for racing. (these figures are for the series 1 tank) the series 2 tanks are one gallon larger.

And yes I truthfully have never had a rotary engine failure in over a million rotary miles. Some here say I was just lucky. Come on, 41 years of just being lucky ? I think it has a lot to do with how you run and maintain these engines.

I have owned an RX3 (coupe); two RX4's (both coupe and sedan); First Gen RX7-later modified to 400+hp with a Racing Beat built special turbocharged 13b engine; Second Gen. Rx7 Turbo II-later race modified; Third gen. RX7 FD twin-turbo, slight mods; and 2008 40th Anniversary RX8 with Mazdaspeed CAI and BHR ignition. Also owned a 2008 Mazdaspeed3 GT with Mazdaspeed CAI.

It has been 41 years of miles and smiles. I hope to buy the next RX while keeping my RX8 which is great fun every day, and the most refined of all my RXs, even though not the fastest, but still plenty fast enough.

Hi gwilliams6,

Thank you very much for your comprehensive reply; it is very informative!
Indeed it is impressive all those successive rotaries without any failure; I believe too that you were not "just lucky", I think that premixing all those cars was one of the positive factors.
Your information and experience is an encouragement to remain premixing my 231hp RX-8.

Best regards, Ruud

Gwilliams
I use AMsoil sabre pro to premix and also run it in my oil tank (sohn adapter installed). I generally premix 8oz for four full tanks of fuel and then fill it up on the fifth tank from 1/2 with just gas so i even everything out. Please give me your opinion on what I'm doin and how you would do it different.

I keep my coils and plugs in good shape and my cat is gutted. Car runs excellent and i want to keep it that way. Current mileage is around 88,000.
Thanx shane

Shane , AMSOIL SABER® Professional Synthetic 2-Stroke Oil

this looks like what we used back in the eighties and early nineties for premix in our track RX7s. Amsoil makes great stuff and if you are happy with it keep using it for premix. Looks like 8oz per tankful of gas is a good start for premix. that is a 128:1 ratio

I am not sure I would also use it though as my main engine oil. If you are sticking with the Amsoil for your engine oil I would use one of the their signature series oils that have a blend made for rotary engine use. AMSOIL Synthetic Motor Oil and Engine Oil

The advice here is just to break-in any new rotary engine with dino oil before switching to synthetic. And depending on your area, synthetic oil use in your RX8 might cause a problem with Mazda for any engine replacement under warranty. Although you could fight that if need be. In Europe and elsewhere synthetic oil use is actually supported by Mazda, and they have a Mazda-branded synthetic oil available. For that warranty reason I am using Castrol Dino oil in my RX8. My regional Mazda service rep. has (unofficially) advised me to stay with the dino oil. The regional reps are who would have to ok any Mazda warranty engine replacement, but I don't expect to need one if I take care of this engine like my past rotaries. Just being prepared.

Keep your ignition in perfect shape, rotaries are very sensitive to ignition problems. I recommend the BHR coils and wires. They should last the lifetime of your RX8 and offer a stronger spark for better combustion and performance. Change those plugs every 15,000 miles or sooner, depending on how heavy you use them. The NGKs are great. I have changed to the Racing Nippon Denso plugs on advice of one of the longtime RX8 club moderators from Australia (a former Mazda mechanic ,longtime RX owner , now owning both an RX8 and MX5.) . http://www.globaldenso.com/en/produc...cing/spec.html

Both the NGKs and Racing Nippon Denso plugs are readily available from most national auto store chains, much cheaper than from any dealership. . As free an exhaust as possible is always great for a rotary.Here you have lots of choices from Racing Beat, BHR and others. In New Jersey where I now live I couldn't pass emissions without the cat, but the race-modified RX7s had catless exhausts ( I actually changed to a cat for inspections when I lived in NY and Pa. )

Change your oil religiously every 3000 miles, or sooner if you are racing. Though technically the synthetics can last longer. Remember in an RX8 you are only draining half the oil in any regular oil change, the rest stays in the oil coolers, so you want to keep as much new oil recycling through your complete oil system as often as possible. Keep your cooling system in top shape always and flush it and change it out every 30-50,000 miles. The Mazda coolant is actually best here.

@ gwilliams6,
Hi,
I shared your post #19 / experience with the German RX-8-forum.
Best regards, Ruud

Premix ist angefangen! - Seite 49 - Motor - RX-8 Fan-Forum

Ruud, Glad to share my experiences here. Since Mazda rotaries entered my life back in 1973 I have never regretted my love affair with them. (more than I can say for some ladies I have known) lol

The same for me!
Ruud