Dwain Dwibley

UnknownJinX

You can't do a complete oil change unless you tear the engine down to do so. The best you can do is drain it and whatever is in the oil cooler(s). The oil coolers hold about 1.5 litres of oil(or 0.8 litre for the single one if you have an automatic).

If your intake is caked in oil, I suggest you keep an eye on it. If it keeps blowing oil into the intake, something is wrong with your engine. That, and make sure you use a long-necked funnel when putting new oil in.

Black oil means it's been in the engine for way too long. Forget about what the Owner's Manual says and change it every 5000km max(especially with conventional). I'd also be curious if your oil metering system is properly working. Hopefully, they aren't clogged by old oil.

Loki

iTrader: (1)

Not sure what you mean by capture can, there is no such item on a stock car. You'll want to clean the MAF and change the air filter and clean out the intake. Oil on the MAF will mess with its ability to measure airflow.

Aside from overfilling, oil can be forced into the intake by blow by pressure. Clean it all up and see if it comes back and at what rate. Installing a catch can / air separator can help capture that oil instead of letting it get into the intake. Is that what you were referring to above?

NotAPreppie

The total oil capacity is somewhere around 8.5 L but you can't get to a bunch of it because some of it is in the oil cooler(s), eccentric shaft, pump, filter, etc.

That's why total capacity and change volume are different.

Dwain Dwibley

I have added a shot of the box that I am referring to - Having done some research, I now know it is called the resonance chamber. I have also marked on a diagram where I also found traces of oil.

Also at the bottom of the MAF is a hole leading to another void which also had a lot of old oil in. Unfortunately I am unable to show this until I strip down the engine

Engine runs well until I go hard past 9/10k revs - Engine goes into limp mode for a second or so an then starts running smoothy again. Hopefully it is just a case of getting all of the oil out due to overfill/too quick to fill and oil has gotten into places it should not have.

NotAPreppie

Alright, smeghead...

How much oil are we talking here? Just a residue is no big deal since you're going to get a small amount of oil vapor/mist even on a healthy engine. If you took it off and were able to pour oil out of it then that's a problem. The only way I know of to get that much oil in there is to overfill the oil and have it puke up the breather hoses into the accordion tube.

The other parts you have circled are the VFAD vacuum reservoir and solenoid. Getting a lot of oil down there is odd because it's such a long narrow tube that's connected to the UIM behind the throttle body. Also, the airflow in those parts (if you can call it that) is in the direction away from the solenoid towards the UIM. There should be a check valve between the vacuum chamber and the UIM preventing flow in the opposite direction. So that's weird.

Cleaning these parts is easy. Just remove them and use throttlebody or carb cleaner to rinse them out.

UnknownJinX

The revving past 9k "limp mode" is just the fuel/ignition cut(I am a little fuzzy on which one RX-8 uses). You will also hear a beep before and when it happens. The car will cut it at 9500 RPM.

Every car with EFI with do that when you go past the redline. Be glad no modern cars use carburators, because those will just rev the engine until it falls apart.

Shifting at 9000 RPM is sufficient. Your torque is already quickly dropping after 8500 RPM(where your peak power is).

Oats

If you want to get more old oil out just do multiple changes. You have to drive the car between changes to get the old/new oil to mix.

If for example you can change 1/2 of the oil per change (I'm not sure what the actual percentage is you get out each time but 1/2 is easy for the math).
1st change - 1/2 of the oil is old
2nd change - 1/4 of the oil is old
3rd change - 1/8 of the oil is old
4th change - 1/16 of the oil is old

My sisters car actually calls for the ATF to be changed 3 times in row at 60k, I just change it once every 15k instead though.

UnknownJinX

Not much of an advantage IMO unless your oil is really that bad. Might be worth a shot in OP's case, if they don't want to touch the oil coolers.

As for ATF, I know Hondas usually like the 3 drains and fills treatment. Honda ATs also don't like being forcibly flushed by a machine. It has to be done with the 3 d&f.

Dwain Dwibley

Ok, I think it's terminal for the engine.

I have checked the oil level - got to spot on to the top level indicator after running engine warm and leaving for 2-3 mins to settle then checking again and oil level perfect.

I took the car for an hour run - kept mostly to 5-6k revs for about 40 mins. then started to rev up to 9k. Engine struggle a few times to hold acceleration so eased off. Engine warning light comes on after 55 mins - Sat for 5 mins in service station and checked oil to it not even touching the dip stick.

Topped up with emergency liter of oil and then limped home for the remaining 5 min drive

So where the hell has all of that oil gone - Resonator box is full again so I am definitely getting some coming back through the air filter but the exhaust looks clean with no white smoke - so where has it gone?

Do I need to start stripping engine completely - may be a major task as I am unfamiliar with the Wankel setup.

Dwain Dwibley

O, In regards to the issue of the oil in the VFAD - The check valve was facing the wrong direction!!!

So what does the VFAD do exactly? I have seen some forums where it has been removed completely

Loki

iTrader: (1)

I don't recommend stripping the engine yourself. It requires tools and expertise that doesn't come from working on piston engines.

If oil is filling up your intake, that's a pretty good sign you have excess blowby. Not conclusive, but bad sign. I would get a proper compression test before you start dismantling things.

Steve Dallas

The VFAD is completely optional, as long as you cap the vacuum nipple under the UIM. Its purpose is to quiet the intake under light acceleration and cruising. It opens around 5000 RPM to allow more air flow to the engine under heavy acceleration. There is no benefit to removing it, however, unless noise is a benefit.

It does sound like you need a proper compression test on that engine.

Dwain Dwibley

So, I had a compression test done (Approx figures F - 6, 6 & 6 - R 5, 3 & 5) so its terminal with one of the rear block side seals gone. Looking to do an engine rebuild and will look to remove and strip the engine very soon. I will not know which rebuild kit I need to buy until I confirm what the exact damage is - Some companies supply differing parts to Mazfa OEM and wondering if there is a view on different types of APEX seals etc.

One other small point, the mechanic did state that the SSV actuator bush had worn out, which is one of my knocking noises - does anyone know if there is a part number for this, as all I can find is the complete SSV unit which is expensive.

Thanks
Derek

Loki

iTrader: (1)

Use OEM parts. There is no win in using almost anything else.
The bigger question you will have is which of the big parts (irons, housings) are reusable. That's where it gets expensive. Could be all, could be none. Probably some.

I could be wrong, but I don't think the SSV bushing was sold separately. The SSV was revised at some point in 07 I think, if you do go out and buy a full replacement, get the later part.

NotAPreppie

If you're doing for first rotary rebuild on your own, you have two choices:
Be perfect the first time or do it again in a few thousand miles.

I don't know many people that can do anything perfectly the first time.

My biggest piece of advice (aside from having somebody else do it for you) is to hold off buying anything until after you finish the disassembly. Take it all apart, measure all the tolerances, check for chrome flaking, check for bearing wear, check for housing and iron scoring. After you've done all that and come up with a parts list, THEN make a decision about what to purchase.

A budget rebuild won't last very long. Ask me how I know.
A high mileage engine will probably need more than just seals/springs/bearings. Odds are a housing or two (at US$850/each) among other things.

Also, if you're going to dump this much money and labor into an engine, you should also put some money into preventative maintenance while the engine is out. Clutch, coolant, coolant hoses, radiator, water pump, thermostat, coolant temp sensor, check your oil cooler hard and flexible lines and do rust mitigation/prevention, engine mounts, belts, vacuum hoses, test your oil injectors, test your vacuum solenoids, coils/plugs/wires...

If you do everything the "best practices and procedures" way, you can expect to spend an extra US$1000 on top of any engine work.

Or you could ignore all that stuff and take the risk that your minty fresh engine is damaged by a bad accessory.

Dwain Dwibley

Some very sound advice, I always say, buy cheap = buy twice.

Being ex-REME in the Armed Forces, I should know better that buying the right kit will save me time, money and effort in the long run.

My only issues is having to get all of the general garage equipment that is not commonly used (Engine Hoist, Air Compressors etc, flywheel nut - cannot remember exact size , was it 1" and 1/4" ) but once I have paid the expense it will be used again someday when I look at another project.

Will look to do the engine strip and see what I find. I will keep you posted.

On the SSV front - seems like a huge waste to buy a. complete SSV unit if it is only the bush that is broken. Let me try the local Mazda dealer.

O - Does anyone have a link to a RX8 parts catalogue?

Steve Dallas

Listen to NaP. He knows of what he speaks.

Dwain Dwibley

All good advice there, thanks.

Ok - Next question if I may, once I have the engine out and stripped - Is there a link available so that I can get values to test for tolerances?

NotAPreppie

Foxed.ca - Mazda RX-7 Manuals

Sydo

UnknownJinX

Series 2 manual trans model holds 7.1 litres for the whole system. Auto trans holds about 6.4 litres due to having one fewer oil cooler.

S1 should be similar.

Sydo

Sydo

UnknownJinX

Is yours a 4-port 192 BHP model or 6-port 232 BHP model?

Could be that the 4-port only came with 1 oil cooler.