Oil level increasing.

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Doblegota
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Oil level increasing.

Post by Doblegota »

Hello everybody,

As I have left in my first post I’m from Spain and my car is a Shinka or not exactly a evolve Rx8 copper red.

The car has the sohn adapter installed and here come what I discovered:

The oil from the carter (sump) is increasing!!

Of course the dipstick shows to me that is not a single mililiter. I’m reporting quite a half liter of oil mixed with fuel.

It’s my second oil change. First was when I bought the car without the sohn and started using idemitsu 10w30. In few miles idemitsu became black.

Later I putted the sohn and in the reservoir I putted also idemitsu 10w30. I know perfectly for what is the sohn but I started not mixing oils because there is time in the future to put two stroke oil and another oil in the sump.

With the sohn I discovered that a lot of the fresh oil passing through the nozzles and being burned in the combustion chamber goes to the oil system and I don’t know if it’s only from sideseals or any other part.

There are no smokes, no check engine light, no DTC reported,...
The car is a daily car and never has a bad start, never did Me a missfire,... the car runs hard and strong, reving to the limit in hard driving’s.

I read here a post that some owner who did a renesis airplane with sohn and doing strong premix reported a huge oil increase.

I had to remove oil and now soon will repeat. I do also premix but only 100-120ml per full tank. All is idemitsu.

What’s your opinion people??

Thanks a lot!!

Kind regards.
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Re: Oil level increasing.

Post by PeteH »

We did have an interesting discussion about this. Many people, including me, do not think it is very likely to get oil from the oil injectors to go into the sump when the engine is in good condition. It is not completely impossible, but it seems very unlikely. The oil would have to get past three different seals. If you have some broken seals, or very worn side plates, then possibly some oil will get past.

If you are sure that the oil level is definitely rising, and it's not due to water, then it does mean you might have some engine damage.
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Re: Oil level increasing.

Post by Shagrington »

Did this start happening only after the Sohn adaptor was installed? I don't know anything beyond the basic idea of how the Sohn adaptor works but are you sure it is properly installed - is it oil from the reservoir that you will eventually be putting two stroke into somehow getting into the sump or is it fuel?
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Re: Oil level increasing.

Post by Doblegota »

Thanks for the reply! ;-)

It happens before sohn installation. Te only thing is that is very difficult to notify these problem if you don’t have the sohn adapter. You could feel that oil consumption (in oem system) is lower but also the darkness of the oil with the fuel smell when you check the dipstick.

I saw that an my oil consumption is normally 100ml per 100km before and with sohn adapter.

So, sohn adapter is well installed and there are no leaks.

When I bought the car SSV was knocking and was replaced off a new one. It has also a dw300 fuel pump installed. Oil nozzles are correct.

Everything looks correct and I thing hopefully I putted the sohn with the same oil.
The fresh idemitsu enters with non burned fuel mixing with the other idemitsu being getting dark.
I have to see my compression but is really rare how runs the car, how works daily and no problem! :-(

And I repeat: no smokes, idle fine, ... ¿?

If some one could tell me something would be great.

Cheers!
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Re: Oil level increasing.

Post by warpc0il »

My understanding of the issue...
  • Fuel is getting into the sump, sufficient to raise the oil level, by a factor something less than the level would normally drop through OMP consumption.
    The net effect, before the sohn was fitted was less "oil consumption" than would be expected.
    Since the sohn was fitted there is no oil consumption and therefore the oil level is increasing.
    The sump oil is obviously fuel contaminated.
    The sohn hasn't caused the problem is isn't a factor, other than making the original problem more obvious.
So the question is really, how is fuel finding it's way into the sump? To which there can only be two answers;
- unburnt fuel from the combustion process is finding its way from the combustion chamber into the sump.
- fuel from the fuel rail/injectors is finding a route to the sump before the combustion chamber.

The first process would require either an extremely rich mixture or poor ignition, such that not all the fuel being injected is being burnt, plus side seals that are allowing this excess fuel to pass into the sump.

A rich mixture could be caused by a number of factors, including a contaminated MAF or a faulty IAT sensor.
Poor ignition is a common problem due to failed coils and poor HT leads.
The side seals may be leaking on the exhaust cycle of the rotor and therefore not be detectable by, or have any impact on, a compression test.

The second scenario is a bit more theoretical, as I can't visualise a path that would allow fuel from the rail into the sump, without there being more than one contributory factor, e.g. a cracked injector mount and a damaged injector body - actually, even that would again just make the mixture very rich, since the injectors are mounted in the intake manifold.

Fuel contamination of the sump is common in carburettor-fed piston engines, especially when the float sticks and the fuel control valve doesn't shut off. It's also not uncommon on engines with mechanical fuel pumps, where a seal can fail and allow fuel from the pump to leak into the sump via the drive mechanism (gear/pushrod). However, neither of these mechanisms, or even variations of them, apply to the Renesis.
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Re: Oil level increasing.

Post by warpc0il »

Having thought about this, there is another potential mechanism for an extremely rich mixture reaching the combustion chamber, that doesn't involve the PCM being fooled into delivering too much through the injectors.

There is a route from the fuel tank breather system into the intake manifold via the Evap system and the Purge valve. This route should only be subjected to fuel tank vapour and is used to manage the positive pressure within the tank. However, a component failure could (theoretically) cause liquid fuel to be drawn through this route, when the fuel tank level was high.

Does your aftermarket fuel pump installation still have the pressure bypass valve fitted, such that excess pressure from the pump is released within the tank?
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Re: Oil level increasing.

Post by Delanor »

If it was over fuelling enough to increase the oil level then I would have thought there would be signs of such ie. poor running, poor fuel consumption, black exhaust smoke, black sooty plugs etc whereas that doesn`t seem to be the case an increased oil level can only come from over fuelling, or coolant contamination unless the Sohn reservoir is dropping rapidly.

Get an oil analysis check you can get a kit to do it yourself.

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Re: Oil level increasing.

Post by Doblegota »

Thanks so much peolple.

What is important is that the system works. And works perfectly because y check the oil every day In diferent positions and diferent temperature: from really hot to stone cold since I bought the car.
When it was oem I noticed the quick degradation of the idemitsu and that smell. As everyone knows perfectly not the 100% of the oil burns so where it goes? At the same time part of the fuel mixed in the combustion process doesn’t either totally burn: so where it goes? To the exhaust port? Not possible because there is no single blue or black smoke in any drive conditions. Absolutly clean exhaust.

As said I am using the same idemitsu in both parts and the quite total amount of oil sucked from the reservoir and injected by the nozzles Goes to the sump.

I am notifying these in a paper and soon, as happened to the man with the airplane I will remove AGAIN part of the oil from the sump.

I will do a compression test to see what’s going on here but at the moment I’m in a strange situation seen and removing oil.

For example:

I changed the oil and putted exactly 4 liters.
In the reservoir is 2liters.

Quite a liter used from the reservoir came to the sump. And I know that because each spot from the dipstick to another spot is 0.53Q or 0.5 liters. And that’s what happened. :-(

How many oil was burned?? Quite nothing!!

Crazy.
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Re: Oil level increasing.

Post by PeteH »

As said below, you cannot be sure it is all oil in your sump, unless you get a test done. It could be coolant or fuel. You would notice a one litre drop in coolant, so presumably it's not that, but you will not know if it is fuel unless you get the test done. Fuel mixes very well in sump oil. I know because I had a motorcycle that filled it's sump with fuel, and I didn't realize until an engine bearing failed (fuel turns oil into a really bad lubricator!).

Just a thought. I think the oil injectors are meant to atomise the oil. If your injectors are partly blocked then liquid oil could be going into your combustion chamber. This won't burn as easily, and could eventually force its way past the side seals. I still don't think this is likely, and if it is this then your apex seals won't last very long.

Maybe you've got a hole in your rotor ( :whistle: )
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Re: Oil level increasing.

Post by Doblegota »

Fuel is for sure. Coolant is not because I changed recently and as I said, I check everything all time and everyday. Coolant is in place and the minimum of coolant in the combustion chambers will be seen in the exhaust.

But as I am saying ¿wee is that liter of oil from the reservoir? And why is quite a new liter added in the sump.

For sure could be 80% of non burned oil with 20%of fuel. That’s what I have to discover.

A test análisis is also a good idea.

No one here with sohn adapter who had noticed a increase in the sump
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Re: Oil level increasing.

Post by qwakers »

no, it is not possible for the sohn to cause a oil level increase.
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Re: Oil level increasing.

Post by Doblegota »

Why not?
Sohn blocks the oil way from system to OMP.

Were goes that amount of oil dad feeds the nozzles? And later what happens to that non burned oil?

I had gutted cat and there was no blue and no black smoke. Now I have a 200cpi hi flow cat from japspeed and there is not any strange smoke at any time.

Unburned oil is really visible at the back of the car. I don’t have that.

When I was OEM I saw level decreasing like normal but seeing and smelling like fuel that dark idemitsu with less than 5000km.

In the book http://www.rx8handbuch.de Says in smoke issues if there is fuel odor then is necessary to change oil o directly change the engine.
Can’t imagine changing the engine when I drive it everyday day. :-(
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Re: Oil level increasing.

Post by qwakers »

look at the diagrams. its not possible. your sohn is working correctly, your oil is being contaminated with fuel. you need to find out why you are getting fuel in the oil. ignore the sohn, its not a factor here.
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Re: Oil level increasing.

Post by Doblegota »

That’s correct. Sorry, I didn’t said properly. Sohn is who shows me what’s happening, not the cause.

How can I know from were comes the fuel?

There’s ECT sensor when smells fuel in dipstick or removing engine.

Nobody of you people had any smell in the dipstick?

Kind regards
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Re: Oil level increasing.

Post by PeteH »

Ah. Now we are getting somewhere. If you have fuel in your oil then you need to sort it out urgently. It will destroy your engine very quickly. The only way to get fuel in your oil is to have internal engine damage (broken seals or very damaged housings). Or to have lots of bad flooding. Has it been flooded recently?

No, this is not a common problem.

You need to do some tests. You need a compression test. And you need to test your oil. Until you have done those things no-one will be able to tell you if anything is really wrong.

If you do have internal engine damage then you will need a rebuild, even if you think it is still running well. RX8s will keep running with quite serious damage. Then one day it will simply stop.
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Re: Oil level increasing.

Post by Doblegota »

The first owner had one flood. I changed the fuel pump and it took me a bit of cranking to start the engine. But nothing more.

The car goes fine as you say.

Can Ben any idea to know if there are seals or housings?

Housing o irons also.

I have changed recently the oil. It’s only 500km running.

Thanks to all.
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Re: Oil level increasing.

Post by Doblegota »

Could be also my kind of driving?

Because it’s a daily car with really short stop and go moments. Also it runs like searching dead in long distances and all shifts to the limit.
Temps are constantly observed and never passing 102°C.

I have heard that short distance makes really high waste of fuel.
I have seen my AFR at idle in 15.0 - 14.07. When I run like a crazy idiot drops 11.1 and when I Let the throttle goes to 20.03.
Of course In these cases the oil from the reservoir drops quickly.

Here are my details.

I know that even with these arguments still being that fuel in the sump and that’s not normal as you are saying.

For you Engine is bad and should stop running with it

Correct?

Kind regards.
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Re: Oil level increasing.

Post by boosted »

Use a pelapump or siphon. Suck 150ml of oil out the dipstick transfer to sealed clean container and get analysis done...if it's fuel in there prepare for rebuild. Only other thing to suggest is to decarbon using cataclean. It'll clean any carbon deposits from inside engine..or seafoam treatment see you tube popular in the states...what grade fuel you using?

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Re: Oil level increasing.

Post by Doblegota »

I made a seafoam 10months a go. My fuel is 98octane with 100-120ml idemitsu premix in each full tank.

My oil since I bought it is idemitsu 10w30 Ana also with the sohn adapter still using in bouth tanks idemitsu 10w30

I know the 2t oil for sohn adapter but reporting this issue it would be worst mixing diferent oils.
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Re: Oil level increasing.

Post by PeteH »

Are you putting sump oil in your petrol tank?
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Re: Oil level increasing.

Post by Doblegota »

Oh no!

Idemitsu premix 100 / 120ml In each full tank.

Idemitsu 10w30 In sohn reservoir and in the sump.
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Re: Oil level increasing.

Post by Doblegota »

So do you think my sideseals and control oil rings are off?

:-(
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Re: Oil level increasing.

Post by qwakers »

get a compression test, you'll soon know.
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Re: Oil level increasing.

Post by Doblegota »

Well people, here I am again.

First to say:

Since weeks ago I removed one liter of oil from the sump because it was to high level. The intention was to let the level at 500ml above the low mark from the dipstick (first spot above the low level). At the same time I added 500ml in the reservoir so I could exactly see what’s going on.

Surprisingly i have already consume 1liter of oil from the reservoir and the dipstick stays exactly were i let it weeks ago: 500ml above the low mark.

The car goes perfectly, no problems any time, no problems at idle,... and the most strange thing:

Bad compresion!!

I did the compression test with the proper machine and results are really bad:
Front is 80psi and rear is 60psi at 250rpm.

How it’s possible these thing? With that numbers it should don’t start hot or worse things!

But it doesn’t. The car goes to 245km/h, from 0 to 204km/h (fourth gear limit) is brutal as normal renesis.

I’m supposing that there is something wrong if I fill more or above the half of the dipstick because then starts to increase the oil level.
At the moment I drove 800km consuming 1L of oil and the sump stays in the same level.

Kind regards.
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Re: Oil level increasing.

Post by qwakers »

well i cant say im surprised.

rebuild time im afraid...