Oh, and 'UNIT TYPE' is also incorrect. The stock tune only makes it APPEAR to have a diesel engine. It's an ILLUSION.

 

Sub, Sometimes misery loves company so I was "happy" to hear that the EVO X is not alone when it comes to fuel dilution, ... even Bimmers! Noize are you listening? I am beginning to think this problem is endemic to aluminum engines in warm up; still just speculation, of course.
Now one question: I note that you changed injectors on your Suby and that the fuel dilution went down. Did you do this on a hunch or was there any signs that the injectors were not operating correctly? If the answer is yes to the latter, what specific test/measure was performed? Thanks for your reply.

Later, Ken

 

Thanks guys for posting analysis. It's looking like we definitely have a trend here.

I know there's been a lot of internet speculation (I'm guilty of it, as well) into the cause of this, but I had another question I've not seen a definitive answer to: If I change my oil every 1000-1500 miles to keep oil dilution (somewhat) under control, will my engine be ok? Changing my oil's not so bad, and I don't mind doing it 2x as often if it means I'll save my motor. Sure, the $30 I spend on Pennzoil Platinum and a filter isn't cheap, but compared to a new/rebuilt 4b11... I'll spend the $30.

 

Yes Burt, changing the oil more frequently, albeit more expensive, is a good stop-gap approach that some are using (STI2EVO for example). That said, we need to ID the cause(s) so that a long term solution can be implimented, assuming it is feasible.

Later, Ken

 

FWIW, I had my oil changed the first time today at around 4k miles. Stock tune and no engine mods. I mentioned that my oil smelled strongly of gas, and the service advisor agreed that this was "bad".

He mentioned that there had been some correspondence from Mitsubishi about this issue, and advised me that he would like me to come back in 500 miles so that they can "look things over". He said if the problem persists, he'd like to check the fuel injectors, etc. and try to figure out what's wrong. I'm pleasantly surprised that he seems willing to take the initiative to figure out what's wrong, but it makes me a little nervous at the same time since nobody else's dealer seems to be offering to help...

I will let everyone know what we find out.

BTW, is there a consensus on whether this problem can be rectified (at least somewhat) by leaning out the AFR? In other words, do we know yet if an AccessPort or other tune help at all?

 

^Well, one guy who has a custom tune by dynoflash did an analysis and still had insane fuel dilution that was no better than the rest of our results on the stock tune, so that doesn't look good. I am leaning more and more towards the engine warm up theory that Ken has. It would seem feasible to me, although I never dog my car until it's been driven for at LEAST 10-15 min, and if an engine isn't warm by then then how long could it possibly take? Perhaps that's not the cause, and the real culprt is still undiscovered. Who knows, but there aren't that many things that it could be, so we'll just keep narrowing things down until we figure something out. In the meantime, I'm just gonna keep changing my oil at 2k and will hope for better oil analysis results next time, since I'm tuned now. We'll see, I suppose.

 

Bummer.

I was hoping I could use this as an excuse to get an AccessPort sooner than I've been "authorized" to by my wife, but since it hasn't been ruled out I think I'll give it a shot anyway. Along with the fact that she wants to get her GR STI tuned for fear that her engine will detonate, this might just work out in my favor after all.

Glad you guys started and maintain this thread - hopefully we'll get some more concrete answers soon.

Oh, and my number 1 rule is to always let the car warm up before getting on it (at least 5-10 minutes) and I still had the gas smell...

 

Is anyone that has verified the excessive dilution issue considering court action? I feel like this issue is substantially impairing the value of my car (not to mention the notchy shifter) and could likely cause premature engine wear/failure.

I know this is early in the game as far as what we are dealing with, and oil analysis reports are still coming in, but I'm coming up on 1 year of ownership. The lemon law protection in my state is only in the first year or 18,000 miles, whichever occurs first. I have about 3 weeks before the one year is up, so I don't have time to get another oil change and analysis.

So I either file, or sit tight and hope that we discover a fix or Mitsu take ownership of the problem. If neither occurs, then I'm out of luck and stuck with it.

What do you guys think?

 

I was experiencing idle misfire, especially bad during warmup. I tried to get the injectors replaced under warranty, but the service department's dumb Diagnostic Computer showed no misfires. And my CEL never came on. But I could clearly hear and feel the misfires, and there was a lot more misfiring than when the car was brand new. I showed them my UOA history, but Subaru of America customer service informed me they do not take warranty action based on "outside data".

There was some internet chatter about the injectors on '05 Legacys having a high failure rate. So I replaced one injector at my expense, and heard a reduction in idle misfiring. After that I replaced the other 3 injectors, and had a further reduction of misfires. And I started using a fuel additive called FP Plus to keep the injectors clean and lubricated.

http://www.lcdinc.com/products_fuel_power.php

Two years later, in the '07 model year, Subaru changed the injector and fuel rail design, going from the original (and problematic) side feed injector to a top feed injector. But of course there was never an admission from Subaru that the side feed injectors were problematic.

 

Most state's lemon laws require a particular item to be persistent through 3 fixes by the dealership. I don't know your situation, but at least here if you haven't had your car in 3 times without resolution or recurrence than you're not eligible for a lemon law replacement anyway.

If you're considering it, I think you need to get it to the documented by the dealer ASAP.

 

Here is a UOA on a twin turbo BMW, with 1000 miles on M1 0W40. They refer to it as a "fuel diluting monster" because it had fuel up to 2.26%. But that is half of what some of you are seeing with the EVO X !

http://www.bobistheoilguy.com/forums...rue#Post986378

 

If this issue was as much of a problem as people make it out to be, I don't see how anyone could make it past 15k miles (especially the way most of us drive) without having severe engine issues.

I'd be confident saying that Mitsubishi is well aware of their fuel/oil ratio, and have recommended a specific oil viscosity that still leaves the car in a safe operating state. I'd be less confident saying that Mitsubishi has performed no oil analysis on their high performance line of vehicles.

Of course that argument loses weight when we consider things like after-sale ECU flashes. Even though people are reporting abnormally high dilution percentages, these tests are still inconclusive.

 

If the dealer refuses to acknowledge or fix the problem, then bringing the car in 3 times is a formality. You're right, I do need to raise the issue though and see what happens.

 

How many here have more than 15k miles? Not many, I'd guess. Even then, you know enough about the metallurgy and structural layout of the engine to say that fuel dilution issues will cause major failures within 15k miles? I doubt it.

The regional engineering lead sounded concerned and asked my dealership to get my oil analysis results when they come in (but would not pay for either the oil change or the analysis under warranty). That doesn't sound like they're "well aware" of the issue, or that they planned ahead with a recommended weight to combat it. Indeed, most comments I've seen elsewhere indicate that Mobil 1 is horrid at handling fuel dilution and should not be used in engines that have such a problem. If they're aware, why recommend it?

They most likely answer is Mitsubishi is learning about the properties of this new engine just as we are. Given their past history with warranties, I think it's silly to just assume it will all be OK. Especially given the results so far show that going the full 5k recommended oil change interval may put you well above critical fuel dilution levels.


You have to compare like to like. We have 4.7% and 4.9% fuel dilution numbers, yes, but they're over 3k+ miles.

Our average dilution per 1k miles so far is 1.58%, well short of that BMW's 2.26%. We did have a 2.29%, though, but the others are much lower. So we may be a little bit better, depending on how other like BMWs tested.

 

nvm, OT.