StevX, Is it safe to assume that the reports suggested cause for the "moderate fuel dilution" is not "excessive idling"?
Also, I am a little confused by the terminology used by the testing company when they say "moderate fuel dilution" at 4%. Oil Doc has indicated that anything greater than 2% is severe (see his earlier posts). So apparently greater than 2%, while not good, is not severe. In short, we need to have a consistent definition of what level of fuel is ok and what is not ok. I hope Oil Doc chimes in here. As I found and indicated earlier, I did see a Prius with 2% fuel dilution but most were less than 1%. My point is, it now appears that 2% to 4%, while undesirable, is not critical i.e., stop running the engine and change the oil.

Later, Ken

 

Well, 3 (don't forget about me). Doesn't matter though; mitsu will do nothing about this until engines start failing so we're wasting our breath.

 

Not as far as I'm concerned. After these latest results, I am pissed, really pissed off.

Later, Ken

 

Ken,

The car has not been subjected to excessive idling.

I'm also unclear as to what % of fuel is unacceptable. The lab tech explained that 6% is critical and 4% is abnormally high. I don't know what the treshold is.

 

I have talked to a tech from a lab, and she told me it kind of varies. She said a thing to monitor with that is wear metals to see if the fuel is eating the bearings. That's when is a problem. But i also read in the interweb(not sure if is true) it was either 6% or 8% there's enought fuel that with the heat it will turn into fumes and could cause detonation inside the engine(lower part).

I know some of you guys are concern and maybe upset. But the harsh truth is, that Mitsu might not do anything we have some until engine failures. And we have yet to see that. I have heard of one engine, but it was valve float, and could have been a driver error.

 

Papi, an engine can fail via detonation but with the level of fuel dilution currently measured we are not talking about engine failure, rather the concern is excessive engine wear. These two features are completely different. That said, I spoke to Oil Doc via phone (he is having trouble with the "big boys" getting on EVOM) and it appears from StevX analysis that there is no evidence of engine wear (no metals) but the oil is now a 20 weight rather than the original 30 weight. So if this is correct, then we have some good, albeit small, news from his analysis.

Later, Ken

 

Well, I had similar results. My wear metals were extremely low, but the oil lost viscocity from the fuel dilution and ended up around a 20W. The only real differences were that my nitration was lower, but so was my magnesium (main anti wear additive in oil). Then again, we are running different oils and have different mileage on the oil samples, so I would expect some differences.

 

Stevx, I am trying to figure out if your tune may still be the cause or not. Was it a mail-in tune, or a custom tune? What are your A/F ratios? Mail-ins usually will run much richer for safety reasons since the car cannot be datalogged. Perhaps this is why you are still getting such bad fuel dilution. This is more wishful thinking than anything else, because I am going in for a custom tune tomorrow and hope that I get better results than you did.

 

http://www.usoilcheck.com/oilchek/se...l+dilution.asp Here is a link to another oil analysis lab, and they say that anything in excess of 4% in a 4 stroke engine is considered abnormal. Oil analyzers seems to say the same thing, which is why both my report and stevx's were flagged as "abnormal" and not "critical. It is still unclear as to what the real "critical" level is, because everyone is saying different things. I think no matter what, there is a problem, but the question is, how bad is it really? We need more professional opinions.

 

I might have missed it, but in looking at the posts on this thread, I haven't seen many if any posts from the major tuners and manufacturers of aftermarket parts for the EVO X. I would be alarmed if they were alarmed but they don't seem to be.

 

I would doubt many tuners send their oil out for analysis, and so probably wouldn't know there's an issue until made aware of it. That's part of what this thread is about. If tuners want to chime in, their results and thoughts would be appreciated.

I don't know how many of you who have gotten analysis performed have changed your own oil, but I did mine today. I don't have an air compressor, but those who do might want to consider Oil Doc's suggestion. My brand new oil looks pretty dirty after the change, and was pitch black before the change. I'll probably wait for the analysis to come back and then change it again right away.

I updated the spreadsheet with SteveX's results. Only 2 data points so far. I started to add some calculations so we can get an idea of the scope of the problem. With only 2 data points the calculations aren't useful yet, but I'll keep it updated as results roll in.

I decided to just host it myself so I'm not constantly attaching things, you can find it here:
EvoX-OilDilution.xls

 

So, because AMS hasn't come in here and said, "yes, this is an issue," you think that means it's not? They haven't commented in this thread because they have no reason to, not because they don't think it's an issue. No vendors commented in the transmission/grinding thread either, I guess that means that issue doesn't exist either. I'm sorry, but that's very naive and illogical.

 

STI, my car was custom tuned by DynoFlash. I have my dyno chart at work. I'll post it soon.

 

How about putting in an oil that is one grade heavier?

 

I very nearly did this today, but then decided against it. I figured it will dilute the same, and the oil weight isn't preventing the fuel from leaking in. The main reasoning was that with Mobil 1 being scarce, I could only find 10W-30 at a good price. I had to pay $14 more for 5W-30