Oil Contamination in NS CDi's

[Hopperoo]

Hi All,

Can anyone enlighten me as to why it is apparently necessary (according to Mitsubishi) for an oil / filter change after a "forced regeneration burnoff"?

My guess is it's a similar situaion as, years ago in carby petrol cars if the fuel mixture was WAY too rich, unburnt fuel would find it's way into the oil, breaking down the oil lubricating qualities and requiring an oil change!

I read between the lines that perhaps the burnoff excessively richens the fuel / diesel mix, to raise the temperature sufficiently, to the point that Mitsu believe the oil will be broken down to an unacceptable ratio.

IF this is the case, then on normal running when an automatic burnoff is done, won't this be doing a similar thing to a lesser degree? If so, the new "FIX" (which apparently does the burnoff more often) will be contaminating the oil more frequently and requiring more frequent oil changes!! At the price of these new oils for the auto's I'm wondering if Mitsu realise this and are reluctant to raise the topic with the owners.

[matthewfnorbert]

just because the ecu has been modified to better manage the dpf, does not mean that more build up is present in the dpf requiring more burn off's, rather i am guessing they will happen more often (for less time) to burn the same amount of particulate build up.. the ecu would decide when the dpf is "clean" and should burn off in total time about the same as before??

my concern would be does the large amounts (relative) of fuel used to raise temp wash the bores? my oil analysis will reveal this, to date no fuel seen in oil at 15,000km

[Eastie]

I asked the service manager about the fix and the main points he outlined were:

• there is (according to him) a lot of mis-information about what the fix actually does
• the original problem was related to our fuel - the ecu was programmed for <10ppm diesel.
• although running >10ppm fuel has caused most of the DPF/Check Engine situations, the original ecu program doesn't just rely upon "actual" PM in the filter or exhaust back-pressure alone to determine the state of the system. It uses numerous sensors and "guestimates" when the filter should be regenerated (this is similar to what the service/build manuals indicate).

He could not explain how/why this "suposed fix" would reduce PM buildup on the filter, why it would not do more dpf regenereation burns now it's programmed for crap diesel and he wouldn't accept that this could possibly have an affect on the life of the filter and thus the future service costs.

Anyhow, now that mine has had the 'supposed fix' I've done 700km and I'm not impressed. Km per tank is way down, and the engine has died twice to below 1000rpm when accelerating from ligths with the aircon going - it neverr did this before but did it straight aftere "the so called fix".

I'll be calling MMA customer line on Monday to register yet another vehicle fault.

[matthewfnorbert]

eastie sounds like a sensor issue somewhere? did you get a service done at the same time? if so check the air filter is on correctly/air mass flow sensor plugged in all the way etc...

i love how the dealer can't tell you what the problems are but when you suggest something they can tell you with confidence what it is not, when it suits them

[MinniTheMoocha]

eastie sounds like a sensor issue somewhere? did you get a service done at the same time? if so check the air filter is on correctly/air mass flow sensor plugged in all the way etc...

i love how the dealer can't tell you what the problems are but when you suggest something they can tell you with confidence what it is not, when it suits them

You are damn right about this. It is really annoying me with the service department of my dealer as they have been doing this since I got the car.

[Hopperoo]

I believe I'm on the right track with this diesel contamination "problem", as it was stated on another thread that the dealerships are admitting they only change the oil / filter (after a forced regeneration) in vehicles that display a higher than normal oil level!! This obviously is indicative of raw diesel finding it's way into the oil sump while the regeneration is being performed.

So, what happens to the vehicles that have some minor diesel contamination, but not enough to ring alarm bells? Perhaps reduced engine / bearing life in future. If so, will Mitsubishi extend the engine warranty for rapid wear etc?

Pickle, I would be interested in hearing "officially" their response.

[keefymonster]

I checked my oil level after the ecu update.
The oil was as black as the ace of spades and higher up the dip stick.
It doesn't say anything on the service receipt about an oil change.
I bet they didn't even check the oil.
I wouldn't be at all suprised if the oil is contaminated with diesel.
I should get it analysed.
I really do not trust my local service dept.

Keef

[keefymonster]

Here is some interesting stuff about oil analyses.
It mentions diesel contamination....

http://www.oilsols.com/oil_analysis/tests.html


Keef

[Pickle]

So, what happens to the vehicles that have some minor diesel contamination, but not enough to ring alarm bells? Perhaps reduced engine / bearing life in future. If so, will Mitsubishi extend the engine warranty for rapid wear etc?

Pickle, I would be interested in hearing "officially" their response.

I can tell you now there would be no official response! The 4M41 has a 10 year warranty on it now. Think about it, so you wan't maybe a couple of more years warranty because it may or may not have been contaminated with deisel. I very much doubt it will happen.
Dave