mazda deisel oil change

[mickcoulson]

hi..my son has a mazda deisel car and his oil warning light has lit up. when he checked the oil the dipstick which had a low/ normal and x marked on it was on the x mark ( too much oil )when he enquired he was told that he had not done enough milage and diesel had been added to the engine oil and required an oil change...now i'm not the brightest of persons but that to me that sounds a bit odd, why can't he just drain a bit of oil out to the normal level
cheers
mickcoulson

 

[Burnerman]

I'm not too sure about whats been going on here Mick, but if the engine oil is contaminated with diesel, then it must be changed.
How did the diesel get there - do you know?
John

 

[Peter.N.]

I would agree with John. The oil change intervals of many modern cars are far to long anyway and I am sure that this is the cause of many engine failures, for safety and reliability it needs changing every 6000 miles or so.

Peter

 

[xfr]

Its hit the x mark because the dpf has failed to regenerate,and has dumped diesel in to the sump.This must be drained immediately along with a new oil filter,is it a 2.0 or 2.2 id guess its a 2.0 as they are more problematic..

 

[AlanE]

How did the diesel get there - do you know?
John

Leaking fuel injector?

 

[mickcoulson]

hi john.. from what the garage ( mazda dealer ) told my son this is normal for a diesel engine, if he is doing low milage then diesel is added to the engine oil ( sounds stupid to me ) unless my son has not understood correctly
mick

 

[mickcoulson]

Its hit the x mark because the dpf has failed to regenerate,and has dumped diesel in to the sump.This must be drained immediately along with a new oil filter,is it a 2.0 or 2.2 id guess its a 2.0 as they are more problematic..

thanks that seems like the most reasonable explanation, my son has been told low mileage can cause this problem
mick

 

[mickcoulson]

hi john.. from what the garage ( mazda dealer ) told my son this is normal for a diesel engine, if he is doing low milage then diesel is added to the engine oil ( sounds stupid to me ) unless my son has not understood correctly
mick

THANKS EVERYBODY FOR YOUR QUICK RESPONSE AND INFO.
MICK

 

[Burnerman]

hi john.. from what the garage ( mazda dealer ) told my son this is normal for a diesel engine, if he is doing low milage then diesel is added to the engine oil ( sounds stupid to me ) unless my son has not understood correctly
mick

Hell please tell me someone that I am not completely losing the plot.....
DPF's failing to regenerate is reasonably common - cured by a good long run at high temperatures.
Diesel oil doesn't have anywhere near the lubricity properties of a 10/30 fully synthetic and there's no way anyone would be putting that in my motor.
I do appreciate though that DPF engines do need a specific oil specification to protect them, and that should be used at all times.
Lets know what transpires, Mick!
John

 

[Burnerman]

Its hit the x mark because the dpf has failed to regenerate,and has dumped diesel in to the sump.This must be drained immediately along with a new oil filter,is it a 2.0 or 2.2 id guess its a 2.0 as they are more problematic..

How does diesel get dumped into the sump?
I can appreciate that certain cylinder head designs (Isuzu in particular) can allow high pressure diesel to escape into the coolant, but I've never heard of it leaking into the sump.
John

 

[xfr]

It doesn't leak.it goes there after a failed dpf regeneration
thats why you must use a c1 or jaso dl-1 spec oil.
its a Mazda design to clean the dpf using diesel.

 

[Burnerman]

It doesn't leak.it goes there after a failed dpf regeneration
thats why you must use a c1 or jaso dl-1 spec oil.
its a Mazda design to clean the dpf using diesel.

Thanks for that So what happens? Is diesel injected into the engine oil directly or straight into the DPF? All new to me, this!
John

 

[alan333]

xfr is correct. There's plenty info about the issue on the Mazda forums. The engine oil is now diluted with diesel and must be changed along with the oil filter. Also the light needs reset, supposedly only by Mazda, and IIRC there was some reason why it couldn't be left with the light on. Can't remember why tho. I almost bought a Mazda 6 2.0 diesel until I found this out.

BTW on some cars you can tell when the regeneration process is happening (I think it was Citroen that the rear demistor and heated mirrors came on themselves, for example), so it might be worth a browse around a Mazda forum for more info, maybe not switching the car off during regen stops the problem? Sorry I can't properly temember the info, but it wasn't too hard to find it.

 

[Burnerman]

Just for engineering interest I'll certainly check it out......seems potty to me!
Imagine a steaming hot turbo getting fed with inferior lubricant.......
Imagine the sump level getting so high that the engine decides to feed on its own lubricant, and revs until it self destructs
(Seen that once - Nissan X Trail......pays to keep your head well down
John

 

[Mursal]

That's the second time today, I've been told that its to clean the DPF and not leaking into the sump via an injector seal failure in the head, which I find more logical.
Seemingly the engine fuel itself heavily while altering the injection timing to clean the Diesel Particulate Filter in the exhaust???? But instead it washed past the rings, on the Isuzu 2.5 in the D-Max.
But surely the pistons would seize if that amount of fuel was passing the rings?

Diluting engine oil with diesel, talk about living on the edge .........