Oil degrading after 3000 miles

[JulianJay]

I purchased a Mk5 Mondeo in April 2015 through a main Ford dealership with about 40,000 miles on the clock.  It was serviced at the time of sale and since then I have done approximately 3000 miles.  Just before Christmas the 'service oil soon light' came on.  I could not book it in until this Monday when I was told that the oil was degrading and did need to be replaced.  Apparently low mileage can cause premature degradation.  I was obviously very concerned at this but agreed to the oil change.  As I am retired and not travelling much currently this could presumably happen again.  I still do not quite understand how or why this happened.  Can anyone help ? 

[fiestaecoboostman]

My understanding is that condensation forms in the engine under the valve cover and gets into the oil. When the car and oil is fully up to temp (long after the water is up to temp) then it gets evaporated away and escapes via the crankcase breather. Lots of short trips don't do this and the oil gets more and more contaminated, short trips can indeed be worse for a car than a lot of gentle motorway miles.

[Frembrit]

Has you car not had an oil change since 2015!! I would recommend an oil change every 12 months if you are doing such low mileage. 

My dads was only covering 700-1000 miles a year, but I would still change the oil in his Focus every 12 months.

[unofix]

I'm amazed that coming up to nearly 7 years with out an oil change (regardless of the mileage) that it was still 'oil' in the engine and not some sort of sludge ! 

[Luke4efc]

5 hours ago, JulianJay said:

I still do not quite understand how or why this happened.  Can anyone help

As others have said, you're supposed to change the oil every 10,000 miles (ish), or every year. Whichever comes first.

[isetta]

Obviously I realise this is bad practice. My wife’s previous focus mk1 was owned by us for 8 yrs. we did about 20k miles total in that time. Through laziness I never changed the oil. But it always looked fine, not too black and no sign of condensation, emulsification. Over the years I have found that some cars suffer really badly from white sludge in the rocker box etc and some don’t even if same type of use. I know the wisdom of oil changes but laziness comes into play sometimes. 

[TomsFocus]

I once bought a very low mileage 306 that had just been used for 1 mile to work and back on weekdays for about 5 years.  No servicing in that time.  No service history.  And as I found on the way home, no coolant either.   To this day one of the most reliable cars I ever bought!!  Of course, I serviced immediately but it was a proper bulletproof engine.  1.8 XU Peugeot petrol engine.  No turbo.  No variable timing.  No wet belt.  No DPF.  Really, the oil didn't have much to do at all!  The 2.0 HDi's were similar, although they had a basic turbo you could still easily push them 20k+ without oil changes.  Totally depends on the type of engine as to whether an oil change is really 'necessary' every year.

[TrevorB]

Wow, I can't believe what I am hearing from Julian and Isetta.

What you are doing is one of the worst things one can do to an engine.

Low mileage, short stop start runs etc etc. oil and filter not changed every year like it should be on your vehicles

A police car with 350.000 miles on thew clock would be in better condition than yours if they were stripped for inspection

[JulianJay]

Sorry there is a major problem with my post.  The car is 2015 and was purchased in April 2021.  I have done 3000 miles since then.

[TomsFocus]

6 minutes ago, JulianJay said:

Sorry there is a major problem with my post.  The car is 2015 and was purchased in April 2021.  I have done 3000 miles since then.

Whoops.  Is it a 1.6 TDCI engine?  The extra fuel from frequent failed DPF regens can degrade the oil quickly with short journeys.  

[iantt]

37 minutes ago, JulianJay said:

Sorry there is a major problem with my post.  The car is 2015 and was purchased in April 2021.  I have done 3000 miles since then.

What engine, and was it serviced before you bought it? Probably something as simple as the oil life not been reset at service.  If it is a diesel then not a good idea buying one only doing short low mileage journey. That being said the 2.0 tdci seems ok doing 14 mile journeys to work and back in my Mondeo . 

[JulianJay]

The engine is the 2 litre diesel automatic gearbox.  I cannot speak for the previous owner but I have been retired now for 6 years so my mileage has reduced.  MY previous  car a Mondeo 2010 2 litre Mk 4 automatic did a similar mileage with no apparent degradation .

[iantt]

Unfortunately you can't compare a 2010 with a 2015. Different and more stringent emission regulations. Later cars do dpf regen more frequent diluting the oil esp with short journeys

Just get the car serviced with oil change, get the garage to reset the oil life then carry on in retirement. 

[TomsFocus]

25 minutes ago, iantt said:

Unfortunately you can't compare a 2010 with a 2015. Different and more stringent emission regulations. Later cars do dpf regen more frequent diluting the oil esp with short journeys

Just get the car serviced with oil change, get the garage to reset the oil life then carry on in retirement. 

Does the 2.0 use post-injection as well as the atomiser?  I was thinking atomiser cars would have less oil dilution.

[iantt]

Mk5 Mondeo on my 2.0 tdci doesn't have an atomiser/vapouriser. I thought it did until I looked for it. MK4 2.0 did. There is a variant of Mk5 that does. Think it's the high hp version 204ps 

Dilution would depend on driving style/journeys . The worst is the 1.5tdci .