Low Oil Pressure?

[Biggles777]

Does anyone know of any correlation between low oil pressure warning and overdue oil change mileage reset?

Got an oil pressure warning on a journey, checked the oil level which was OK but was due for a service and as it was its first year out of warranty a local garage who I always use did the service including a flush and DPF regen. All was well for a week when I got another LOP warning. Took it back to the garage who said they found some metal fragments in the sump. I phoned the dealership who advised not to drive it so I had the AA take the car directly to them. They advised the diagnostics would cost me £250 so I agreed the go ahead. Same day they told me that they could not find anything wrong but had changed the oil. 8 months on more LOP warnings. Took it to the dealership explaining that they had found nothing wrong on the previous visit. A phone call later in the day to say the fault was that the garage who did the service forgot to reset the oil change counter which they have now reset and replaced the oil and oil filter and relieved me of a further £199. When asked why they didn't find this during their previous diagnostics they had no reasonable reason.

Car has only done 40K. I cannot understand what the connection would be between low oil pressure and the oil change counter, I am fearful of another LOP warning looming!

[ROCKETRON]

I don’t know how they found fragments of metal in the sump unless he looked through the oil he drained out, why? If the car has had lots of aborted regens then the extra diesel in the sump can cause low oil pressure but if there is swarf in the sump then the most likely problem is camshaft failure, yours is probably just in the vin range to be susceptible.

[Anchorman]

I get weary of repeating that if the oil is changed, the oil data MUST be reset.  The engine measures viscosity and if the oil is changed without a reset it can’t make the right comparisons.  This is NOT a matter of playing with the trip computer, the test wire under the bonnet needs to be earthed at the time of changing the oil.

[Biggles777]

Hi Anchorman,

Sorry that you are weary of repeating yourself. I am a newbie to the forum so not aware of previous history.

Interesting that the reset has to be performed by the grounding wire, I will bear that in mind. Having a curious mind I would be interested finding out the technology in the engine of measuring the viscosity. Having said that, the oil was new so interesting it could only be a conflict of data, i.e. new oil and excessive trip mileage.

This doesn't exonerate the dealer for not resetting the oil data after they replaced the oil and filter and performed an engine flush.

[Anchorman]

I’ll find a detailed explanation soon but for now, here is the reset procedure.

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[Biggles777]

I’ll find a detailed explanation soon but for now, here is the reset procedure.

OK, thank you. Out of interest if the oil data reset has to be done using the grounding wire what is the purpose of the oil reset using the trip meter switch?

[Anchorman]

I’ll find a detailed explanation soon but for now, here is the reset procedure.

OK, thank you. Out of interest if the oil data reset has to be done using the grounding wire what is the purpose of the oil reset using the trip meter switch?

I’m not sure about that but it is a misconception that zeroing the oil change reminder in the MZD infotainment system is the same as resetting the oil data with the grounding wire. As I’ve not experimented with what that button does, I won’t recommend doing it as once the oil is changed, the only way of synchronising it with the new viscosity is to change it again and these days oil is too expensive to keep throwing it away.

[cx5er]

If the oil data is not reset at the time of changing oil, could this result in a check engine light (CEL) MIL P055F error and oil light on a CX-5 2.2D 2017 model?

Just asking as I have had this issue and noticed that the previous owner had an oil change in May followed by a pressure sensor change in June. 

There is sufficient oil in engine and when I checked under the oil filler cap and I can see oil coming in.

[cx5er]

I have an update.

My car is a 2017 CX5 Skyactive diesel. Mazda have fixed it at a cost of £1600 and the car has been regularly serviced by a Mazda main dealer in the UK. The car has been used for long motorway miles so I am very sad that this has happened.

The problem with the Mazda engine is that the oil strainer blocks up causing P055F and P0524 error codes to come up. These codes cause the red oil pressure and yellow check engine light to come up on the dash.

The cause of the fault is that the strainer was blocked by carbon deposits. The strainer is essentially a filter inside the car, which cannot be replaced without significant dismantling of the oil sump, removal of the oil pump, and dismantling the oil pump to get to the oil strainer. The oil strainer costs just £25 but the labour made up the lion share of the cost. Why would you put a filter in such an inaccessible part of the car? Oil filters, air filters and even cabin filters are easy to get to - so why do this? Why make it so hard to replace a part that is going to get blocked?

This is my first and last Mazda - awful experience. Costly and stressful. Not impressed with Mazda at all.
I cannot recommend a Mazda or a CX5 to anyone; in fact I would urge everyone to avoid buying this car.