'18 Mazda CX5 Oil Pressure Warning Light

My significant other took her brand new car (2018 Mazda CX5-Grand Touring; 20K Miles) to a major dealership to have it routinely serviced (Oil Change + Tires Rotate) and the very next morning, on the very next trip after returning home from the service appointment, when 100 miles away from home (rush hour Interstate & Downtown driving) she gets a ‘Low Oil Pressure’ warning light.

She claims she drove it “…less than a mile…” after noticing the lit oil warning light and after trying to safely pull out of traffic. I couldn’t get a straight answer to the “How often do you normally check your gauges?” question, however, when a car has a ‘heads-up display’ the probable answer is “…a lot less often…” than maybe she should since all ‘relevant’ info is projected on the windshield.

She called me at work, had to download and send her the Mazda ‘Oil Level Checking’ instructions. She needed gloves to handle the dipstick since it was very hot fifteen minutes after shutting the engine off at a rainy 55 Deg. ambient temperature. Several attempts of reading the oil level returned the same “…I can’t see any oil on it!..”

Obviously, her morning business meeting had to be postponed for later in the day, the wait for the AAA tow truck exceeded three hours and the vehicle was towed back to the very dealership where it was serviced the day before. She demanded a loaner, she got it and then she went back to where she was heading in the morning, albeit some six hours later.

I did call the dealership prior to her arrival in the tow truck and let them know about the morning events then I stopped by when getting off work. The Service Manager told me that when they got it off the tow truck and started the engine the oil warning light went off (and stayed off). They said they checked the oil level and apparently it was ‘right on the mark’. When asked “…Then why did the low oil pressure light come on the day after an oil change?..” his answer was “…Probably just a fluke of the system…”

Now maybe that’s just me, an engineer by trade, but their explanation borders snake oil salesmanship. Also, the extreme cleanliness of the undercarriage ‘smells’ of a cover-up.

So, is her ‘baby’ damaged goods, or she should just drive back to the dealership tomorrow morning, drop her loaner off, maybe give them a crooked look and drive her vehicle away like nothing happened? Is it going to run as expected for many years to come?

I just remembered my Grandpa’s observations when we were replacing the crank bearings on his '49 F150 Flathead 8:…" One minute of running without oil pressure is the equivalent wear of 100,000 miles driven with proper oil pressure>…"

Am I just paranoid or we should be looking into replacing the vehicle?

You should register the complaint with the dealer, get a copy in writing. Keep your oil change receipt and tell them if the car has a bearing knock you will be back for a new engine. If they are snowing you and reinstalled the oil pan plug or removed the second oil filter gasket you must keep the paperwork in case the engine locks up.

If she ran it as long as she did with low or no oil pressure, the engine is going to knocking if not now, very soon.

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No, you are not paranoid. They probably messed up, the oil was not put in, super low or the drain plug fell off. They filled it up. Came up with this BS story.
Wait/listen for an engine knock.
Document everything with date/time/names/etc and keep it. for future warranty claim.

The oil pressure warning light is there for a reason. It lets the driver know that no pressure is detected. Not good!

Since this occurred AFTER the dealer had anything to do with the oil, It appears the dealer is trying to weasel out of their screw up.


Did the AAA driver check the oil or inspect underneath? If he did, try to get a statement from him. The dealer is just claiming the oil was full, so you have a battle ahead. Try to document as much as you can.


devils advocate here:

-New oil can be hard to see on a dipstick to the inexperienced eye. toss in that this is new oil in a fairly new engine, and it may just be very clear.

-Not sure about the undercarriage comment. Was the undercarriage of the car dirty when it was picked up after the oil change, and then cleaned now? Again, I wouldn’t expect a 20k undercarriage isn’t going to be all that dirty.m I would expect a dealership to run a car through a car wash with an oil change.

but yes- keep paperwork. Keep receipts. I may even consider going ahead and escalating this to higher up in the Mazda chain, just so they know about it and you can have record of your concerns if something does happen. Engines REALLY don’t like running without oil, so you will know pretty soon if damage was indeed done.

Yes, the car was pretty dirty when the event happened; she took pictures of it when on the tow truck.
When I got to the dealership, several hours after the car was dropped off, the vehicle was spotless top and bottom; took pics of it myself.
Then again, why did the ‘Oil Warning’ light came on the day after the oil was changed? She took pics of the light as soon as she pulled over-ya know, cell service timestamp.
Been around the block several times myself; as a trained engineer, I really don’t believe in coincidences.

The most likely reason is the shop made a mistake, but unlikely events do happen – people win the 5 million to one chance lotto on a routine basis — so the events you describe isn’t enough evidence to make the claim of a dealership mistake. The advice above to document what happened as best you can, and cross your fingers the dealership repair shop is telling the truth. It’s possible they are, so don’t assume by default they aren’t. Faulty oil pressure sender units are reported here from time to time, you can use the forum search feature to see that for yourself. If the dealership is fibbing and all the oil drained out you’ll know soon enough by the weird sounds coming from the engine. In the meantime take 15 minutes to show your partner how to check the oil on their car. Good idea to measure the oil consumption for the next few thousand miles. I had a problem with a dealership shop not telling me the truth years ago. I knew from the evidence somebody there wasn’t being forthright but I could never determine who it was, just that somebody there wasn’t telling the truth.

Offhand, sounds like the dealer has reverted to cover your tracks mode.

An engine failure due to their mistake will not be a factory warrantable problem. It means the dealer will have to eat the thousands of dollars in an engine replacement scenario and they are certainly not going to want to do that.

I wonder what would happen if you dropped in and asked to speak to the tech who botched this? I suspect you would hear “he doesn’t work here anymore”, which translated means he got axed for his mistake.

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she shut it off. you do not say if tow truck operator drove it onto the flatbed. but dealer did start it and oil light went off. i would assume they checked oil before they started it to move it into shop? maybe not. so, all is well.

She drove it “less than a mile” after the oil light came on. That’s more than enough to damage the engine.

An oil pressure lamp will go out at around 3 to 5 PSI of pressure so even a badly damaged engine can extinguish the oil pressure light if it has oil in it. Three to five PSI can turn off the light but even that is not enough to protect an engine.