Hello Pros, I am losing sleep on an issue which I am not sure why happening, in my 2007 Mazda CX-9 check oil light would come up after driving around for 5-10mins.. light will disappear as soon as I accelerate and come on as I take my step off the gas. I have changed oil yesterday and levels are fine.. no noise of anything as well.

Googling the issue point to the oil pressure sensor thing/oil pressure.. dnt know how to diagnose though.

Any help would be appreciated.

 

Well, diagnosing require a volt/ohm meter and also a mechanical oil pressure gauge /tester.
IMHO if you are asking than maybe for "YOU" it would simply be easier to change the senser? If you do make sure you clean the thread area and carefully install the new sensor as not to damage it by over tightening.

 

It is not a check oil alarm. It is a low oil pressure alarm. The oil pump is driven by the engine. It puts out more oil pressure when the engine is running faster. Either the engine is idling too slowly, or the oil pump is worn, or the sensor is defective--but that doesn't seem likely if it goes out when the engine speed is increased. (I'm assuming that you put in oil of the correct viscosity.) Also, depending on where the pressure sensor is in relation to the oil filter, a dirty or defective oil filter may restrict the oil flow.

 

How do you define "the correct oil viscosity"? Anyway .... lol
I hope he didn't use GEAR oil LOL

Oil pressure in an engine is better defined as fluid pressure so even my sarcastic gear oil comment there would still be a fluid pressure to measure regardless of the viscosity which IS NOT THE CONCERN !

I would have more impressed had you said clearance cam bearing because although I do not think that is the OP issues what you described fits that scenario more then your other information. Lets try to keep this OP on a straight path to resolving his problems and not on a treasure hunt of diagnostic paths that are the long way around and may simply be a dead end?
BTW there is a bypass valve in most OIL filter so in the event that they become a flow problem the valve closes or opens depending on the oil filter and bypass the filtering. Also the first post excludes this based on the information!

Perhaps re-re4ading the first post again may have you changing your ideas on a possible resolve?

 

How many miles on the engine? The issue can be several things. You have low pressure at idle and that can be worn bearings inside the engine, a partially plugged oil pickup, a worn oil pump or a faulty sensor. There can be other reasons, but those are the usual ones. The big thing is how many miles on the engine. I'm assuming you put the proper weight oil in the engine.

 

The weight or (correct term) viscosity of the oil as I mentioned would not do what the op is describing. most factory oil pressure sensors are pre set to 4-10 psi or less.

 

Well, a 2007 might have many many miles/km on the engine. If someone put in oil that was too light viscosity, the engine is hot, and the pump has significant wear, the pressure will be low. Low enough to trigger the pressure switch?

Yes, all oil filters have some sort of bypass valve in the filter or the housing assembly. It is necessary to bypass thick cold oil or bypass oil when the filter element is so dirty that the filter media could be ripped and pushed into the engine (disaster!). WIX posts the bypass valve settings, and this one is 16 psid...16 psi lower at the outlet than the inlet, then the bypass opens to protect the engine--dirty oil is better than no oil or better than bits of the filter media inside the engine. But if the filter is badly clogged, and the oil pump worn, and engine parts worn---combination of ingredients. It might be time for a new engine, but check the cheap options first.

 

LOL can I ask what you do for a living....
Lets start with you reading this thread!
What do you do or have done for a living - Mazda Forum - Mazda Enthusiast Forums
I do like the "many,many miles" wording , leaves it safe to post the rest of your comment.

If the MAZDA was that worn you would have seen a couple of DTCs.....it is still an OBDII ECU system.
There is a lot of technical information about motor oils regarding viscosity changes so technically your response might be somewhat a consideration if someone used a 0w (hard to find) motor oil only . You are also implying that a higher viscosity oil be used in engine with higher miles on them, this would be a bad idea if you truly understand how oil viscosity works and might effect a well seasoned engine. At one time we all I am sure thought that as the engine get higher miles you use a HEAVIER(term for that time period ) oil to compensate for the cylinder, ring and valvetrain components as well bearing wearing out and clearance by that wear. Now we know (or most of us) that that was a good idea.

I can't comment on some of the rest of your response because you found it on the internet and you clearly don't have a full understanding what you found and posted relative information about it?

 

OP, what ended up being the issue? I have the same problem going on. It began within a day of my last oil change.

relevant information:
2013 Mazda CX-9
milage 169k

 

First you should start your own thread about your vehicles specific problem. Your vehicle is not likely the same perimeters as the originals OP in this thread. (miles service record, current overall condition etc.)

However, if your oil light came on then you will have at least a pending DTC in their ECU history. Go scan the OBDII diagnostic connector and look for active and pending and permanent DTC then go look at your monitors.
I strongly advise not use a blue tooth scanning device and get and use a professional quality Diagnostic Scanner that can be connected directly to the diagnostic connector.
It is remotely possible that the connector at the oil pressure sensor is not making good connectability and ot you have a failing oil pressure sensor. A DTC in the ECU can give some clue to this or you can just check the oil pressure sensor connection. DO NOT REPLACE the oil pressure sensor until you confirmed it was at fault. Doing so could cause other problems added to the unresolved first problem.


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