Wrench/oil change light how does it work?

[Stkid93]

Hey fellas

recently learned that the wrench light on our dash is typically triggered when the car is suggesting an oil change. (This light is not for low oil levels it’s just talking about the oil life)

All I have been able to find so far is that the light is triggered by various sensors in the car, and is not triggered at a certain mileage. The wrench light can come on at different times for different people. I have seen posts about the light coming on at 2000 miles after an oil change, and other posts where the light doesn’t come on after 10k miles without an oil change.

But how exactly does this work? what sensors are used to determine the oil life and how do they know? Unless there some kind of oil viscosity tester or something built into the engine I can’t see how this would work?

 

[XR650R]

My oil light has never come on in 40,000 miles. It never should.

 

[FiestaSTdude]

My wrench light is always on, I’ve tried clearing it but I can’t figure it out. I’ve just accepted it at this point

 

[Capri to ST]

Mine comes on exactly a year after the last oil change when it was reset. At that point I have only done about 3,500 to 4,000 miles, so if mileage or condition of the oil would trigger it, that doesn't happen in my case.I change it once a year since I am doing low mileage.
I know this doesn't answer your question about any possible sensors, but just wanted to give you another piece of information .

 

[XR650R]

This talks about how it works, but it's not super explanatory. Driving conditions and habits are somehow monitored. https://www.ford.com/support/how-to...t-is-the-intelligent-oil-life-monitor-system/

 

[Dialcaliper]

Some complicated algorithm that’s dependent on how you hard you push the engine towards “severe duty” with a lot of factors coming into play to the point that it’s hard to predict when it will come on. (Cold engine, short trips, romping on it a lot, lugging and many more). Additionally, it may also use “engine hours” like industrial and aircraft engines rather than just vehicle mileage, which makes it even harder to correlate with mileage, but I have no way to confirm that.

You can either trust Ford and wait for it to come on before you change oil, ignore it and change at regular mileage intervals or get your oil tested to figure out the interval.

One note is that while just the wrench usually means an oil change, if the wrench AND the oil pressure light come on together, something very bad is happening with low oil pressure and you need to read the OBD error codes and address it asap before driving the car.

the easiest way to reset the wrench is to use your Cobb or Forscan to reset the oil minder (both in diagnostics)

There’s also supposed to be an updownupdownleftright pedal dance but I haven’t tried it.

1.⁠tap the start button WITHOUT any pedals pressed
2.⁠press and hold both brake and gas together
3.⁠the wrench will blink a few time then disappear. once the wrench disappears, the check engine light begins to blink.
4.⁠wait until the check engine light stops blinking
5.⁠press the start button to shut things off
6.⁠now release the gas and brake
7.⁠start the car....wrench gone

 

[Stkid93]

@Dialcaliper @XR650R @FiestaSTdude @Capri to ST

engine hours could make sense.

But it could also make sense if they used the load and cold start explanation the only question being how does the car know what type of oil you put in? Does it assume everyone uses conventional or synthetic or even a blend? Because some synthetics can handle a lot more wear before going bad. Although me personally I would never put conventional oil in a turbo car especially once it’s modified. I assume not many of us use conventional. That brings up another interesting question, do any of you use conventional oil?

I would assume the car is programmed is assume the oil has been replaced with the ford recommended oil. Motor craft (most likely synthetic or at least a blend)

if it’s time or engine hour based. The type of oil doesn’t matter as much, they suggest changing it at least once a year (sometimes every 6 months) so whether you get conventional or synthetic that won’t really change. if the light goes on by using sensors that’s actually very impressive. I have never personally seen that. Every oil light I have seen in other cars is triggered by mileage or if the amount of oil is too low. Like my Mazda speed 3, it would suggest changing the oil after a certain amount of miles. You set it when changing the oil and then it goes off after that amount of miles.

 

[Dpro]

Mine has never come on though the tech at the last oil change did the reset procedure. I have just watched my mileage and usually changed oil at 5k at the latest and sometimes earlier depending on what type of driving I have been doing prior to the change. Basically I don’t think I have ever run it to the factory recommended 7k .

 

[Stkid93]

@Dpro

personally I think the extended oil change intervals are absolutely stupid. And pretty much any decent mechanic will say the same. I saw a video the other day of a customer who brought in a Honda with 20k miles, brand new. And never changed the oil since she got it because she heard about the 15-20k oil change intervals. The mechanic took apart the motor and the amount of slug in that motor for 20,000 miles was unlike anything you have ever seen. The motor needed to be replaced already.

Even if you buy the Mobil 1 annual protection 20,000 mile oil. I still would never even think about going that far. The only oil I would consider going extended intervals with is probably amsoil and even with them I wouldn’t go above 7500. If any of you guys are interested “engineering explained” on YouTube did a video in which he went to mobil 1s testing lab to see how they came up with the 20,000 mile intervals. And he seemed pretty impressed with their testing and how they got to 20k. But I’m still not buying it, he could have easily been paid off to say nice things.

Yes, refineries have gotten much better over the past 50 years and oil is wayyyy better than it used to be. The oil has to do so much more than It did in the 60s-70s. We have to worry about LSPI, downsized engines with small turbos running a ton of boost (as basically everything is turbo these days), fuel dilution, etc.

Personally I change my oil at right around 3k, 5 tops. Granted I live in a city, so I don’t do as much highway driving as some.

 

[Dpro]

@Dpro

personally I think the extended oil change intervals are absolutely stupid. And pretty much any decent mechanic will say the same. I saw a video the other day of a customer who brought in a Honda with 20k miles, brand new. And never changed the oil since she got it because she heard about the 15-20k oil change intervals. The mechanic took apart the motor and the amount of slug in that motor for 20,000 miles was unlike anything you have ever seen. The motor needed to be replaced already.

Even if you buy the Mobil 1 annual protection 20,000 mile oil. I still would never even think about going that far. The only oil I would consider going extended intervals with is probably amsoil and even with them I wouldn’t go above 7500. If any of you guys are interested “engineering explained” on YouTube did a video in which he went to mobil 1s testing lab to see how they came up with the 20,000 mile intervals. And he seemed pretty impressed with their testing and how they got to 20k. But I’m still not buying it, he could have easily been paid off to say nice things.

Yes, refineries have gotten much better over the past 50 years and oil is wayyyy better than it used to be. The oil has to do so much more than It did in the 60s-70s. We have to worry about LSPI, downsized engines with small turbos running a ton of boost (as basically everything is turbo these days), fuel dilution, etc.

Personally I change my oil at right around 3k, 5 tops. Granted I live in a city, so I don’t do as much highway driving as some.

Oil,change intervals are not just about the oil it’s also about the filter. Seriously there are good and bad filters on the market and I do agree the 7500 mile change interval I only ever did was with Amsoil and their filters. Though I do not use dino oil anymore. I am all about full synthetic .I would also say full synthetic is what Ford recommends for our engines anyways. You are preaching to the choir here🤣

 

[Capri to ST]

This has been a helpful discussion, I have a much better understanding of how the oil reminder / wrench light works now. Thanks everybody for chiming in.

 

[pixelzombie]

Ok, so the wrench light is indeed for the oil change. I thought there may have been a code I needed to access somehow.

 

[Stkid93]

@pixelzombie

Yes,

I believe oil is the only reason it will come on, but don’t quote me on that. In any case it is the car recommending an oil change. And based on what I have ready and heard it can come on for a variety of factors such as:

-length of trips/how long you drive the car before the oil reaches operating temp.

- load/how much and how often you romp on it

- if your driving by itself never triggers the light, then the light will automatically come on after 1 year. So if you only drive 1,000 miles a year. The light will come on

- highway driving vs city. If you are doing mostly highway/low load trips your oil will last significantly longer. They said cruising at a set speed on the highway is about 10x easier on the oil than city driving. (Meaning if you drive 100,000 miles of highway driving using cruise control and staying at low load, it would be equivalent of 10,000 of city driving with short trips and not letting the oil get up to temp)

 

[M-Sport fan]

Basically I don’t think I have ever run it to the factory recommended 7k .

Neither have I, but it has been a full YEAR (but only 4500 miles) since my last change, the longest time frame I have ever gone since first owning any car, or changing the oil myself.

I MUST find a secluded, desolate place (with NO cops circulating/patrolling through the area!) to do this, SOON, for my own (OCD ridden) sanity's sake!

 

[rallytaff]

I go around 8,000 miles between changes. Have done it on all my cars using fully synthetic and never run into any problems. City and freeway driving so it gets a good workout every couple of days.

 

[the duke]

It’s based on multiple variables. Engine hours, rpm’s, load, mileage, time. No sensor in the oil actually runs a signal through the oil to gage resistance and thus particulate matter (BMWs and others do).
It’s also shit and often won’t work properly. Lighting up either right after the reset or sometimes not lighting up at all without resets.

Someone on here got ahold of Ford Engineering years ago and they acknowledged it was an issue but weren’t going to devote resources to it. Understandable.

 

[XR650R]

I did the 100/600/2000/5000 thing when I got it. Every 5000 since, with full synthetic. I never got the oil tested, but it still runs like a top.

 

[M-Sport fan]

It’s based on multiple variables. Engine hours, rpm’s, load, mileage, time. No sensor in the oil actually runs a signal through the oil to gage resistance and thus particulate matter (BMWs and others do).
It’s also shit and often won’t work properly. Lighting up either right after the reset or sometimes not lighting up at all without resets.

Someone on here got ahold of Ford Engineering years ago and they acknowledged it was an issue but weren’t going to devote resources to it. Understandable.

Yes, just like the totally useless TPMS system on these cars (NO actual individual pressures given {like the GM system does}, will not tell you WHICH tire is low), it is also useless as far as I am concerned.

I wish they would have forgone BOTH 'systems' and instead given us a real, accurate, engine oil pressure and temp, and coolant temp, gauges.

 

[the duke]

Yes, just like the totally useless TPMS system on these cars (NO actual individual pressures given {like the GM system does}, will not tell you WHICH tire is low), it is also useless as far as I am concerned.

I wish they would have forgone BOTH 'systems' and instead given us a real, accurate, engine oil pressure and temp, and coolant temp, gauges.

$$$

 

[Stkid93]

Thanks everyone for chiming in and helping to create a useful thread

I feel we gained some valuable information and maybe this thread can help more people in the future which is what this is all about.

I think we touched on everything but if anyone has more to contribute feel free to keep it going.