New cars: Oil viscosity detection?

[Raven]

Hi guys,

I heard some rumors at work that some vehicles can tell if the wrong oil is added after an oil change...

And then they shut down the engine or something to that matter, popping up some message to that matter...

Anybody know anything about this?

 

[gathermewool]

Yea, right

 

[Leo99]

Instead of a viscosity sensor, why not a level sensor that actuates a valve to add more oil? You fill up a reservoir with 2-5 quarts of oil and when the sensor detects a few ounces low in the sump, it opens a valve and lets in a few ounces to top things off. With the new 25k mile oils, you'll want a way to keep the level topped off and make it as maintenance free as possible.

 

[merconvvv]

Leo99 thats one good idea.

 

[aquariuscsm]

Originally Posted By: Leo99
Instead of a viscosity sensor, why not a level sensor that actuates a valve to add more oil? You fill up a reservoir with 2-5 quarts of oil and when the sensor detects a few ounces low in the sump, it opens a valve and lets in a few ounces to top things off. With the new 25k mile oils, you'll want a way to keep the level topped off and make it as maintenance free as possible.


Kind've like those old school oil injection 2 stroke bikes. You'd fill up the oil reservoir with two stroke oil and it would inject it rather than mixing it up in the gas tank.

 

[SpecM]

Yes! Dodge/Chrysler Hemis with MDS can set a DTC if 20wt oil is not used. Apparently it skews the MDS

multi displacement system

 

[oldhp]

Well I guess my 2012 RAM Hemi was stupid because I ran 5W30 in it all the time with no CEL's or MDS shutoff. When under 32° it always went into MDS when dead cold start up. Now maybe 20W50 would be a problem.....

 

[rubberchicken]

Originally Posted By: aquariuscsm
Originally Posted By: Leo99
Instead of a viscosity sensor, why not a level sensor that actuates a valve to add more oil? You fill up a reservoir with 2-5 quarts of oil and when the sensor detects a few ounces low in the sump, it opens a valve and lets in a few ounces to top things off. With the new 25k mile oils, you'll want a way to keep the level topped off and make it as maintenance free as possible.


Kind've like those old school oil injection 2 stroke bikes. You'd fill up the oil reservoir with two stroke oil and it would inject it rather than mixing it up in the gas tank.


Or 2 stroke outboard engines over the last 30 years. Or 2 stroke PWCs.

 

[rubberchicken]

Originally Posted By: Raven
Hi guys,

I heard some rumors at work that some vehicles can tell if the wrong oil is added after an oil change...

And then they shut down the engine or something to that matter, popping up some message to that matter...

Anybody know anything about this?


My personal opinion is that this is really unlikely.

 

[Raven]

If I think about it, it's actually not to hard to figure out the oil weight is not correct.

Let's say 0W oil at 20 deg C has a viscosity of 40 cSt, and maintains an idle oil pressure of 2.8 bar. (Making up numbers here. Conversational purposes only.) When you pump that through the engine, and if you have an oil pressure sensor sensitive enough, you can tell based on the pressure at that oil temperature if it's lower or higher than a certain range. Whereas if someone stuck 10W oil in it, and at that same temperature, it might have a viscosity of 90, and thus an idle oil pressure of 4.8 bar, you'd know something is amiss.

Still curious about the matter: I'll have to poke around to see what this rumor comes from.

 

[Ducked]

Originally Posted By: Leo99
Instead of a viscosity sensor, why not a level sensor that actuates a valve to add more oil? You fill up a reservoir with 2-5 quarts of oil and when the sensor detects a few ounces low in the sump, it opens a valve and lets in a few ounces to top things off. With the new 25k mile oils, you'll want a way to keep the level topped off and make it as maintenance free as possible.


Just to extend that idea a bit further, in your..lets call it.."top off tank" you could have some simple device....lets call it a "dip stick" which would allow you to...lets call it "check the oil"..................

Sorry, stupid idea, obviously. Would never ever work. Don't know WHAT I was thinking of.

 

[Ducked]

Instead why not a level sensor in your..lets call it.."top off tank" that actuates a valve to add more oil? You fill up another reservoir with 2-5 litres of oil and when the sensor detects a few cc's low in the "top off tank", it opens a valve and lets in a few cc's to top things off. With the new 25k mile oils, you'll want a way to keep the "top off tank" topped off and make it as maintenance free as possible.

 

[Garak]

Originally Posted By: SpecM
Yes! Dodge/Chrysler Hemis with MDS can set a DTC if 20wt oil is not used. Apparently it skews the MDS

multi displacement system

What happens with people that use such an engine in our winters and never take long trips to get the oil up to operating temperatures?

Raven: Of course, it's possible, but think of what you have to really accomplish here. An ILSAC 30 and a 5w-20 are pretty much two sides of one line. Trying to measure oil pressure and temperature accurately enough on the fly to determine if someone is using an ILSAC 5w-30 versus a 5w-20 seems to be a bit of a nightmare.

 

[Quattro Pete]

Originally Posted By: SpecM
Yes! Dodge/Chrysler Hemis with MDS can set a DTC if 20wt oil is not used. Apparently it skews the MDS

multi displacement system

Yet the SRT version calls for 0w-40 oil and it works with MDS just fine there?

 

[Quattro Pete]

Originally Posted By: Raven
Hi guys,

I heard some rumors at work that some vehicles can tell if the wrong oil is added after an oil change...

And then they shut down the engine or something to that matter, popping up some message to that matter...

Anybody know anything about this?

that would be a solution to a problem that does not exist, IMO.

Most if not all engines can run on a variety of oil grades. Not that long ago, vehicle owner manuals would actually list all the different grades. Running 5w30 instead of 5w20 is not going to cause any harm, so having a computer shut down the engine because of it sounds like major overreaction.

Proper oil level is way more important than grade, IMO. Yet, many engines still dont have oil level sensors that would alert the driver that they should top off if they forget to check the dipstick.

 

[gfh77665]

So what would this alleged system do if & when the vehicle is occasionally driven in the bitter cold, and even a thin oil thickens up? What then?

 

[eljefino]

I've seen cars throw a code for never reaching operating temperature, because the water thermostat is faulty.

It would be easy to run the MDS diagnostic after 5 minutes of stable 180+ water temp. It could take a week but would run eventually.

My beater camry threw a soft code (no CEL) for the VVti being gummed up... I changed the oil and it was happy.

 

[OVERKILL]

Originally Posted By: Quattro Pete
Originally Posted By: SpecM
Yes! Dodge/Chrysler Hemis with MDS can set a DTC if 20wt oil is not used. Apparently it skews the MDS

multi displacement system

Yet the SRT version calls for 0w-40 oil and it works with MDS just fine there?


I remember Clevy was able to get his Charger to throw the code with 0w-40 in his '06 that spec'd 5w-20, but it was like -35C in Edmonton and it only ever happened the once IIRC.

 

[HerrStig]

I'm sure the technogeeks could design one, and the cost to repair it when it breaks would be very reasonable .

 

[rubberchicken]

Originally Posted By: Raven
If I think about it, it's actually not to hard to figure out the oil weight is not correct.

Let's say 0W oil at 20 deg C has a viscosity of 40 cSt, and maintains an idle oil pressure of 2.8 bar. (Making up numbers here. Conversational purposes only.) When you pump that through the engine, and if you have an oil pressure sensor sensitive enough, you can tell based on the pressure at that oil temperature if it's lower or higher than a certain range. Whereas if someone stuck 10W oil in it, and at that same temperature, it might have a viscosity of 90, and thus an idle oil pressure of 4.8 bar, you'd know something is amiss.

Still curious about the matter: I'll have to poke around to see what this rumor comes from.


My opinion is that the value of that information, compared to the cost of determining that information, is minimal to non-existent. Lots of cars and trucks are sold in the North such as Canada and Alaska, and also in the South such as Mexico or even Saudi Arabia. I do not know this as a fact, but it would not surprise me that a Chevy Suburban sold in Saudi Arabia has a different oil spec than the same truck destined for Canada.