Oil Expansion

[greg_J35]

The Nissan came with two “free” oil changes from the dealership. My wife took it in for another issue and had them perform an oil change. The next morning I checked the oil level and it was at more than a half quart low. The service representative was contacted and said the following, “we never fill to capacity because the oil expands when heated”.
I call bovine excrement on the representative’s reply. What say you? Thanks

 

[MolaKule]

@greg_J35 The rep is right:

From https://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html:

The change in the units volume when temperature changes can be expressed as

dV = V0 β (t1 - t0) (2)
where
dV = V1 - V0 = change in volume (m3, ft3)
β = volumetric temperature expansion coefficient (m3/m3 oC, ft3/ft3 oF)
t1 = final temperature (oC, oF)
t0 = initial temperature (oC, oF)

The density of a fluid when temperature changes can be expressed as

ρ1 = m / V0 (1 + β (t1 - t0))
= ρ0 / (1 + β (t1 - t0)) (3)
where
ρ1 = final density (kg/m3, lb/ft3)
ρ0 = initial density (kg/m3, lb/ft3)

 

[oldcodger]

I agree dealer BS.
I have never noticed a significant change in dipstick reading when checked cold or hot. By hot I mean checking 15 minutes after a hot shut down.

 

[redbone3]

The Nissan came with two “free” oil changes from the dealership. My wife took it in for another issue and had them perform an oil change. The next morning I checked the oil level and it was at more than a half quart low. The service representative was contacted and said the following, “we never fill to capacity because the oil expands when heated”.
I call bovine excrement on the representative’s reply. What say you? Thanks

In every pile of BS there is a small truth. Oil expands with heat ,but not that much.

 

[JTK]

It was a half quart below the minimum level indication on the dipstick?

Sad, but sounds like a free dealer oil change.

 

[greg_J35]

It was a half quart below the minimum level indication on the dipstick?

Sad, but sounds like a free dealer oil change.

It was more than a half quart below the full mark. I am one who has and will continue to maintain at the full mark. I’m reminded of an exchange at a Ford dealer service representative and a customer over this same issue. The customer checked the oil level after the oil change and it was low. The customer went on to firmly state, “the oil level was full when I arrived and I won’t leave until it’s full again.” The fast scramble was on to get the oil level to the full mark. You would just had to have been there. Lol.

 

[Titan]

...and that's one reason I don't always use the "free oil change". Two more: they over-tighten both the drain plug and the filter. And, they don't clean any drips that might have occurred. If they'd use someone other than the newest person to do this relatively simple job, perhaps they would do better, but, that's not the best use of an experienced Master Mechanic (if there is still such an animal).

 

[greg_J35]

@greg_J35 The rep is right:

From https://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html:

The change in the units volume when temperature changes can be expressed as


The density of a fluid when temperature changes can be expressed as

I appreciate your knowledge and response.

 

[greg_J35]

...and that's one reason I don't always use the "free oil change". Two more: they over-tighten both the drain plug and the filter. And, they don't clean any drips that might have occurred. If they'd use someone other than the newest person to do this relatively simple job, perhaps they would do better, but, that's not the best use of an experienced Master Mechanic (if there is still such an animal).

It definitely doesn’t build my confidence with the dealership.

 

[ZeeOSix]

The Nissan came with two “free” oil changes from the dealership. My wife took it in for another issue and had them perform an oil change. The next morning I checked the oil level and it was at more than a half quart low. The service representative was contacted and said the following, “we never fill to capacity because the oil expands when heated”.
I call bovine excrement on the representative’s reply. What say you? Thanks

I'm assuming you checked it cold in the morning? What's the level when the oil is fully hot ... checked 15-20 minutes after engine shut-off.

 

[Chris142]

The 10 qts in my diesel pick-up will expand about a qt between cold and running temps. Same with atf as those are also checked at operating temp

 

[Greasymechtech]

Too many id1ots out there at dealerships, and sad when people believe them as knowledgable

There is drain down, and temp expansion/contraction oil. My cold level is 1/4" higher from drain down when compared to the expanded hot level 5-minutes after shut down.

A Nissan 2.5, with its 'massive' oil sump, isn't going to vary too much concerning temp. A quart? We call that hack dealer tech incompetence. 1/4" either way... close enough.

One automaker understands optimum oil level. Your owners manual covers the oil level check procedure.

 

[OilUzer]

If you take the car for warranty work and oil is half way between F and L, they may lecture you to keep it full.

Toyota dealership did that to my Tacoma (oil was half way between L & F) and I went back and they added more oil. They guy said sorry.

Oil expands and I'm sure manufacturers are aware of that but all my owner's manual say check oil level when cold. iirc, some of them recommend checking it again the morning after or after several hours. Also when I change oil and add x quarts (per OM spec) of COLD oil, it comes right near the F mark +/- a little.

The most meaningful expansion is in dealer's wallet.
Multiply half a quart by number of customers per day, week, month, year ...

 

[Astro14]

If you take the car for warranty work and oil is half way between F and L, they may lecture you to keep it full.

Toyota dealership did that to my Tacoma (oil was half way between L & F) and I went back and they added more oil. They guy said sorry.

Oil expands and I'm sure manufacturers are aware of that but all my owner's manual say check oil level when cold. iirc, some of them recommend checking it again the morning after or after several hours. Also when I change oil and add x quarts (per OM spec) of COLD oil, it comes right near the F mark +/- a little.

The most meaningful expansion is in dealer's wallet.
Multiply half a quart by number of customers per day, week, month, year ...

All of mine say check it hot, five minutes after shutdown, for the most accurate reading.

 

[nicholas]

All of mine say check it hot, five minutes after shutdown, for the most accurate reading.

Me too.
Hot though can take 15mims of highway driving sometimes.
People think when the coolant is at normal, 5mins, then the oil must be as well.

 

[ATex7239]

Oil does expand. That is not wrong. However that should be accounted for in the engine design as it relates to replacing the oil and checking for proper level. Full is full. Assuming you’re following the proper oil change and oil level checking procedures, you don’t have to make a SWAG to adjust for heat expansion.

Now what is BS is they get to charge you for full change but short you some oil. Which sounds like a nice little ancillary financial benefit to some oil bro-science.

 

[barryh]

Of course oil expands when it's hot but in a sump it makes little difference to the level so the dealer is for the most part talking nonsense.

Where temperature does make a big difference to the dipstick reading is in auto transmissions, not because ATF expands any more than engine oil, it's because the gearbox mechanism is submerged in oil.

 

[DGXR]

It was more than a half quart below the full mark. I am one who has and will continue to maintain at the full mark. I’m reminded of an exchange at a Ford dealer service representative and a customer over this same issue. The customer checked the oil level after the oil change and it was low. The customer went on to firmly state, “the oil level was full when I arrived and I won’t leave until it’s full again.” The fast scramble was on to get the oil level to the full mark. You would just had to have been there. Lol.

1/2 quart low means significantly below the add mark. Too many people saying the oil level is low when it's not 100% perfectly full.
If it's between add and full marks as you described, the level is not low -- they changed the oil and the level is OK. Reference most owner's manuals, which say between the marks is OK (again, not low). If you insist the oil level is always full because the engine burns or leaks oil, that is your problem, not the dealer's. If you insist that the oil level is always full because of hard usage (racing, towing/hauling, etc.) again that is your problem and not the dealer's. Sure it would be better if the oil service came with a full sump, but according to most manuals it's not necessary.
Many dealers and quick lubes specify the quantity of oil included in their oil change service (e.g. up to 5 quarts). If that quantity puts the oil level between the marks, I would expect them to call it good. Their only option is to add more oil and charge the customer more than the advertised price, which is likely to play out worse than just leaving it alone.

 

[DavidJones]

My question would be...if Nissan called for "X" quarts, did the dealership put "X" quarts back in it? Nissan had an amount in mind and that's what should go back in it. My F150 calls for 6 quarts. I let it drain and then put 6 quarts in it and wherever that lands on the dipstick is full.

 

[ZeeOSix]

Some engines have a 'full cold" and also "full hot" marks on the dipstick. Ford Coyote is an example.