Interesting fluid temp observations on our ‘24 Carnival

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Jan 7, 2009
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Location
Rochester, MI, US, World
Yesterday I got a Bluetooth OBD dongle along with the ‘Car Scanner ELM 327’ app for iOS. Silly name, but GREAT app. I can see oil, coolant, trans temps. Plus a ton of other live info. What really surprised me is just how hot this van runs. Hot=efficient, so I get it.

For coolant, it settles around 210-215f with normal driving. There is a second reading that is always 10f cooler, regardless of what the first temp reads. Not sure which one to trust, but it’s still pretty warm. The reservoir cap is high pressure on this van, like 1.6 bar or something. What I find funny is that the dummy gauge on the dash hits the normal middle position just after 140f.

Trans temp slowly climbs up to about 210, and goes down a bit if coasting downhill. That’s normal from what I’ve seen in other vehicles. I find that this van actually gets the trans up to temp faster than I’ve measured in other vehicles.

The oil was the most surprising. After about 20 mins of driving in 74 degree weather, the oil settled in around 225f. Prolonged coasting or idling brought it down to maybe 219/220. This was with just my son and I in the van and a couple bags. Easy driving with mildly hilly roads. The factory service manual states that an oil pan temp of 226-234f is normal. That’s hot!!! I can see the oil getting hotter with a loaded vehicle, steep hills, AC ON etc.

That 0w20 oil is well into 16 grade territory at those temps. Nonetheless, I’m glad I have this info. I’ll monitor the temps further on some longer drives and road trips just for my curiosity.
 
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Yesterday I got a Bluetooth OBD dongle along with the ‘Car Scanner ELM 327’ app for iOS. Silly name, but GREAT app. I can see oil, coolant, trans temps. Plus a ton of other live info. What really surprised me is just how hot this van runs. Hot=efficient, so I get it.

For coolant, it settles around 210-215f with normal driving. There is a second reading that is always 10f cooler, regardless of what the first temp reads. Not sure which one to trust, but it’s still pretty warm. The reservoir cap is high pressure on this van, like 1.6 bar or something. What I find funny is that the dummy gauge on the dash hits the normal middle position just after 140f.

Trans temp slowly climbs up to about 210, and goes down a bit if coasting downhill. That’s normal from what I’ve seen in other vehicles. I find that this van actually gets the trans up to temp faster than I’ve measured in other vehicles.

The oil was the most surprising. After about 20 mins of driving in 74 degree weather, the oil settled in around 225f. Prolonged coasting or idling brought it down to maybe 219/220. This was with just my son and I in the van and a couple bags. Easy driving with mildly hilly roads. The factory service manual states that an oil pan temp of 226-234f is normal. That’s hot!!! I can see the oil getting hotter with a loaded vehicle, steep hills, AC ON etc.

That 0w20 oil is well into 16 grade territory at those temps. Nonetheless, I’m glad I have this info. I’ll monitor the temps further on some longer drives and road trips just for my curiosity.

does the engine even have an oil temp sensor? Most Kia/hyundai engines don't and they use a calculated oil temp which has no relation with reality. I did a brief search but didn't find an oil temp sensor part number.
 
Yesterday I got a Bluetooth OBD dongle along with the ‘Car Scanner ELM 327’ app for iOS. Silly name, but GREAT app. I can see oil, coolant, trans temps. Plus a ton of other live info. What really surprised me is just how hot this van runs. Hot=efficient, so I get it.

For coolant, it settles around 210-215f with normal driving. There is a second reading that is always 10f cooler, regardless of what the first temp reads. Not sure which one to trust, but it’s still pretty warm. The reservoir cap is high pressure on this van, like 1.6 bar or something. What I find funny is that the dummy gauge on the dash hits the normal middle position just after 140f.

Trans temp slowly climbs up to about 210, and goes down a bit if coasting downhill. That’s normal from what I’ve seen in other vehicles. I find that this van actually gets the trans up to temp faster than I’ve measured in other vehicles.

The oil was the most surprising. After about 20 mins of driving in 74 degree weather, the oil settled in around 225f. Prolonged coasting or idling brought it down to maybe 219/220. This was with just my son and I in the van and a couple bags. Easy driving with mildly hilly roads. The factory service manual states that an oil pan temp of 226-234f is normal. That’s hot!!! I can see the oil getting hotter with a loaded vehicle, steep hills, AC ON etc.

That 0w20 oil is well into 16 grade territory at those temps. Nonetheless, I’m glad I have this info. I’ll monitor the temps further on some longer drives and road trips just for my curiosity.
My 2025 Subaru Forester on the highway is usually around 225F but if there a long hill can easily reach 240F but comes right down after the RPMs drop. Around town it's usually around 200 to 205F.
 
does the engine even have an oil temp sensor? Most Kia/hyundai engines don't and they use a calculated oil temp which has no relation with reality. I did a brief search but didn't find an oil temp sensor part number.
Not sure. But my readings align with the published material in the service manual.
 
Excellent information, as @Jetronic said, I wouldn't be surprised if it was displaying the calculated engine oil temp. I know on my Mazda, which has an actual oil temp sensor and a calculated value, there can be a larger gap than I would anticipate between the calculated oil temp vs actual oil temp.
 
Engine oil temp rises with high RPM so it was interesting to see that confirmed in post #5.
I confirmed this too when I had my 2008 Sedona. Prolonged higher rpm would raise the oil temps pretty quickly. The Carnival makes it hard to rev high since it always tries to upshift as soon as possible. The readings I posted initially were all from 1,500 rpm or lower driving, with the occasional downshift to climb a small hill.
 
Just drove the Carnival on the highway today for the first time in awhile. Ambient temps in the mid 60s. After a short amount of time the oil temp was at 231f, and some of the drive was actually downhill. Going about 73/74 mph. Really thinking a 30 grade is in order here.

I believe this is the sump temp, pre oil cooler. But it’s still hot.
 
Also measured 237f oil temp heading back home, now in the 70s ambient temp. Slightly uphill overall at highway speeds, into the wind.

Most engines will run that high. That is not big deal. Oil is exposed to far higher temperatures around piston rings etc.
if you want to feel better, you can bump grade, but thicker oil means more resistance =more heat.
 
Most engines will run that high. That is not big deal. Oil is exposed to far higher temperatures around piston rings etc.
if you want to feel better, you can bump grade, but thicker oil means more resistance =more heat.
I’ve seen higher for sure, but man, the oil is well into the 16 grade range at those temps.
 
Yesterday I got a Bluetooth OBD dongle along with the ‘Car Scanner ELM 327’ app for iOS. Silly name, but GREAT app. I can see oil, coolant, trans temps. Plus a ton of other live info. What really surprised me is just how hot this van runs. Hot=efficient, so I get it.

For coolant, it settles around 210-215f with normal driving. There is a second reading that is always 10f cooler, regardless of what the first temp reads. Not sure which one to trust, but it’s still pretty warm. The reservoir cap is high pressure on this van, like 1.6 bar or something. What I find funny is that the dummy gauge on the dash hits the normal middle position just after 140f.

Trans temp slowly climbs up to about 210, and goes down a bit if coasting downhill. That’s normal from what I’ve seen in other vehicles. I find that this van actually gets the trans up to temp faster than I’ve measured in other vehicles.

The oil was the most surprising. After about 20 mins of driving in 74 degree weather, the oil settled in around 225f. Prolonged coasting or idling brought it down to maybe 219/220. This was with just my son and I in the van and a couple bags. Easy driving with mildly hilly roads. The factory service manual states that an oil pan temp of 226-234f is normal. That’s hot!!! I can see the oil getting hotter with a loaded vehicle, steep hills, AC ON etc.

That 0w20 oil is well into 16 grade territory at those temps. Nonetheless, I’m glad I have this info. I’ll monitor the temps further on some longer drives and road trips just for my curiosity.
Lubegard Kool•It added to the coolant reservoir brought my temps down. Napa or Rock Auto has it.
 
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