Oil too hot, heater too cold

[jeffhoward001]

Hi All -

 

I'm hoping to get some guidance on how to proceed with the dealership.  Sorry for the long back-story, but understanding the scenario is helpful.

 

Here's the quick background on the issue:

 

• 2012 Journey V6, runs fine with normal city/highway driving.  Only chronic issue was that the heater doesn't get very hot.  If it close to freezing, could take close to an hour
• Here's the issue: When ambient air temp is hot (+90's) and the Journey's under heavy load (lots of cargo, big hills) the oil gets way too hot
• In going up a big mountain pass in Arizona when it was 102 ambient air temp, Journey threw a CEL
• Drove straight to AutoZone and pulled the codes: P0394: Camshaft Position Sensor B Circuit Intermittent (Bank 2)
• Coolant temp was higher than normal (understandable given the circumstances) so we let the car cool down.  After cooling down everything seemed fine
• Given the CEL scare, I started watching the coolant, oil, and trans temps more closely
• Coolant and trans would heat-up/cool-down as expected, but the oil would get as hot as 270 degrees on hills, and take forever to cool down.  When it got above 260 degrees, I would pull over and let it cool down.
• Drive another 500 miles with no issues, then ambient temp got into the high 90's again and I didn't noticed that the oil was 275 degrees.  As soon as it created 275, another CEL
• At this point is was pretty clear that the oil was getting too hot and clearly causing the P0394

 

So best I can estimate, the issue is that oil cooler isn't working properly.  I found some posts that suggesting that the heater core is fed off output from the oil cooler.  That's when I had the "ah-ha" moment.  If the heater isn't working well, and the oil-cooler isn't able to keep the oil temps down, then it would seem that coolant isn't passing through to cool the oil, and very little coolant is making it the heater core.

 

This all makes sense to me, but the dealer is having a tough time reproducing the issues because A) it's summer now so the heater test is near impossible, and B) it's pretty tough for the tech to do a legit load-test for the oil heat issue without driving the car for an hour into the mountains.

 

Any suggestions on how to proceed with the dealer?  Replacing the oil cooler is a pretty labor-intensive task, but that seems like the most logical bet.  Is it reasonable to ask for the oil cooler to be replaced under warranty if I drive the car up in the mountains take a picture with my phone to prove that it's cresting 260 degree which the coolant stays below 220?  A 40-degree delta make it seem pretty clear that the oil is bypassing the cooler.

 

I'm not over-reacting, right?  The only should crest 270 degree even under load?

[2late4u]

have you replaced your thermostat,or is it the OEM, you might want to do that and a coolant change just to rule that out,also is the electric fan kicking on and off like it should, check the connector to the fan as well to make sure it connected and tight and look for any deformations to the connector as well,  as far as the oil cooler is concerned most complaints on it is that they crack or leak cant remember anyone complaining about one going bad by restricting coolant problems...good luck

[Borjawil]

Could also be a clogged/resteicted heater core, or passage in cooling system. Coolant flows through heater core and blower fan blows air across it to produce the vent heat. Have you put any additives in the coolant? Coolant color look ok? 

 

You can back flush the heater core to remove any debris or clogs. While you can flush the entire coolant system (I'd do it first just to be sure) doing the heater core along will allow for better diag and more pressure through it. Be aware though heater cores don't take a lot of pressure. A flush kit at a parts store will allow for easy adaptation of garden hose to coolant system. But see above about the thermostat. If it's sticking or faulty it may not be opening correctly once the car is heated up. Make sure you have proper oil and coolant levels as well.