Is overheating an issue?

nU7OuxIx

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We're planning on buying a JLU with a Diesel in the upcoming months. We plan on taking a lot of road trips with it and towing about a 2500lb a-frame camper in the future. In doing my usual research, I've come across a number of threads talking about overheating. I have a feeling that people are gathering the information from the off-road pages and the vehicle isn't overheating, it's just really hot and makes the driver uncomfortable.

Do the Diesels overheat where this is something I should be concerned with? I've also read that the regens can get the exhaust pretty hot. Is it hot enough to start dead leaves on fire if idling in the forest?

Thanks!





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rickinAZ

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We're planning on buying a JLU with a Diesel in the upcoming months. We plan on taking a lot of road trips with it and towing about a 2500lb a-frame camper in the future. In doing my usual research, I've come across a number of threads talking about overheating. I have a feeling that people are gathering the information from the off-road pages and the vehicle isn't overheating, it's just really hot and makes the driver uncomfortable.

Do the Diesels overheat where this is something I should be concerned with? I've also read that the regens can get the exhaust pretty hot. Is it hot enough to start dead leaves on fire if idling in the forest?

Thanks!
I've heard (but not experienced) this as well. I've had mine out in 100+ weather with no problem. I've always thought that winches, bull bars, and auxiliary lights block airflow and the over-heaters are potentially running those obstructions. I read that cooling was an engineering challenge in developing the EcoDiesel, so clear access to the radiator is especially important.
 

Capricorn

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I drove in 115-120℉ in Vegas summer on hilly freeway, and never experienced overheating. I didn't do any towing though.
Even climbing a hill at 65-70 mph, the max oil temp I notice was 235℉, and about 220℉ coolant temp even in the hottest summer days. In winters of Vegas (45-50℉), on the same route, I see about 222℉ oil and 210℉ coolant temps.
 

JLURD

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I’ve yet to come across any patterned suggestion of inadequate cooling with the 3.0. Underheating on the other hand, I’ve got plenty of experience with that issue.
 

Ruby Clatterbox

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7k miles now. Driven in 100 deg + out west and of course Florida heat back home. No issues.
 

dchemphill1

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Diesel engines run cooler than gas engines. My Kubota tractor has a hard time getting warm in the winter. Transmission heat may be another thing when towing and traveling hills etc... I will admit I don't know much about the eco diesel.
 

DaltonGang

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Diesel engines run cooler than gas engines. My Kubota tractor has a hard time getting warm in the winter. Transmission heat may be another thing when towing and traveling hills etc... I will admit I don't know much about the eco diesel.
Yes, traditionally made Diesels take a long while to warm up, and rarely overheat. I'm not so sure with the modern made diesels, with the EGR systems pumping exhaust back into the engine.

..
 
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nU7OuxIx

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I’ve yet to come across any patterned suggestion of inadequate cooling with the 3.0. Underheating on the other hand, I’ve got plenty of experience with that issue.
Can you expand? I live near Chicago and it does get pretty chilly in the winter. Having a heated cabin is a big deal and having it heat fast. When you talk about underheating, I'm thinking that it takes a long time for the cabin to heat.

Is there a noticeable difference with having the cabin heat up due to a diesel vs gas?
 

Capricorn

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Compared to the gas engine, both the coolant and oil temp warm up much sooner in the 3.0L.
The cabin gets heated very fast.

For Chicago winters, you should however get a block heater, unless you are parking it outside on the street.
 

rickinAZ

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Can you expand? I live near Chicago and it does get pretty chilly in the winter. Having a heated cabin is a big deal and having it heat fast. When you talk about underheating, I'm thinking that it takes a long time for the cabin to heat.

Is there a noticeable difference with having the cabin heat up due to a diesel vs gas?
Now granted it isn't as cold here as Alaska, but this is the quickest warming vehicle I've ever owned. I start it, wait a second or two, and by the time I'm 100 yards away from my garage there are the beginnings of warm air coming through the HVAC.
 
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nU7OuxIx

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Thank you all for the responses and information. I keep going back and forth with the 3.6L gas and the diesel. I've never owned a diesel before so I have a lot of questions. Thanks for taking the time to respond!
 

JLURD

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Can you expand? I live near Chicago and it does get pretty chilly in the winter. Having a heated cabin is a big deal and having it heat fast. When you talk about underheating, I'm thinking that it takes a long time for the cabin to heat.

Is there a noticeable difference with having the cabin heat up due to a diesel vs gas?
You’ll get cabin heat just fine but once you cold start from +10F or lower, it will take over 15 minutes of driving to reach normal operating oil and coolant temps without a winter grille cover. Below zero it likely won’t reach normal temps at all unless your operating load is quite high. I’ve started mine from a 55-degree heated garage and never reached normal oil or coolant temps below zero outside before I had the grille cover. FWIW, that’s not far off what I’ve seen my block heater keep the oil at when parked outside around zero degrees.
 

Dieselfumes57

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Once a delete comes out and for those who are willing to go that route will see the egr is the biggest heat producer for this engine.
 

JLURD

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Once a delete comes out and for those who are willing to go that route will see the egr is the biggest heat producer for this engine.
Yea this is one of the reasons a lot of VW TDI owners ran dynamic EGR tunes...get the engine to temp quicker and then shut it off. Little did they know, the factory tune was doing much the same lol. That said, VW wasn’t using post-DPF exhaust gases and as far as I can tell, the blended 3.0 exhaust gases are significantly cooler than many older EGR systems used so the effect regarding engine warming is likely less.
 

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