2.7 crd overheating on inclines

[Seriusrod]

Originally Posted by JeanLuke

How did this end?

It was the radiator that was clogged.
As soon as i had the car, i did a testing travel on that highway it heated before and this time all went good.
Also at operating temp the gauge was at around 85 degrees, while before was always at 100.
It only raised to 100 on a very steep incline, that tells me that perhaps there's something more behind, but never passed from there.

[OffroadSpike]

Do you know the part number for the 2.7 radiator?

I'm having similar problems, car gets to just under 100ºC going on short uphills but cools down again on flat to around 90ºC. This is only happening in summer. I'm worried because I'm having a trip in September on the mountains which will have a lot of uphills at low speeds and I don't know if temperature is going to go past 100ºC

I changed the thermostat about 6 months ago because it was stuck open and the working temperatures were 60ºC instead of 87ºC. It works fine after that.

Another possibility is the water pump which is doing a weird noise, doesn't sound like a grinding bearing but definately sounds weird. The sound can only be heard with the engine and belt off, with the engine on it sounds completely fine.

https://www.youtube.com/shorts/SONMM14mKbw

How can I check the pump is working without taking it out? To take out the water pump you need to remove the radiator, fan, and a lot of stuff that I'm not willing to remove right now.

[JeanLuke]

Originally Posted by OffroadSpike

To take out the water pump you need to remove the radiator, fan, and a lot of stuff that I'm not willing to remove right now.

I've changed my water pump (it was leaking) without removing all that stuff. It is very tight, but it can be done. Yes, I did shred my knuckles. I saw that as a small price compared to dismantling the front of the car.

Sounds like you need to change yours if it is grinding.

For the radiator, I have read good reports about the Nulon Extreme flush. I have not used it myself but plan to give it a go soon. https://www.nulon.com.au/products/co...lush-degreaser

I am also looking at buying a proper flush gun: https://www.supercheapauto.com.au/p/...un/656321.html

[JeanLuke]

I also should have added that the hydraulic fan does not ramp up to full speed until the coolant is at 106 degrees. It starts the ramp-up in the mid-to-high nineties (cannot recall the exact number). I have tweaked mine to be full speed at 103 degrees.

My point is that 100 degrees isn't necessarily a problem. I have learned not to get concerned until I see ~105 degrees.

Radiator part number is 52079971AB.

[OffroadSpike]

Originally Posted by JeanLuke

I also should have added that the hydraulic fan does not ramp up to full speed until the coolant is at 106 degrees. It starts the ramp-up in the mid-to-high nineties (cannot recall the exact number). I have tweaked mine to be full speed at 103 degrees.

My point is that 100 degrees isn't necessarily a problem. I have learned not to get concerned until I see ~105 degrees.

Radiator part number is 52079971AB.

Is the engine heating up to 100ºC normal in this car? I was expecting the gauge to be at 87ºC in any circumstance. I find it a bit preocupying for the temperature to raise that fast on some mild uphills, specially when I'm not towing anything. I guess I'll wait till past summer to remove radiator and water pump to inspect what's happening with those.

[OffroadSpike]

Hey guys, never got an answer. Is 100ºC common to see at highway speeds in this car? My mom has a the Mercedes C220 with the OM646 which is basically the same as the 2.7 CRD but with 4 cylinders instead of 5. Her car always runs at 87ºC no matter how hot or fast I'm going.

[RTB]

Originally Posted by OffroadSpike

Hey guys, never got an answer. Is 100ºC common to see at highway speeds in this car? My mom has a the Mercedes C220 with the OM646 which is basically the same as the 2.7 CRD but with 4 cylinders instead of 5. His car always runs at 87ºC no matter how hot or fast I'm going.

Hi OffroadSpike, Just to save myself retyping, I have copied some comments below I made in a post on Facebook.

Correct system operation is. Thermostat starts to open at 89 and is full open by 96. Fan is off when cold, but ramps to a minimum speed at water temp 95. then does not change speed until water temp hits 100. Then ramps to full speed by 106.

Engine temp will fluctuate between 95 and 100 as load changes due to the cooling fan being constant speed in this range. By these temps, your thermostat is full open and just relying on the change it fan speed to control the engine temp. The fan doesn't change speed at these temps, so engine temp will rise. If it was warm outside, then your description is normal.

I used to worry a lot about my engine temp. After much reassurance from the guru's on the forum, I became more happy with it. By the way the ECU is tuned, it seems Jeep are happy for the engine temp to run anywhere from 95 to 100, but not more than 106. That said, my oil pressure used to play up when the engine got over 100. It is for that reason that I lowered my maps to ramp the fan up from 95, not wait. If everything else is working ok, I'd say yours is fine