over heat + milage

dr5chrome · **Posted:** Tue Jun 16, 2015 1:39 pm

Hello all! have not posted for a while - busy relocating.

My Jeep CRD was purchased with all of this relocation in mind.
The 1st leg on this journey started this week with a drive form Colorado to Cali.
I pulled a 10' uhaul trailer. While My CRD had no lack of power, upon heading up hills [i70 & i15], This CRD routinely would heat up very quickly. A few months ago I changed out the thermostat, as the old was stuck open. There was a big difference how this engine heated up. With the old stat, the heat gauge barely got to the 2nd line, no matter how hot the day. The new stat made a huge change to how the engine heated up.

Upon hitting these grades, one time I had to pull over for fear of this engines heat gauge maxing out. I figured out that turning the OD off and slowing to 50-55 mph cooled the engine. Up a grade @ 65 in regular drive would show very hot. on the gauge.

Is this behavior normal for the CRD? ..or is something else wrong??

Everything seems to be operating normally.

As well - I am terribly disappointed in the mileage of this CRD. ALL the maintenance on this jeep has been done. I have ECOtune as well. The best mileage this jeep gets: 13mpg in the city & 23,24 mpg highway... not the mileage I was hoping for.. 30+mpg..

I will be purchasing a small travel trailer 13-16 ft. If this CRD cannot pull this small trailer without overheating, I may need to sell it and purchase aa gas engine..

Any suggestions comments would be helpful.

best regards, Dave W

bugnout · **Posted:** Tue Jun 16, 2015 1:43 pm

Has the fan clutch ever been changed? The OEM clutch didn't last 40k on my CRD. Do you hear the fan's kicking on when it gets hot? The air should be moving like crazy. The electric fan should be running as well, but you should have a hard time talking over the noise from the mechanical fan.

Mountainman · **Posted:** Tue Jun 16, 2015 1:51 pm

I've had two different CRD's overheat on grades with no trailer, and I think it was 2 separate failed heavy duty Hayden fans... I would switch to a flex fan if I was going to run a mechanical. The Hayden only needs to fail once and you can have a toasted engine, and you won't know it has failed until you hit that steep grade!

I switched to electrical, and have had other adventures, but I think the TDF stat will help. I haven't installed one yet.

If you're doing the big grades with a trailer in 90 degree weather with the AC on, I would like to hear from others if the Hayden is able to keep up?

Mountainman · **Posted:** Tue Jun 16, 2015 1:57 pm

oh, and on relatively flat highway with non aggressive tires at 65 mph you should be getting 30+ mpg (if you use cruise or have a very steady foot). Throw a bunch of city, hills, and poor rolling resistance tires into the equation and it's going to be a lot less. The gas pedal on these are really touchy, so cruise control really helps a lot as long as there aren't a bunch of hills.

flash7210 · **Posted:** Tue Jun 16, 2015 2:15 pm

Lots of things can cause any engine to over heat in summer time. Pulling a heavy load up a mountain is one of them.
All the traditional safety measures apply:
Slow down
switch to a lower gear
turn off the A/C
turn the heat on

You should also look into the condition of your engine thermostat and fan clutch.

MPGs are as much about driving habits as they are vehicle condition.

dr5chrome · **Posted:** Wed Jun 17, 2015 2:26 am

thanks.. ill look at the fan clutch. How do I know the fan-clutch is bad? As far as I can see the fan turns. The electric fan does work when the engine is hot.

I have no clue why the mileage is so poor.

best, dw

lacabrera · **Posted:** Wed Jun 17, 2015 9:40 am

Check to see if your brakes are binding. I spent months trying to find the source of poor mpg. Got to the point it must be brake drag, Replaced the rear brake pistons and seals, old ones had expanded and preventing piston from returning but only when hot? That seem to help but also found that the vent on the slave cylinder reservoir was blocked stopping the cylinders from fully returning. I recon that was why the old pistons had expanded from excessive heat build up. Simple problem to solve if you know what to look for.

Mountainman · **Posted:** Wed Jun 17, 2015 12:00 pm

x2 on brakes. There's a write up on how to remove the rubber sleeve and lube the calipers. Makes a big difference

geordi · **Posted:** Fri Jun 19, 2015 12:37 am

As far as the fan clutch - If you haven't changed it, then it is bad. The problem isn't that the fan spins... It is that the fan DOES spin instead of locking to the motor when the heat is too high for the clutch. The factory design is GARBAGE and if you have had it more than 100 miles... It is most likely bad. The replacement is a Hayden Heavy Duty clutch that you can get at your local auto parts store. You will also want a 36mm flat wrench to get the fan nut off the pulley. You do this by jamming a 10mm deep socket into one of the holes below the 5 o-clock position and rotating the pulley counter-clockwise to jam it in place. Then using a mallet and the flat wrench, smack the wrench to rotate that nut lefty-loosey like any other nut and it will spin right off.

The shroud and the fan have to come out together. Cut the shroud on both sides just below the bolt tabs (there is a line in the plastic to indicate a handy place to cut) and throw away the bottom. It doesn't help move the air, and the top now becomes a safety cover. That is why you need to keep the bolt tabs with the top half.

over heat + milage

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