I have an 06 Liberty CRD, when I first got it at 80,000 the fuel millage was around 28 mpg most the time, dep on weather. It is now around 23 and less dep on weather. I have changed the fuel filter and air filter. My questions are; #1,, do the valves need to be adjusted or do they have hydrollic lifters, and don't need adjustment,, as a gas rig, if the valves need to be adjusted,, how often, #2 at 107,000 miles do the injectors need to be replaced, cleaned or flow tested?? What other things to do am I looking at as I am concidering selling it if I can't get the fuel millage back up.
I want to PRE thank any good info.

Denny

First off, at 107,000 miles, your injectors should still be working great but you probably should look at replacing your fuel filter. Especially if its never been replaced.

Most IMPORTANT, at that mileage the timing belt definitely needs to be replaced VERY SOON.
If it breaks, you will no longer be worried about poor fuel mileage.

The valves dont need to be be adjusted. The rocker arms have hydraulic lash adjusters.
HOWEVER, it is not uncommon for the rockers to wear out prematurely due to poor lubrication and excess soot buildup in the oil.

Do you notice any smoke coming out of the exhaust?
Excess black smoke is an indication that the engine is not getting enough air, which could indicate a problem with the turbo or the EGR valve. Both of which could hurt your MPG.
Its also very common for the MAP sensor to get covered in black gunk, which will effect the operation of the turbo.

Poor fuel mileage can be caused by lots of things.
Its very common for the engine thermostat to fail in the open position, causing the engine to run at a cooler and less efficient temperature.
You choice of tires could also effect MPG.
In my case, I switched to a more aggressive off-road tire and my MPG went from 26-27 to 22-23.

Lastly, check out the CRD Love that Torque section of the forum, lots of good info there.
And read Noob Guide at the top of the page.

_________________
U.S. Army Retired

Thanks for the reply Flash. I forgot to mention that I changed the fule filter regularly. Now my KJ has some new issues. The turbo underboost, 299 has been on there since I bought it, (old issue) now it has a 128 code and the viscus pump never comes on and the thermostat is not working and I have just put a new stat in and it, and still doesn't work.



I live in WA state. In my younger days,, it would be a chalnge to me to work on this KJ,, but after working on rigs since I was 15. At 62 I just am not excited about relearning these new rigs. I can fix this stuff it is just the trouble shooting that I dont know how to do. Any help would be great. Thanks Dennis

First, dont worry about the viscous heater. Just unplug it or pull its relay and forget about it forever.

P0299 = underboost
The most likely causes are: leaks from the intercooler hoses, dirty or bad MAP sensor, bad turbo control vacuum solenoid(s), stuck open EGR valve, or a bad turbo.

P0128 = coolant temp too low
This is a very rare code for a CRD. Even for ones with a bad thermostat.
What did you replace your thermostat with? Crown or Mopar? Crown = crap!
A CRD with a bad thermostat will still warm up even in freezing weather. It will do it slowly but will never get to full operating temperature.
Does the needle on your temp gauge move at all?
A IR temp gun is a alternate way to check your engine temp. Just drive normally and once you get to your destination, pop the hood and point the gun at your thermostat housing.
I suspect you have a bad temperature sensor or bad wiring to the sensor.

_________________
U.S. Army Retired