# 2009 Routan 4.0 L Poor Fuel Economy



## ORRoutan (Mar 12, 2015)

Our 2009 Routan has terrible gas mileage in town, probably around 14-15 MPG (on long road trips we can get about 22). I can sit in my driveway, reset the MPG gauge on the dash and within seconds watch it drop from 14 to 13.9 to to 13.8 to 13.7...
Was wondering if its the EGR? Anybody else have an MPG in this range? 
Some things I've noticed:
- No Check Engine Light 
- When I change the oil the MPG improves but only slightly. After a while it will drop again.
- The idle is ever so slightly rough, or maybe I should say it is not completely smooth as it is in my 2004 Jeep.
- When maintaining speed (say 40 MPH) on an incline you can feel a bit of hesitation in the acceleration. Only I notice this, not my wife....


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## Zambee500 (Jun 23, 2011)

Could be any number of things, so not sure I'd just go throwing ~$100 in parts at it to see if it's the EGR. Rough idle, hesitation, and drop-off on fuel efficiency are consistent with bad EGR valve though. Did you ever have the coolant leak from the bad Y-diverter tube?

Honestly, 14-15 MPGs doesn't seem so far off for city driving, although perhaps a tad bit low. The 4.0L is a gas hog, especially with any 'city' traffic driving. Too many variables though to jump to bad EGR diagnosis. 

We historically have gotten 15-17 MPGs in city (some mixed) driving. When it started dropping in the 12-14 range last fall I became more concerned. When it started stalling after cold starts around Thanksgiving, I finally had the EGR valve replaced and it was HUGE improvement on MPGs. But it only went back to the 15-17 range in all-city driving, and 22-25 on the hwy. I saw biggest improvement on the hwy driving though. But I wouldn't have necessarily looked at the EGR valve if it hadn't started stalling when cold w/o throwing CEL code - a more obvious symptom for bad EGR. We also had the Y-diverter tube coolant leak quite awhile back, which also causes the EGR valve to go bad.

But could be other things. Does yours warm up fairly quickly and hold 195* once warmed up? A stuck-open t-stat or bad temp sensor will negatively affect MPGs when the motor has problems warming up and holding operating temp. Rough idle could be bad engine/trans mounts too.


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