Terrible MPG
 

Hey All,
I have a 2008 T&C 3.8 Touring and I am getting TERRIBLE gas mileage.
Just took her on a all highway trip and (using the old school way of finding out MPG) got 15mpg.

She has new spark plugs, wires, MAF sensor. I've tried additives (sea foam, lucas, techron). She has decent tread on tires.

What else can I do? No check engine light either.

Welcome to the forum!

Plenty folk on here will chip in, but this topic has been discussed so many times on here you need to search first and see what you can find.
(A lot of the answers are on CRD or other versions, but the same principles can apply to all the models one way or another)

https://www.chryslerforum.com/forum/...highlight=poor

https://www.chryslerforum.com/forum/...highlight=poor

For a start!

Poor MPG can be anything on these things, and you've got a pretty big engine there so I wouldn't go expecting any miracles on the MPG, I can only base this on mine (2.8 Diesel 2005) and I get 29.9MPG pretty constant, that's combination of longer and shorter journeys and I count myself pretty happy with that figure.

Petrol.

Can you tell us if you are experiencing any thing like loss in power when booting it..This must be an Air/Fuel issue. Think some may get my drift here.

Coolant Sensor ?

I am having the same problems here, did you find the answer to your problem? Chrysler Voyager 2004 ( same as Chrysler Town and Country) Petrol 3.3l in Australia.

I have checked for binding brakes with brake expert - no problems. The engine achieves normal temperature, is not running cool. I have checked wheel alignment at suspension experts even purchasing and fitting a camber adjustment kit and had it installed. I have checked exhaust/muffler at exhaust experts, repaired and now all good. Both upstream and downstream O2 sensors have been replaced. Air intake temp. sensor was faulty and replaced. Engine coolant sensor was replaced. None of these replacements/repairs has made any difference to the fuel consumption. Fuel consumption is calculated at the pump. Kilometres divided by litres. converting to 20 litres per hundred or in US galons: 12 MPG around town. 21 MPG on a highway run.

I recently ran across similar mpg drop with my 04 T&C(3.8) with SAME engine management system. It also started showing odd shifting at cruising speeds. I live out in the country(rural), so almost nil stop and go driving. Motor ran fine and NO codes. What I finally decided to do was to swap the TPS on the throttle body and the MAP sensor (mounted on the intake manifold) from my parts donor 04 3.8. My mileage came up from 16.5 to an average of 21 mpg for the last 3 tanks run. No more trans. shifting concerns either and running like a champ at 185,000 miles.
Both parts are easy to replace and I've found the TPS is best replaced by unbolting the throttle body(EASY to do) for ease of removing the 2 torx head screws that the TPS has for mounting, as it sits on the firewall side of the throttle body. The map has a 10mm head bolt that that secures it to the intake manifold, and just pulls out..EASY JOB!
Hope this helps you some!

Thank's for the reply. I forgot to mention I had changed the MAP recently but the TPS might be something I can do. Except I don't know what TPS stands for?

Cheers.

Oh. got it now by Dr. Google. Throttle body sensor.

:)

Sorry for the late reply, The proper name is Throttle Position Sensor, Hence the abbreviation...TPS There are 3 bolts that fasten the throttle body to the manifold, and the throttle cables that slip off, and Pretty sure just 1 small vacuum hose to slip off, and 2 wire connectors for TPS and Idle control solenoid. It is a lot easier to change the TPS that way than doing it with the throttle body mounted.Just watch as you remove the TPS for proper twist of sensor to the shaft it slips over. Good Luck!