Noob here!

I've searched tirelessly through the threads and can't seem to put together a comprehensive answer for my problems.

2005 Dakota Quad 3.7 V6 SLT 2WD

My pre-purchase research (which unfortunately did not include this forum) said I should be getting about 15 city/20 hwy.

After owning the truck for 7 days, my rough estimate is that I'm getting about 9 mpg. I have a 8 minute commute to work - averaging about 30 mph all the way there. That 16 minute round trip commute knocks off about 20 miles off of the "distance to empty" gauge (which I understand can be very inaccurate), but the gas needle drops about 1/8 inch pretty much everytime I start the truck.

Bottom line: MPG is horrible. I think starting the truck costs me 1/4 gallon!

As for the idle. I've always owned well maintained japanese vehicles. I've experienced rougher idling when the needle drops to about to about 500 rpm...just a low rumble really.

On the Dakota however, if I'm in park, there's a quiet rumble which seems fine, but every so often it "shimmies" almost as though the truck is flexing slightly from side to side. Very bizarre. Not a normal idle for sure, but not quite what I would consider a rough idle either.

Overall, it's a smooth ride. Suspension is a bit bouncy, but I'm not sure if that's normal or not - nothing that alarms me.

Now, I haven't done anything to this truck since I got it. I'm sure it needs an oil change and the alignment is a little off, but other than that, any ideas on my ridiculous mileage and the "shimmy" idle?

I'm looking for affordable fixes since I just dumped alot of cash just to the buy the damned thing! Please tell me there's hope!

Thanks very much for your time guys.

 

Alright, I kinda know what I'm talking about here, hahaha. The pro's on here will be able to help you out a little more with this, but bear with me. There is something on the throttle body that you can take out and clean to improve your idle when you clean it with TB cleaner. I forget exactly what it is, but remember reading about it and seeing pictures. Also, I'd shoot some TB cleaner inside the TB and clean up that butterfly valve. I've heard seafoam works great, but not sure how to go about it using that. Someone will be able to fill in the details better than me I'm sure.

 

Thanks baracis! Any ideas on my gas mileage? Any relationship with the idle issue?

 

Well first of all, welcome to DF!

Do you have an auto or a 6spd? From some of the mpg threads we've had the v6 doesn't seem to do any better than the v8 mileage wise, at least with the auto. The v6 manual guys seem to have better luck, my guess is the weight of the truck plays a hand here as the v8 doesn't have to work as hard to get it moving. 8 minute commute is pretty short, my experience so far is when I'm making very short trips with the truck barely having time to warm up my mileage goes right out the window. Granted I enjoy hearing my exhaust a bit too much but if it's all in town 5-10 min trips I get 9-10mpg.

As far as the shimmy, mine used to do that once in awhile, since I switched to the autolite 3923 plugs it hasn't done it. They're a heat range cooler than stock for the 4.7, on the 3.7 they're actually what Autolite shows for O.E. replacement. Pretty cheap too.

Bouncy front end is thanks to the factory front struts, they're not great. Monroe and Rancho both offer replacements that will get rid of that feeling. I'm actually planning on putting the Rancho's on mine this summer.

 

Thanks for the response Altair!

It's an automatic. I wanted stick, but my wife needs to drive it once in a while to go to IKEA and Home Depot.

So a few followups:

1. Other than taking longer trips, should I just start her up and let her sit for 10 minutes before driving off? Any other tips?

2. There's a chip on ebay (http://tinyurl.com/dbs7s4) that claims a serious boost in horsepower and mpg: Even if the mpg claims are true, a boost in horsepower would be indirectly helpful to gas mileage correct?

3. As for the plugs - I'm changing them first thing tomorrow. I wonder if they'll help my mpg?

Generally speaking, it seems that my experience is much worse than the other city mpg claims on this board. Unless of course "city" driving for everyone else is much more than 10 minute rides.

Thanks Altair. Still welcoming feedback from you other pros as well!

 

Your consumption seems a little high. But the quad cabs are heavier, the 4spd auto isn't helping, and short trips are the worst.

A good once-over can't hurt your MPG and idle; new air filter if it's dirty, new plugs, clean the TB if it's grimy.

Your driving habits are easily the biggest influence. I got over 25 MPG in my truck for a whole tank, but I radically changed the way I drove. Some people aren't aware that they drive with a heavy foot; it doesn't mean they speed, but they accelerate and decelerate too rapidly.

 

changing out the plugs would be the best bet, most if not all were gapped incorrectly, the autolite 3923 plugs are great, i run them because of the nitrous, as for the irractic idle, you may need to change out the tps sensor, they are 106.00 it is a electronic magnet that will hold the idle instead of having go up 1200 rpm than back down to 500 rpm repeating itself, also once this is done, fill up the tank, get on the highway and drive the snot out of it, depending on the mileage it should do very well, and short trips just suck up the gas.

 

Yeah that's a good point, get out and wring it a little bit. A redline a day keeps the carbon away!

 

Somebody no too long ago had a V8 with aweful mileage. 9mpg is really low for the V6They replaced the TPS, IAT, and EGR (or whatever our equivelant is) and that seemed to help. I would also recommend replacing the O2 sensors. If you SeaFoam it, definitely plan on replacing the O2 sensors.

 

I'm honestly not sure if letting it sit and warm up would help or not. Getting out on the highway and opening it up once in awhile is definitely good advice, my aunt had a brand new chevy she only drove 4-6 miles at most and never above 35. Every so often she'd call my grandfather and tell him her car wasn't running good and ask him to take it to the shop for her. He'd go get the car, hop on the turnpike and run it down to the next exit and back, by the time he gave it back to her it was running just fine.

That chip screams scam IMO. Most of the chips on ebay are a resistor in a box, they mention that on their page and try to justify theirs costing more then neglect to prove that theirs isn't just a resistor in a box either. If they do anything at all it's probably the same thing as the powerwire which you can make yourself with a 4.7k ohm resistor. The claims they have on that page are absolutely ridiculous.