I bought a 1999 Dodge Ram 2500 with extended cab long bed with the 5.9l gas engine. Its lifted 4in with 33's. I did plug wires, water pump, coolant bypass hose, oil, oil filter, cap, and rotor on distributor. Cant get the spark plugs tho. Dumped some sea foam in the gas tank. It has an exhaust leak therefore it ticks. planning on getting some shorty headers to fix that. The problem is I'm constantly getting 7.0-7.5mpg. even when I'm not getting on it. Does anyone else have this problem? Or have some solutions to gettin some better gas mileage?

 

Check to see if you have a blown plenum gasket. See the sticky thread on the plenum issue for complete information.


Also, why can't you change the spark plugs?

 

Your driving a lifted ram 2500.. Did ya expect good mileage? :P

If the exhaust is leaking at the manifolds this will be part of the reason for the poor mileage, if not most of it. I would also suggest looking at the plenum. Sadly, you are not too far off from the expected mileage with your truck. You should see anywhere from 9-12mpg with your setup.

 

I could not get them out due to the heat sheilds around them.. They are wrinkled and im unable to get my tools in there to get them out. But how do i check for to see if the gasket has been blown?

 

Take a flashlight, open up the throttle body and look down through it. If you see oil coating the floor of the plenum, it's likely history.


To get those spark plugs changed, take some good pliers and ****** out those spark plug heat shields! They serve no true purpose and are pressed into the cylinder heads. Once those are removed, throw them in the trash and you will have all the room you need to remove the spark plugs.

 

Thats about what I get in my 95 2500 but my plenum is blown so I'm assuming thats killing it a lot. I will hopefully be replacing it soon after it warms up a bit If your plenum is blown your o2 sensor and cat are probably getting bad as well. Read the plenum sticky, good luck!

 

With my truck, (2500, but, not lifted...) I can get 12 or so around town, and 15-18 on the highway. My guess is, your plenum is blown, front O2 sensor is getting lazy, (and exhaust leaks sure don't help there) and your cat is probably plugging up. If it is even still there. If you are over 100K miles, do the timing chain and gears when you do the plenum.

 

Use the search function. Comes in handy when searching for threads on common problems.

https://dodgeforum.com/forum/2nd-gen...um-thread.html

 

I read the threads about it. Once it gets a little warmer imma take a look at it, but since my check engine light came on for my cat and o2 sensors. I do believe it is a blown Plenum. Im workin on getting all new items. The intake manifold, Headers, High flow cat, throttle body spacer, cold air and re-gear it. To get some of that money i keep throwin in it for 7mpg.. but for mean time imma drive my ****ty ford and wait for warmer weather. If i need advice ill post up here.

 

Skip the throttle body spacer. Spend the money on something else that actually DOES something. TB spacers don't do a damn thing on our trucks, no matter what claims people make.