Got a 2003 3.0 Cat that has around 11-12 mpg on the city. Hardly ever go on the highway. I used Plus gasoline. Why am I getting such low mpg. Switched out air filter.. I heard about the Ebrake dragging not sure what to check for... What other things can I check for and I smell either a burning smell from the exhaust from time to time not sure if that has to do with anything. Please help thank you!!!

 

Fuel mileage varies really between models. Also where are based? Is it US or UK/ROW mpg?

 

I’m located in the US

 

First is the check engine light on? If it is have you had the codes read and if so what did they read.
If no check engine light and that kind of gas usage we will need to look at a few things. Unfortunately, you are going to need access to a code reader. We need to no what the STFT (short term fuel trims)and LTFT (long term fuel trims) are. The code reader should give those.
In the mean time there are some things you can visually check and some maintenance you can do.
First get a spray can of MAF sensor cleaner and clean up the MAF Sensor. Get a can of Brake Cleaner, with the engine running spray the brake booster check valve, and around the intake manifold mounting area. Does the engine speed up? If yes you have a vacuum leak. Check the PCV valve hose and make sure you have one with ribs on it. If you don't and it is smooth check for cracks and splits along the bottom.
The last thing is to make sure that while the engine is running and the car is stationary you don't smell or see any fuel leaks.
To check for a sticking park brake you can take the car for a drive and when you return place your hand near the wheels in the rear. If a wheel is to hot to touch the brake is dragging.
Give it a go and get back with us.

 

Where in the US are you located? If it is a colder climate and you make very short drives where the car does not have a chance to full warm up to temperature, that mileage is very plausible and could easily explain the situation

You don't mention if the low mpg is something that has just started or has it always been like that?

The "Plus" gas you use, what is the octane? If that is a mid-grade, you might want to switch to premium, the 91-93 octane, whatever the premium is in your area. That is what is recommended and would give you teh best mpg.

Has any work been done to the car recently or has anything else recently changed on it?

Can you describe the burning smell from the exhaust a little better? Like gas burning or like if something electrical is burning or like rotten eggs?

Like another member said, any type of lights on the dash that could help?

The more infiormation you can give the better the chances of someone being able to point you on the right path.

 

I’m located in Miami, FL Warm Tropical climate. The gas has been like this for a few months I had to fill the tank up soon so I am going to try Premium and I had an engine rebuild to a 3.0 I had a lot of fluids cleaned and Work done to pretty much most of the car except the rear differential...110,000miles and it smells like a burning fuel I’ll try to have the windows down and get a real good description and see what else I can check for and no lights expect Everytime I put the car in reverse I hear a clunk and The car switches off if not warmed up for 2mins

 

Daniel, to check the e-brake for binding, here is the simple test:
-with the car parked, set the e-brake firmly, pulling it up as high as you can.
-release the e-brake
-apply the e-brake again, but this time, see if you can feel drag on the e-brake lever as you start to pull it up and getting progressively harder.

If you have a stuck e-brake lever, what you will feel is the e-brake lever on the second application will be really easy to apply and you will either feel it suddenly engage or you will be able to pull the e-brake up really high and you then hit the limit of travel.

As to figure out how to determine which wheel(s) is having the issue, you will need to remove the rear tires and look at the e-brake lever. It will be the lever that you see a braided cable going to on the top of the caliper. With the car properly blocked and the e-brake released, you should be able to take your thumb and push the lever towards the rear of the car. If you get movement, then you have a sticky e-brake lever. If you can look at both calipers at the same time, you may notice one lever will be pretty much straight up and down while the other one is leaning towards the front of the car. The one leaning forward is your bad caliper. In some cases, you may have both calipers with the levers leaning forward.

Another thing you can try is simply taking the car for a spin around the block after engaging and disengaging the e-brake, getting it up to say 50 mph (or more) for 5 minutes. Then pull into a parking lot at an easy pace and place the back of your hand in one of the openings of the rear wheels. The brakes should be warm. If you are thinking that the brakes would have burnt you, then odds are you are seeing a stuck caliper. You can compare the heat coming off of the rear calipers with the fronts. The fronts should be slightly warmer than the rears.

If you need more info, please let me know. I went around and around with the rear calipers on my X-Type and learned a lot about them. There is even a write up here on how to rebuild the calipers should you be interested. Just a note though, if you are thinking this route, you need to find a 14mm pentasocket (5 pointed socket). Not an easy tool to find.

 

What was the mileage you would get before?