97 960 Struggling Fuel Economy

mydamnvolvo · Post by **mydamnvolvo** » 17 Jan 2016, 13:34

Hi, Cynthia again. Ever since I first started driving my Volvo 960 wagon, I've noticed that my fuel economy has suffered from the estimated 18-22mpg to 10-12.5mpg. Now, my commute is only at most 7 minutes, so I don't really need a whole lot of gas to get to work and back but when I go on 100 mile trips for work, my gas gage drops to about half a tank. I figure it may be a malfunctioning gas gage, but one look at how black my exhaust is shows that I am burning too much gasoline. Out of the WSE transmission settings I always have it in E (ECO) and never really use any heat or A/C for more than 5 minutes. I have inquired before about my EGR valve but I am afraid to open it up and mechanics are shooing me away. I have never really worked on a Volvo engine so I am at a loss. I want to get at least 16mpg out of it to match my Chrysler minivan. Does anyone have an explanation? Thanks again!

-Cynthia

harryhendo · Post by **harryhendo** » 18 Jan 2016, 10:12

Do you have any codes stored in the onboard diagnostics computer? That would be the first place to look for a clue. If you see something like "mixture too rich", it could be any number of issues, from failing fuel injectors, failed sensors, etc.

lummert · Post by **lummert** » 18 Jan 2016, 16:21

I'd suggest diagnosing the oxygen sensor, the engine temperature sensor, or fuel pressure regulator.

Post by **benpineapple** » 19 Jan 2016, 09:07

Yeah, if I were you I'd check O2 sensor, engine temp sensor, condition of injectors, air filter, condition of catalytic converter, vacuum leaks, leaks of any kind. There are a lot of small things that can all add up to dumpy fuel economy. Any engine codes? That might narrow things down if so.

mydamnvolvo · Post by **mydamnvolvo** » 28 Jan 2016, 17:17

Hey everyone,
I drove to a doctor's appointment a few days ago and when I came out the car wouldn't start. This was after the engine was racing after I put the car in park. I got it started and the check engine light as well as the transmission light came on as drove home to diagnose a faulty coolant temp sensor. Now, I am getting about 15ish mpg but I'll wait until the winter gas is done with to complain. Thanks!

93Regina · Post by **93Regina** » 04 Feb 2016, 10:52

mydamnvolvo wrote:Volvo 960 wagon...fuel economy has suffered from the estimated 18-22mpg to 10-12.5mpg.

Airbox thermostat failure...

I have no idea how later day 960s work, but for

Volvo 240 air box thermostat and hot/cold air flapper

960orbust · Post by **960orbust** » 15 Feb 2016, 17:39

mydamnvolvo wrote:Hey everyone,
I drove to a doctor's appointment a few days ago and when I came out the car wouldn't start. This was after the engine was racing after I put the car in park. I got it started and the check engine light as well as the transmission light came on as drove home to diagnose a faulty coolant temp sensor. Now, I am getting about 15ish mpg but I'll wait until the winter gas is done with to complain. Thanks!

We haven't heard from you, Cynthia, how's the car? Situation resolved?

mydamnvolvo · Post by **mydamnvolvo** » 18 Feb 2016, 23:29

So, I took my car on its first 100+ mile journey on Saturday. For 130 miles it used a little more than a third of a tank of gas, which is about 7 gallons. That is about 16 mpg, still a little lower than what I wanted, but, meh. It still has a little wiggly idle that I never looked into and every once in a while it will start to surge and the temp gage will fluctuate, but I use this car for my 4 minute commute, so it's not really being used for more than 15 miles a day. However, it does get better gas mileage in the city than on the highway. I was tempted to try sport mode for the first time on Saturday, but I resisted. Since I live in NY, I got stuck once in the snow, but after using the weather mode button, I got some more traction and backed right out with my rear wheel drive. Thanks, but does anyone know why it gets more city than highway? I think when it gets too hot it tries to warm itself up and uses more fuel because of that ECT sensor that I have to change. Thank You!! <3

mydamnvolvo · Post by **mydamnvolvo** » 23 Feb 2016, 16:48

I meant better highway mileage than on the city. I took it on another trip and averaged about 16-18mpg.