hello there

i understand that im in the right place for some quality help, my 1999 e36 316 open air special which i love dearly is suddenly killing me on petrol, no lack of performance of running problems.the car has only 41,000 miles genuine!!!!

begging for help

jamie

not sure at all, could it be one of your sensors?

mine has been drinking a lot of gas lately too :( dont know what it is though!

I'd think if there was sensor issue with these drastic results, you'd get a check engine light. Before I did anything rash, I'd make sure all the basics are done. Air filter, spark plugs, fuel filter, etc. Plugs and fuel filter might still be original @ 41,000 miles. Wouldn't be a bad time to replace them. None of these things really has a huge impact on MPG, but you'll narrow down some items that need to be done about now anyways.

Are your tires inflated properly? Low tires pressures (which happens this time of year) doesn't help.

good call on the cel

Hello,
Does your water temperature rise up to about half way on the gage fairly quickly? If not and it stays low, you need a new thermostat. That was the first thing I noticed on my TI when I got it. Running below operating temperature will affect gas mileage. Also, run some sea foam injector cleaner directly into one of the vacuum lines into the intake. It will clean your injectors and top end. Lastly, change your automatic tranny fluid with a synthetic like Ams-oil or Mobile One.

Doing these things before a trip to Tahoe gave me 33 MPG driving very fast...

all of your re[lys are much appreciated, it does take a while to heat up i must say, so does that make a masiv difference, like half my mpg? really tricky this 1 as theres very little indication of a problem other than my wallet geting burnt everytime i drive

Hey, I get 15mpg, too (after spending a day at the racetrack :devillook ) This drastic amount of change has got to be a sensor issue (which would throw a CEL unless there is a problem with the CEL, too?). O2 sensors are notorious for just this type of symptom....a bad O2 sensor tells the computer to dump more gas into the engine to compensate for what it thinks is a correct reading. RESULT: extremely poor gas mileage...

I bought my '96 TI about 1 1/2 months ago now, it had terrible gas mileage at the time. What I did was drive it like I was babying it and eventually the mileage started to get better. The previous owner may not have driven the car economically. On the first tank of gas I would say the car got about 200 miles before it needed gas again. Now it will probably be about 350 miles per tank.

Since purchasing the car it has had the following done to it:

replace cabin filters
Clean air filter
remove foam from airbox(where air filter sits)
change fuel filter
change oil & oil filter
check tire pressure once a week
clean idle control valve
check air intake rubber parts for leaks
keep heavy items out of car (excluding me of course)
replaced oxygen sensors
reprogrammed DME
drive like an old man

Near term projects:
change auto trans fluid
change differential oil
flush cooling system
change thermostat (think this is a problem based on car's operating tems)

i have a 325i with the same problem..i keep getting an o2 cel code and f#$k its the 5th sensor..still the same result..i tried to change the relay for it with no change..it has to be fuel pressure regulator.holding and dumping fuel..or just dumping. iam also going to bench flow all my injectors too and rebuild em if needed.i have the smell of gas in there around the intake manifold.the o2 is all black when i pull it out. i will let you know if this fixes the problem..