Page 1 of 1

19.2 mpg!

Posted: Wed Aug 20, 2008 7:05 pm
by richg40
That's as good as it gets for my 320i, and I know that cant be normal.

I cant find any air leaks, the car idles and drives literally like new. But, the temp gauge only ever goes up to 1/4. Just replaced the thermostat this second and still only goes up to a 1/4. Is it feasible that both temp sensors have failed? It's costing me fortune.

I replaced the head gasket about 4 months or so ago, replaced every gasket on the top end. Also put a 325i throttle body on there. Had the head skimmed. How much do you think this will affect the CO?


Rich.

Re: 19.2 mpg!

Posted: Wed Aug 20, 2008 7:23 pm
by siddiqi1
you havent checked the most imp thing yet; the BLUE TEMP SENDER; it does decide your cold fueling so could be that you know!

also have the CO chekced and adjusted if reuiqd by a garages EXHASUT TESTING THING via the AFM!

maybe your timings not spot on?

Re: 19.2 mpg!

Posted: Wed Aug 20, 2008 8:28 pm
by doughboy
How are you getting that figure? OBC reading.

If yes, is it reading mpg or m/g? afaik m/g is correct for UK. I changed that and saw a leap of 18mpg to a HUGE 22.5

Re: 19.2 mpg!

Posted: Wed Aug 20, 2008 10:12 pm
by richg40
Im intending to change the temp sensors now to see what happens. I'll try the OBC thing but I know the mpg is damn low because im literally getting 35 miles out of a 1/4 of a tank.

Re: 19.2 mpg!

Posted: Wed Aug 20, 2008 10:34 pm
by Brianmoooore
Don't start changing parts at random!
Take off the panel above the drivers legs, and unlatch the connector from the engine ECU. (You may have to unbolt the ECU to do this).
Assuming this 320 is sufficiently modern to have a 55 pin ECU, measure the resistance between pin 45 and earth (ECU bracket). It should be around 4000 ohms with the engine stone cold.
Next, plug the ECU back in, and warm the engine up. Take the ECU plug off again, and measure the resistance with the engine at full working temperature. Should be around 300 ohms.