burning more fuel than usual?

ovaltine224 · 01-18-2013, 08:15 AM

I just noticed my cars been burning alot of fuel these past two weeks. The dashboard says im doing about 14mpg.

Here's some recent info:
-In december, I had codes for all four O2 sensors. Mechanic had a hard time figuring out the cause but turns out to be PCV short which I replaced.
-Replaced oil filter gasket
-Oil change
-Vehicle inspection
-Added power steering fluid
-Added window washer fluid
-Added engine coolant (I decided to just add PEAK coolant)

Car was running fine for a few weeks until just now I noticed I started burning more fuel. I just ordered a new air filter hoping that it might help.

Any ideas on cause? Maybe related to the repairs or coolant I added?

ovaltine224 · 01-19-2013, 08:13 PM

Bump

Maybe related to my Mass Air Flow sensor? When I'm just parked in my drive way or in traffic I'm getting around 10 mpg

///M3NACE · 01-19-2013, 08:51 PM

coolant has nothing to do with fuel. My guess its the o2 sensors but you had that replaced. Also 14 is god damn awful I used to get that on a V8. PS fluid? Don't our cars use ATF? Not 100 percent sure but my e30 and e36 was ATF. I found this the hard way on the e30 and put PS fluid and made a very minor leak drips to a puddle.

ovaltine224 · 01-19-2013, 09:54 PM

i didn't replace the O2 sensors. I had codes for them but it was the PVC that caused them. I have no SES codes at the moment.

and my PS takes CHF fluid

any help will be appreciated! Im thinking of just trading in the car cuz its been nothing but repairs the past 2 years!

ovaltine224 · 01-22-2013, 02:42 PM

I forgot to say that I have no check engine lights or anything!

Was weird. When my mechanic fixed the PCV short he said a code came up for the MAF. So I told him to replace that and fix the oil gasket leak. When I picked up my car, the sheet said that a gas test was done and no MAF was put in.

mcpcolas · 01-23-2013, 12:24 AM

Quote:

Originally Posted by ovaltine224

I just noticed my cars been burning alot of fuel these past two weeks. The dashboard says im doing about 14mpg.

Here's some recent info:
-In december, I had codes for all four O2 sensors. Mechanic had a hard time figuring out the cause but turns out to be PCV short which I replaced.
-Replaced oil filter gasket
-Oil change
-Vehicle inspection
-Added power steering fluid
-Added window washer fluid
-Added engine coolant (I decided to just add PEAK coolant)

Car was running fine for a few weeks until just now I noticed I started burning more fuel. I just ordered a new air filter hoping that it might help.

Any ideas on cause? Maybe related to the repairs or coolant I added?

I'm in the same boat as you I'm averaging 10mpg. everytime I take the car to the dealer for that . They keep telling me the engine is running fine there's no code in the dme . My car Is stock

ovaltine224 · 01-23-2013, 11:13 AM

I was doing about 8-10 mpg. So I tried doing the auto tranny reset and now I'm upto about 15mpg. I did order a new air filter and I'm gonna clean the Mass air flow sensor this weekend when I install. Hopefully that helps!

ovaltine224 · 02-14-2013, 04:57 PM

Update:

Installed the air filter but no luck. I'm at 14mpg. I took out and cleaned my vanos solenoids today and noticed something....when my car was parked and I revved the engine, it would rev nice and smooth but when I let go of the gas pedal the needle came down normally except around 1200rpms it feels like the engine hiccups. Tried it a few times and everytime there was a "bump" around 1200rpms when the needle was coming down.

ovaltine224 · 02-19-2013, 10:50 PM

Bump

I'm wondering if I might need a transmission fluid change. Automatic transmission shifts much later than usual. Maybe that's what's causing the bad fuel mileage?

hugus311 · 02-19-2013, 11:10 PM

peak is the wrong color fluid as it should be blue BMW fluid also check your codes even if with a generic obd2 code reader because you might have a p1552 or p 1553 for intake or outake vanos solenoid malfunction as it wont always throw a SES but it will store it. You already cleaned which is good but try also changing your oil and re cleaning solenoids and recheck tire pressures and reset trip computer to recalculate gas

matttcheeww · 02-21-2013, 10:52 PM

maybe try changing your spark plugs?

freshwater · 02-21-2013, 11:07 PM

how many miles you got, may be plugs, injectors or Carbon on intake valves.

ovaltine224 · 02-21-2013, 11:52 PM

I'm at about 97,000 miles right now. I don't rmr correctly but when I bought the car I feel like the car fax stated that the car got new spark plugs at 60k but not sure. I've been meaning to stop by the autostore and check the OBD reader but just haven't had the chance.
I did however have a talk with the mechanic close to my house and he says with spark plugs it's a gradual decrease in mpg instead of overnight but who knows? Lol

ovaltine224 · 02-22-2013, 01:47 PM

Anyone know if a clogged PCV/CCV would damage the spark plugs? And would damaged spark plugs make my car shift late than usual? Just some things I'm pondering. I live in new england so been getting slammed with snow and more coming this weekend so it's hard getting the chance to pull the car out

ovaltine224 · 02-22-2013, 03:05 PM

Update!

So I took my car out today and checked codes and there were no codes. So then I decided to drive it around for awhile since I cleaned my vanos solenoids last week but never drove it to see if it was the case. And guess what??!! My gas usage is back to normal! Getting like 21-23 mpg now! Hopefully it stays like this *knock on wood*

Man I'm so happy now. I was gonna get rid of my bmw cuz of all the problems but now I'm gonna hold on to it a bit longer since it's good!

Thanks everyone!

01-18-2013, 08:15 AM	#1
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	burning more fuel than usual? I just noticed my cars been burning alot of fuel these past two weeks. The dashboard says im doing about 14mpg. Here's some recent info: -In december, I had codes for all four O2 sensors. Mechanic had a hard time figuring out the cause but turns out to be PCV short which I replaced. -Replaced oil filter gasket -Oil change -Vehicle inspection -Added power steering fluid -Added window washer fluid -Added engine coolant (I decided to just add PEAK coolant) Car was running fine for a few weeks until just now I noticed I started burning more fuel. I just ordered a new air filter hoping that it might help. Any ideas on cause? Maybe related to the repairs or coolant I added?
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01-19-2013, 08:13 PM	#2
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	Bump Maybe related to my Mass Air Flow sensor? When I'm just parked in my drive way or in traffic I'm getting around 10 mpg
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01-19-2013, 08:51 PM	#3
///M3NACE Banned 182 Rep 3,900 Posts Drives: E36 M3, E36 Vert , E90 N52 Join Date: Oct 2006 Location: Downers Grove, IL iTrader: (5)	coolant has nothing to do with fuel. My guess its the o2 sensors but you had that replaced. Also 14 is god damn awful I used to get that on a V8. PS fluid? Don't our cars use ATF? Not 100 percent sure but my e30 and e36 was ATF. I found this the hard way on the e30 and put PS fluid and made a very minor leak drips to a puddle.
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01-19-2013, 09:54 PM	#4
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	i didn't replace the O2 sensors. I had codes for them but it was the PVC that caused them. I have no SES codes at the moment. and my PS takes CHF fluid any help will be appreciated! Im thinking of just trading in the car cuz its been nothing but repairs the past 2 years!
	Appreciate 0 Quote

01-22-2013, 02:42 PM	#5
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	I forgot to say that I have no check engine lights or anything! Was weird. When my mechanic fixed the PCV short he said a code came up for the MAF. So I told him to replace that and fix the oil gasket leak. When I picked up my car, the sheet said that a gas test was done and no MAF was put in.
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01-23-2013, 11:13 AM	#7
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	I was doing about 8-10 mpg. So I tried doing the auto tranny reset and now I'm upto about 15mpg. I did order a new air filter and I'm gonna clean the Mass air flow sensor this weekend when I install. Hopefully that helps!
	Appreciate 0 Quote

02-14-2013, 04:57 PM	#8
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	Update: Installed the air filter but no luck. I'm at 14mpg. I took out and cleaned my vanos solenoids today and noticed something....when my car was parked and I revved the engine, it would rev nice and smooth but when I let go of the gas pedal the needle came down normally except around 1200rpms it feels like the engine hiccups. Tried it a few times and everytime there was a "bump" around 1200rpms when the needle was coming down.
	Appreciate 0 Quote

02-19-2013, 10:50 PM	#9
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	Bump I'm wondering if I might need a transmission fluid change. Automatic transmission shifts much later than usual. Maybe that's what's causing the bad fuel mileage?
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02-19-2013, 11:10 PM	#10
hugus311 Titanium silver + Sport + Premium 32 Rep 662 Posts Drives: 2006 330i (E90) Join Date: Nov 2009 Location: west covina 626 iTrader: (6)	peak is the wrong color fluid as it should be blue BMW fluid also check your codes even if with a generic obd2 code reader because you might have a p1552 or p 1553 for intake or outake vanos solenoid malfunction as it wont always throw a SES but it will store it. You already cleaned which is good but try also changing your oil and re cleaning solenoids and recheck tire pressures and reset trip computer to recalculate gas
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02-21-2013, 10:52 PM	#11
matttcheeww Registered 0 Rep 2 Posts Drives: 2006 BMW 325i Join Date: Jan 2013 Location: San Diego iTrader: (0)	maybe try changing your spark plugs?
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02-21-2013, 11:07 PM	#12
freshwater Private First Class 11 Rep 156 Posts Drives: 2007 335i Jet Black Sports pkg Join Date: Mar 2010 Location: USA iTrader: (0)	how many miles you got, may be plugs, injectors or Carbon on intake valves. __________________ 2007 X5 4.8 \| Sport pkg \| ZPP \| ZCW \| ZPS \| ZTP \| 3rd Row Seat \| Entertainment pkg \| HUD \| Jet Black \|Continental Extreme DWS.
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02-21-2013, 11:52 PM	#13
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	I'm at about 97,000 miles right now. I don't rmr correctly but when I bought the car I feel like the car fax stated that the car got new spark plugs at 60k but not sure. I've been meaning to stop by the autostore and check the OBD reader but just haven't had the chance. I did however have a talk with the mechanic close to my house and he says with spark plugs it's a gradual decrease in mpg instead of overnight but who knows? Lol
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02-22-2013, 01:47 PM	#14
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	Anyone know if a clogged PCV/CCV would damage the spark plugs? And would damaged spark plugs make my car shift late than usual? Just some things I'm pondering. I live in new england so been getting slammed with snow and more coming this weekend so it's hard getting the chance to pull the car out
	Appreciate 0 Quote

02-22-2013, 03:05 PM	#15
ovaltine224 swagger jacker 14 Rep 65 Posts Drives: 328xi Join Date: Aug 2011 Location: United States iTrader: (0)	Update! So I took my car out today and checked codes and there were no codes. So then I decided to drive it around for awhile since I cleaned my vanos solenoids last week but never drove it to see if it was the case. And guess what??!! My gas usage is back to normal! Getting like 21-23 mpg now! Hopefully it stays like this knock on wood Man I'm so happy now. I was gonna get rid of my bmw cuz of all the problems but now I'm gonna hold on to it a bit longer since it's good! Thanks everyone!
	Appreciate 0 Quote