Worse and worse gas mileage...
02-10-2009, 11:01 PM
#21
I didn't read everything here, so.......
Do the Sea Foam, it can't hurt anything. Change the fuel filter afterwards. 1 full can through 3/4 tank of gas. I've been doing this every 3 months for 11 years, its fine. Sea Foam the top end too, your ready with that mileage.
You could be having hard starts because of leaking fuel injectors......so do the pressure test and watch it after you shut the engine off to see if it dies off quick.
Also, Bosch 02 sensors are garbage...for some cars. They simply do not work in my car, it won't run. Some people I know have minor problems, some have bad problems. Get AC Delco sensors from the dealer. Some things should only be factory original parts.
www.rockauto.com has good prices for brand new ones.
.
Do the Sea Foam, it can't hurt anything. Change the fuel filter afterwards. 1 full can through 3/4 tank of gas. I've been doing this every 3 months for 11 years, its fine. Sea Foam the top end too, your ready with that mileage.
You could be having hard starts because of leaking fuel injectors......so do the pressure test and watch it after you shut the engine off to see if it dies off quick.
Also, Bosch 02 sensors are garbage...for some cars. They simply do not work in my car, it won't run. Some people I know have minor problems, some have bad problems. Get AC Delco sensors from the dealer. Some things should only be factory original parts.
www.rockauto.com has good prices for brand new ones.
.
Last edited by LS6427; 02-11-2009 at 12:28 AM.
02-11-2009, 10:23 AM
#22
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Carbon deposits may be a part of it, but I doubt that would account for all of your mileage loss. I did a CarbonClean treatment on my car (similar effect as a SeaFoam treatment) and I got 3-4 mpg back.
After going through that, I only fill up with top tier gas now: http://www.toptiergas.com/ (ExxonMobil still isn't with "the program")
After going through that, I only fill up with top tier gas now: http://www.toptiergas.com/ (ExxonMobil still isn't with "the program")
Yeah i know exxon isn't a "toptier" gas distributor but we get a discount their so that's why i buy it lol. Plus it's still pretty good gas, and they get a lot of business so their tanks shouldn't ever really have old gas in them.
02-11-2009, 11:14 AM
#23
I really can't believe nobody on here has recommended for you to clean your MAF. That should be the first thing to look at
A $4 can of electronic parts cleaner and 10 minutes. Don't touch anything but the housing and spray the inside real well especially the fine little wire.
A $4 can of electronic parts cleaner and 10 minutes. Don't touch anything but the housing and spray the inside real well especially the fine little wire.
02-11-2009, 12:19 PM
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I really can't believe nobody on here has recommended for you to clean your MAF. That should be the first thing to look at
A $4 can of electronic parts cleaner and 10 minutes. Don't touch anything but the housing and spray the inside real well especially the fine little wire.
A $4 can of electronic parts cleaner and 10 minutes. Don't touch anything but the housing and spray the inside real well especially the fine little wire.
02-11-2009, 01:04 PM
#25
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Mine sucks too. 50 miles for each mark on the fuel gauge. Averages around 190-200 miles per tank. 01 SS 6-speed with 118k miles. I did a Seafoam to it a while ago then did a complete filter change. Might be time to let a shop check it out.
02-11-2009, 10:19 PM
#28
Okay ill look into the carbonclean treatment and check out my fuel pressure.
Yeah i know exxon isn't a "toptier" gas distributor but we get a discount their so that's why i buy it lol. Plus it's still pretty good gas, and they get a lot of business so their tanks shouldn't ever really have old gas in them.
Yeah i know exxon isn't a "toptier" gas distributor but we get a discount their so that's why i buy it lol. Plus it's still pretty good gas, and they get a lot of business so their tanks shouldn't ever really have old gas in them.
One could use a regular gasoline and add Techron or other cleaners at each fill-up, but that gets expensive real quick.
02-11-2009, 11:26 PM
#29
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Top Tier isn't about old or "bad" gas. Gas is Gas. The thing that sets brands apart is the type and concentrations of detergents and other chemicals that keep engines in good working order. Brands that aren't listed are skimping on these additives - which can lead to carbon build-up.
One could use a regular gasoline and add Techron or other cleaners at each fill-up, but that gets expensive real quick.
One could use a regular gasoline and add Techron or other cleaners at each fill-up, but that gets expensive real quick.
I think im gonna run a can of seafoam through the tank next fill up.
I did however fill up after driving for 37 miles, and i calculated the mileage only to find that i got 11.4mpg!!!!!!!!! Terrible!!!!!!!!!!!!!
02-13-2009, 03:36 PM
#31
Winter gas is worse, though less so in Texas.
Change your fuel filter every year/15k miles.
Seafoam/do a professional injector and top end cleaning. Tank treatments are great for prevention but do not clean. If your engine's not running off a cleaning mix, it's not a thorough cleaning.
Clean air filter and MAF.
Use Delco plugs, wires, and O2s.
Tune (which you said you have), make sure they didn't disable some O2 or lean codes. This could be masking a problem.
Check for vacuum and exhaust leaks including at your intake/lid, this could be contributing big time.
After 4 years in service at a chevy dealer, biggest problem with MPG and idle was BY FAR, dirty injectors. This was on all cars, LS included. I mean 90-95% of the time, injector cleaning and fuel filter fixed it. This is the case at BMW, Honda, Mecerdes, etc. too. As mentioned, use the TopTier gas and this problem will be far less frequent.
Change your fuel filter every year/15k miles.
Seafoam/do a professional injector and top end cleaning. Tank treatments are great for prevention but do not clean. If your engine's not running off a cleaning mix, it's not a thorough cleaning.
Clean air filter and MAF.
Use Delco plugs, wires, and O2s.
Tune (which you said you have), make sure they didn't disable some O2 or lean codes. This could be masking a problem.
Check for vacuum and exhaust leaks including at your intake/lid, this could be contributing big time.
After 4 years in service at a chevy dealer, biggest problem with MPG and idle was BY FAR, dirty injectors. This was on all cars, LS included. I mean 90-95% of the time, injector cleaning and fuel filter fixed it. This is the case at BMW, Honda, Mecerdes, etc. too. As mentioned, use the TopTier gas and this problem will be far less frequent.
