Calling all experts and guru's
Thread Starter
Teching In
Joined: Apr 2008
Posts: 13
Likes: 0
No smells and I fill up drive fill up again and calculate miles per gallon
Replace oxygen sensors.
If problem persists inspect fuel pump. I had a pressure line leak in tank and it would cause the fuel pump to stress itself and best I can figure evaporate fuel as it over heated from all the extra work
If problem persists inspect fuel pump. I had a pressure line leak in tank and it would cause the fuel pump to stress itself and best I can figure evaporate fuel as it over heated from all the extra work
Joined: Nov 2001
Posts: 34,632
Likes: 2,557
From: Schiller Park, ILL Member: #317
Not sure how it could be that bad without tripping a MIL and/or having other driveability issues, unless you spend 95% of your time at WOT. Are you sure you don't have a fuel leak somewhere? Otherwise, MAF and/or front O2s need some attention - but the exhaust should smell so rich that you almost can't stand anywhere near it with the engine running.
I don't get much better gas mileage. I had a thread on here when I first bought my car. Mileage was horrific, got about 150 miles per tank. Didn't matter how I drove the car, normally or feather footed. Then one day I got over 200 while hammering it fairly good on a long drive. Makes zero sense. Haven't found an issue. I never drive it so it doesn't bother me.
To those saying BS - nah dude. This **** happens. My car has 30K BTW and is 100% stock except for pulley and lid - with a PAPER filter.
To those saying BS - nah dude. This **** happens. My car has 30K BTW and is 100% stock except for pulley and lid - with a PAPER filter.
Joined: Nov 2001
Posts: 34,632
Likes: 2,557
From: Schiller Park, ILL Member: #317
FWIW, I had no issues getting ~12mpg out of my '00 WS6 with an A4, 3.23s and a 3500 stall TC in city driving. That was not being easy on the throttle either. My stock LS1s have usually gotten 14-16mpg with all city driving, all A4 cars.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Joined: Nov 2001
Posts: 34,632
Likes: 2,557
From: Schiller Park, ILL Member: #317
That doesn't seem very likely based on the details given earlier:
If the cats are clogged bad enough to cause this sort of MPG loss even with ultra-conservative driving, I don't see how the engine could run/feel 100% even at part throttle. But it would be a simple test; the OP could do a WOT run and if the engine pulls strong all the way to redline without any issues, and the cats aren't glowing red after the fact, then his problem likely lies elsewhere.
If the cats are clogged bad enough to cause this sort of MPG loss even with ultra-conservative driving, I don't see how the engine could run/feel 100% even at part throttle. But it would be a simple test; the OP could do a WOT run and if the engine pulls strong all the way to redline without any issues, and the cats aren't glowing red after the fact, then his problem likely lies elsewhere.
TECH Addict
Joined: Mar 2013
Posts: 2,628
Likes: 30
The cats would be toasted by now, they can't handle that much raw fuel for very long. That's why I just don't believe too much of what this dood posted. Plus if its stock it should go into cat protection mode............
Joined: Nov 2001
Posts: 34,632
Likes: 2,557
From: Schiller Park, ILL Member: #317
I still wonder if he doesn't have a fuel leak somewhere, that's the best explanation for a ~5mpg result from super easy driving without any SES light and absolutely zero driveability issues of any kind from idle to WOT.
If I suspected a fuel leak, I would let the car sit somewhere without wind, and run the fuel system to stay on for a while. You would be able to smell the fuel if the leak is significant. I do this test before running an engine after I put it or the fuel system into a car. Make sure to smell everything first before you do the test to ensure the fuel isn't already there (which would still "find" a leak).
Originally Posted by RockinWs6
The cats would be toasted by now, they can't handle that much raw fuel for very long. That's why I just don't believe too much of what this dood posted. Plus if its stock it should go into cat protection mode............
But plugged cars cost me 70+ hp on a dyno a couple years back now. You can definitely feel it
Originally Posted by RPM WS6
I still wonder if he doesn't have a fuel leak somewhere, that's the best explanation for a ~5mpg result from super easy driving without any SES light and absolutely zero driveability issues of any kind from idle to WOT.
Joined: Nov 2001
Posts: 34,632
Likes: 2,557
From: Schiller Park, ILL Member: #317
Maybe a small line leak under pressure, perhaps only during times of heavier fuel flow and maybe not even visible at idle. If none of the scanner data looks out of sorts, it might be worth inspecting the system for any signs of leaks.
You all need a holiday/vacation... You are missing the most obvious thing.
The OP should set up a security camera on the car 24/7 and look out for bums siphoning gas out of the tank.
The OP should set up a security camera on the car 24/7 and look out for bums siphoning gas out of the tank.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Joined: Nov 2001
Posts: 34,632
Likes: 2,557
From: Schiller Park, ILL Member: #317
