Very poor gas mileage, 07 3.5 AWD
 

Hello all, been awhile.

2007 VUE, 3.5 AWD 220k on the clock. Not so long since plugs changed, well under recommended interval.

Runs well, seemingly. Recently changed oil and replaced the coolant temp sensor as it had failed and spiked the gage to trigger the overheat indicator. Hoped that was the cause of decreasing mileage but apparently it wasn’t. No stored codes, no active MIL. Mileage has cratered down to about 14-15 highway. I’m a little stumped.

Anybody have any ideas?

Re: Very poor gas mileage, 07 3.5 AWD
 

...Have the o2 sensors checked, depending on miles on vehicle, also which plugs you used, if not the factory plugs, i would get them, check coils ,if they are making solid contact with plugs, just some thoughts, DC.

Re: Very poor gas mileage, 07 3.5 AWD
 

Maybe the injectors?

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=Vue6;2369922]...Have the o2 sensors checked, depending on miles on vehicle, also which plugs you used, if not the factory plugs, i would get them, check coils ,if they are making solid contact with plugs, just some thoughts, DC.[/QUOTE]

DC: 200k-plus on the engine.

I’ve considered plugs, coils but no misfire codes. Ever. No O2 codes. I get the feeling I’m going to have to start with a new tune-up, O2s all-round and if that doesn’t work…

[QUOTE=SL2 Ride]Maybe the injectors?[/quote]

Maybe the injectors.

Far2Grumpy’s been trying to help me as well, and it’s got us both stumped.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=What a VUE;2371265]DC: 200k-plus on the engine.

I’ve considered plugs, coils but no misfire codes. Ever. No O2 codes. I get the feeling I’m going to have to start with a new tune-up, O2s all-round and if that doesn’t work…



Maybe the injectors.

Far2Grumpy’s been trying to help me as well, and it’s got us both stumped.[/QUOTE]

what have you checked so far?

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=SL2 Ride;2371582]what have you checked so far?[/QUOTE]

Everything I mentioned. It’s driving me nuts.

No codes. Of any kind. No misfires. No vacuum leaks, no plugged exhaust. Runs smooth and idles smooth. I’m completely stumped.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=What a VUE;2371588]Everything I mentioned. It’s driving me nuts.

No codes. Of any kind. No misfires. No vacuum leaks, no plugged exhaust. Runs smooth and idles smooth. I’m completely stumped.[/QUOTE]

Well injectors aren't the worst thing to replace...

Well what's the cost of the O2 sensors vs swapping out the injectors?

Oh, and fdryer says to check the external fuel filter.

[url]http://www.saturnfans.com/forums/showthread.php?t=235861[/url]

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=SL2 Ride;2371589]Well injectors aren't the worst thing to replace...

Well what's the cost of the O2 sensors vs swapping out the injectors?

Oh, and fdryer says to check the external fuel filter.

[url]http://www.saturnfans.com/forums/showthread.php?t=235861[/url][/QUOTE]

Until he didn't.

I thought of that as well, but realized after scooting under there - they weren't there.

Re: Very poor gas mileage, 07 3.5 AWD
 

Swollen front brake caliper hose?? Just throwing out there as a possibility since there are no codes being set. Does it feel an little sluggish? Check and see how hot the rotors are, unless you are doing frequent, hard stops the calipers should be warm to the touch not super hot.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=newbievueowner;2372162]Swollen front brake caliper hose?? Just throwing out there as a possibility since there are no codes being set. Does it feel an little sluggish? Check and see how hot the rotors are, unless you are doing frequent, hard stops the calipers should be warm to the touch not super hot.[/QUOTE]

Brakes are new and fine. Problem pre-dated the brake job as well.

Not sluggish at all, no stumbles, no nothing. That’s what makes this so hard to dx.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=What a VUE;2372173]Brakes are new and fine. Problem pre-dated the brake job as well.

Not sluggish at all, no stumbles, no nothing. That’s what makes this so hard to dx.[/QUOTE]

Not sure if maybe you misunderstood what I said or whether I missed something in what you might have mentioned. So you have had the front brake caliper hoses changed? On these Vues, the front brake line getting pinched off due to rust on the bracket that holds the hose is VERY common, especially if you live in an area that gets salt put on the roads on the winter. I've had to do them on both the Vue's I owned in the past. Was just a thought/area to look at as you are not getting any DTC's and really crappy fuel economy.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=newbievueowner;2372177]Not sure if maybe you misunderstood what I said or whether I missed something in what you might have mentioned. So you have had the front brake caliper hoses changed? On these Vues, the front brake line getting pinched off due to rust on the bracket that holds the hose is VERY common, especially if you live in an area that gets salt put on the roads on the winter. I've had to do them on both the Vue's I owned in the past. Was just a thought/area to look at as you are not getting any DTC's and really crappy fuel economy.[/QUOTE]

Understood perfectly. As I said, brakes are new, includes hoses.

Re: Very poor gas mileage, 07 3.5 AWD
 

Ok, I have no other idea then at this point.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=newbievueowner;2372186]Ok, I have no other idea then at this point.[/QUOTE]

Welcome to the club. 😑

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=What a VUE;2372194]Welcome to the club. 😑[/QUOTE]

I'm wondering if you ever solved your low fuel mileage.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=SL2 Ride;2373637]I'm wondering if you ever solved your low fuel mileage.[/QUOTE]

I have not. Haven't been driving it as a result.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=What a VUE;2375468]I have not. Haven't been driving it as a result.[/QUOTE]

Did you ever swap out the injectors? I have to wonder if worn injectors couldnt be dumping more gas in the cylinders.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=SL2 Ride;2375533]Did you ever swap out the injectors? I have to wonder if worn injectors couldnt be dumping more gas in the cylinders.[/QUOTE]

I haven't yet. Going to start with obvious, basic fixes. Plugs, coils, filters, O2 both upstream and downstream.

Started thinking about this again the other day, wondered if a bad EGR could be
causing issues? Also, Honda is now recommending 0-20 synthoil, and that's what the tech has been using for some time. I'm also wondering if the thinner oil is contributing to the problem.

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=What a VUE;2375592]I haven't yet. Going to start with obvious, basic fixes. Plugs, coils, filters, O2 both upstream and downstream.

Started thinking about this again the other day, wondered if a bad EGR could be
causing issues? Also, Honda is now recommending 0-20 synthoil, and that's what the tech has been using for some time. I'm also wondering if the thinner oil is contributing to the problem.[/QUOTE]

Wouldn't a bad egr or 02 sensor throw a code?

Re: Very poor gas mileage, 07 3.5 AWD
 

[QUOTE=SL2 Ride;2375595]Wouldn't a bad egr or 02 sensor throw a code?[/QUOTE]

You'd think so. But no codes, no nothing.

Re: Very poor gas mileage, 07 3.5 AWD
 

You need to look at live data and check on your o2 sensors and fuel trims.