Gas Mileage has dropped

[ClassyIrish]

Last fuel up, I got only 11 mpg, before that 25mpg. Same station, Octane is 91 as I have Turbo. No CEL lights. Thought I might have accidentally hit the trip when dusting, but, same thing next fuel up. 11 mpg. Tire's are filled with Nitro, so should not have issues with pressure. I do not smell gas or see anywhere on garage floor where there may be a leak. The only thing different that I HAVE noticed is when I start it up, it has a high 'whirring' sound, like a plane engine almost, just not as loud.

Any idea's?

[MyOtherRidesAVette]

You sure someone's not stealing your gas? Maybe the station where you get gas needs to calibrate their pumps. Short of a major leak, gas tank, fuel line... it sould be running so rich, it shouldn't even be firing; billowing clouds of black smoke, black soot all over the exhaust and back end, etc, etc. And codes being thrown big time. Not a clue...

MORAV

[billymade]

There are a number of things I have noticed on my beetle that have improved gas mileage (after it seemed to use more gas), as my car has gotten more zeros on it.:

1. new and or the latest coil packs (recall)
2. new fuel filter
3. new temp sensor
4. cleaning throttle body/sensors
5. 02 sensor

All of these are maintenance items; they degrade over time... testing can confirm whether they need replaced; mileage is also a way to know if they should be changed (fuel filter, spark plugs, air filter etc.).

Many of these can be done yourself; if you don't feel comfortable doing this... take it to a competent vw shop to have your car evaluated or repaired. Good luck!

PS: how many miles on your car; what kind of tune up or parts have been replaced over the years?

[MyOtherRidesAVette]

Originally Posted by billymade

There are a number of things I have noticed on my beetle that have improved gas mileage (after it seemed to use more gas), as my car has gotten more zeros on it.:

1. new and or the latest coil packs (recall)
2. new fuel filter
3. new temp sensor
4. cleaning throttle body/sensors
5. 02 sensor

All of these are maintenance items; they degrade over time... testing can confirm whether they need replaced; mileage is also a way to know if they should be changed (fuel filter, spark plugs, air filter etc.).

Many of these can be done yourself; if you don't feel comfortable doing this... take it to a competent vw shop to have your car evaluated or repaired. Good luck!

PS: how many miles on your car; what kind of tune up or parts have been replaced over the years?

Not, better than doubling gas consumption, between two fill-ups. "25 mpg - 11 mpg, overnight"

[ClassyIrish]

The tank locks, it is only outside when at work, garage the rest of the time. I am going to give the repair shop garage a call sometime today and see if I can't bring it in. It has 120,000 on it. 2004. Bought used in July. Lots of CEL lights when I first got it. oil change, done, tune up, done, air filter changed, done. Took it to an import garage, they did all sorts of tests, could find nothing wrong, cleared all the codes. Now from 25 mpg to 11 mpg. Don't know if something went array whilst in the garage, but it is awfully odd. She runs really well, no black smoke, no missing, no hard starts, everything seems to be running fine EXCEPT the mpg is so off. I might fuel up at a different station next time, to see if the pumps at my usual place is off, but I don't think so. My gauge is at 3/4 tank with 40 miles on the trip, that is odd also. usually closer to 100 or more. Things that make me go hmmmmmmmm.

[MyOtherRidesAVette]

I was kidding about the station. Lots of them play with their pumps, but not that bad. Besides, you'd notice being charged for double the gas that your tank holds.

[leopardqueen]

I seem to have the same problem u r having. I have a 2004 1.8T with about 63,000 miles on it. Bought new. My check engine light is on again after having it repaired multiple times. I'm wondering if my spark plugs need to be replaced and im not sure when they where changed or how to tell to change them. I dont exactly have the money to be fixing every little thing wrong with my car, but i would like my gas mileage to be better. IF you figure it out, let me know. One day ill bring it in for an extensive diagnostic run to my mechanic.

[Smileybug]

What code is being thrown from your CEL and what has been done so far?

[MyOtherRidesAVette]

Originally Posted by leopardqueen

I seem to have the same problem u r having. I have a 2004 1.8T with about 63,000 miles on it. Bought new. My check engine light is on again after having it repaired multiple times. I'm wondering if my spark plugs need to be replaced and im not sure when they where changed or how to tell to change them. I dont exactly have the money to be fixing every little thing wrong with my car, but i would like my gas mileage to be better. IF you figure it out, let me know. One day ill bring it in for an extensive diagnostic run to my mechanic.

We could offer some advice if we knew what the codes are, and you can get many of them by going to Advanced Auto Parts (I like them) or many Corner Auto Parts Store). If your mpg has been halved, with the price of fuel, your throwing lots of repair money away weekly, unless of course your an old lady who only uses the car to go to church on Sunday!

M.

[ClassyIrish]

They seem to think it is the Mass Air Sensor? They put in one that throws codes but, they say is good, for free, for me to check mileage again. If mileage goes up, they will order new one and install, if not, they will continue to look.

Will let you know what is up at the end of next week. Thanks for all your help

[IndyTom]

Originally Posted by ClassyIrish

They seem to think it is the Mass Air Sensor? They put in one that throws codes but, they say is good, for free, for me to check mileage again. If mileage goes up, they will order new one and install, if not, they will continue to look.

Will let you know what is up at the end of next week. Thanks for all your help

So they replaced the MAF Sensor with another sensor that throws codes? That doesn't make any sense. They probably put in a spare sensor that they had laying around from who knows what kind of VW or Audi. That sensor may not even be calibrated for your particular car. No wonder you are getting the gas mileage of a 67 Cadilac. And I am not sure you are calculating the gas mileage correctly. If your car is running and doesn't show any signs of burning huge and I mean huge amount of fuel without smell or hesitation then something can't be right with your calculating the proper gas mileage. Heck, a Hummer gets better gas mileage than your Beatle. I can see it dropping from 25 to maybe 20 which would be plausible but from 25 to 11 that is just unbelievable.
Did you pull your plugs to see if they are fouled? I would get with someone that has a Vag com and have it properly scanned to see what type of codes come up and go from there. It seems this shop you are taking it to is fishing at best and that can nickle and dime you to death really quick without really addressing the actual problem.
My 00 Beetle has 160+ k Miles on it and gets an average of 24.6 mpg. On longer highway trips close to 29.2 mpg. If it would ever go to 11 mpg I would trade it for an Escalade.

[ClassyIrish]

MAS! They ordered one for me, will have it installed Monday.

They have checked everything, she purrs like a kitten, MAS will make it all good.

[IndyTom]

Originally Posted by ClassyIrish

MAS! They ordered one for me, will have it installed Monday.

They have checked everything, she purrs like a kitten, MAS will make it all good.

Too many people blame things on the Mass Airflow Sensor. Sure it can go out but so can numerous other things. I would have them check for leaks in the fuel line or fuel filter. Perhaps it only leaks when it's under pressure or load and that's why you can't detect any leaks but I would think you should still be able to smell it. A clogged Catalytic converter could cause issues as well as faulty O2 sensors. Good luck to you. I seriously hope that a new MAF sensor will solve all your problems but I have my doubts.

[ClassyIrish]

They ran all sorts of problem solving tests, that is why they put in the MAS. It is back up to good fuel milage now.

This garage is a good group of folks. They don't charge an arm nor a leg. They diagnos, and instead of installing new parts, they replace like they did with my MAS at no charge to see if it is the problem before having the customer throw money at parts. I like that.

It is all good now, other than I just spent 2 hours changing the driver side headlight bulb, Now on to figuring out why my taillight goes out when the brakes are applied. AND now brake light.

Thanks for all the advice, very much appreciated.

[IndyTom]

Glad that you are almost back to normal. Hope you figure out your tail light issue. Perhaps it is a feature you weren't aware off before. Your beetle tries to get the attention of a cute female in the back by turning off the tail and brakelights. When she runs into your rear the mission is accomplished and you can really say that you met by accident. Just make sure it is a cute female before applying brakes. You don't want to end up with Big Bertha

[MyOtherRidesAVette]

Originally Posted by IndyTom

Glad that you are almost back to normal. Hope you figure out your tail light issue. Perhaps it is a feature you weren't aware off before. Your beetle tries to get the attention of a cute female in the back by turning off the tail and brakelights. When she runs into your rear the mission is accomplished and you can really say that you met by accident. Just make sure it is a cute female before applying brakes. You don't want to end up with Big Bertha

Seriously, indication of a bad ground. Check the "spring" connections in the bulb socket, maybe pry up on them a little.

[ClassyIrish]

IndyTom, thinkin it is a winkin, but would rather have a male run into me instead of female, being I AM a female. LOL

Changed the bulb, worked, rode around a bit, now not working. Thinking something is up. Will try your idea of the spring. Wiring that I can see all looks good. May have to get underneath the thing and trace the wires.

Thanks

[IndyTom]

Originally Posted by ClassyIrish

IndyTom, thinkin it is a winkin, but would rather have a male run into me instead of female, being I AM a female. LOL

Thanks

Heck, in that case let me run into you

[ClassyIrish]

Originally Posted by IndyTom

Heck, in that case let me run into you

not in me BughZ! LOL!

I am going to try tightening the 'clips' inside of the socket, see if that works.

What I am 'noticing' about the light: I change the bulb, it works in the garage, I drive it, It stops working. Brake light that is. tail light stays on, good, but when the brake filament takes over, the light goes off. No problem with the turn signal bulb. Filament looks good in the tail/brake bulb when out and looking at it visually, but I understand that there are 2 inside the bulb, one for tail, one for brake. Thinking it wouldn't be the 'clips' inside the socket, cuz the bulb would go completely out, wouldn't it? So logically, seems that something is causing the brake filament to burn out in a very very short time.

Going to crawl under and see if I can see the wiring harness, Or should I tear apart the trunk instead?

:calvin

[IndyTom]

Perhaps it is your brake light switch. There has been a major recall at one time regarding the brakelight switch by VW.
Volkswagen recalls nearly 800,000 cars - Feb. 26, 2007

Perhaps it's worth a try to swap out the switch and see if that solves your problem.