When driving down the highway at 60mph or faster, with the haed lights on. We roll down the drivers window, the hatch light comes on the fuel guage goes to empty causing the fuel light to come on and the van acts like its out of fuel. Any suggestions are very well appreciated.

while manufacturers use the advertised economy figures for sales, testing by reputable auto mobile organizations report that the figures are unrealistic and are generated in perfect conditions in shop
They seldom say real driving conditions just what was achieved in testing
If you are getting 8/100 suburban and better on highway then the economy is good
however it is to be understood that tire widths , pressures , loads , road conditions , ac operation ( not taken into consideration in factory testing) driver habits ( placing auto in neutral while at lights saves fuel)
hard acceleration ' sudden stops, driving over 60mph or 100 km all affect real consumption figures
as for advice , use a quality octane rating-no e-mix fuels - and drive like the tank has a hole in it and you have to conserve every drop

try and rotate the tires if on has a problem the vibration will change to the rear

Hello,

Please clarify for me! Are you saying all the guage lights come on? And are you for sure it is not the brake light coming on?

And have you checked your fluids, oil, brake etc,.

The only reason I ask is that, I have guages light up also, but usually it is either the brake light or the air-bag light and mostly as you stated, when I'm coming to a stop or braking or even driving under 40 mph! Never when I'm on the Interstate.

I have air in my brake lines causing the brake light to come on, which I need bled bad, the air-bag is a fluke, I don't even like them, let alone trust them! I'm still driving though!

I would say, it's okay to drive, no more than you are driving it, but...

If your check engine light comes on & off, most likely you are getting low on some kind of fluid or something needs to be fixed?

When you have a chance go to Advance Auto or Auto Zone and ask them to test your car for a faulty sensor or switch...they do it for FREE! They hook a diagnostic machine up to your car, doesn't take too long a few minutes maybe, it will tell exactly what is wrong.

Kind Regards!

Martie

the fuel filter is located on the side of the driver side frame rail just underneath the car

it is held in by 1 or 2 clamps and looks like this


Good luck!

The shaking may be remedied by having your tires balanced
I have no idea what "Guatemala" means in this context
Sounds like you're asking about a temperature guage that is faulty or a faulty sending temperature sensor

that is one grimlin that is pretty well cornered your ignition switch is command central for all you listed that was not working properly inside the barrel of your ignition are the contact pins that supplies power to everything that requires power that why when you turn ignition off everything shut down so your battery does not die out .i would say that there is a 99% chance that your ignition is shot.

It is typically 10 drive cycles and could take anywhere from 2 to 5 days depending on the type of driving you do. Try to take the car on the highway for a few miles, get off the highway, shut it down for a while, then do some local street driving.

first of all, check voltage at battery car off should read at least 12.5 to 13 volts. now start car. at battery it should read at least 14 volts, if lower then 14 volts check alternator.

Hello. Begin by changing the fuel filter. Also add a bottle of a fuel additive called seafoam to the fuel tank. Then drive it. J.

I think your buick has a pressure coolant system so you may have air in the system and need too bleed it and for the light coming on while on the highway most likely low coolant when your driving the higher rpm the more coolant is drawn into the motor and triggering the light from coolant reservoir running low on coolant