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2003 Impala Gas Gauge

I’d have replaced the sender, too, if the truck (SUV really) had an access panel to get to the pump without dropping the 31.5 gallon tank. Well, it HAS one now thanks to the Avalanche owners forum showing me where to cut. Drill-Cut-snip in the right spot and voila, pump comes out from under the rear seat. Made a coverplate and now future repairs are easy.

I believe it is a stepper motor, in my gm I got a package for $22 to replace all the stepper motors in the cluster. Speedometer would show 85 mph when going 55, eventually the guage will die, so if you can solder in some stepper motors for $22 vs replacing the cluster for$500 ($300 for the cluster and $200 to program) do it, or there are places that do it for a reasonable cost, $60 to $100. Ended up with bad tach, bad spedometer and bad oil pressure guage when I did min. All is good now.

@Triedaq

"@common_sense_answer. This is interesting. My problem on the Uplander started after I started buying my gas at a different station."

It is, for sure. This was an expensive repair at one time. When GM started doing them under warranty then an inexpensive kit became available for the newer vehicles that were still covered. Fortunately, I could buy that kit (all the dealers stocked them) for my old car and use the necessary part of it for my old car (the “wiper” was an exact fit part, although I noticed the wiring was different on the whole sensor). One only needed to purchase the kit used for warranty fuel gauge repairs on newer GM SUVs/Trucks and know what to do with them. I taught myself with You Tube.

I wonder if it has anything to do with GM being one of the companies specifying Top Tier Gasoline in their Owner’s Manuals?
CSA

When I got in today the gauge was where given the miles I have driven since fill up should be but as I drove to work if I braked it would move, when I excellarated it moved, When I was at a stop light it would return to where it should be…Maybe I have a ghost in my tank…

[quote=“bertrand, post:24, topic:95678, full:true”]
When I got in today the gauge was where given the miles I have driven since fill up should be but as I drove to work if I braked it would move, when I excellarated it moved, When I was at a stop light it would return to where it should be…Maybe I have a ghost in my tank…
[/quote]Sounds like a baffle in the tank may have broken loose.

What is a baffle and what does it do and could it do damage to my engine or car?

General Motors fuel tanks have baffles inside?

[quote=“Nevada_545, post:27, topic:95678, full:true”]
General Motors fuel tanks have baffles inside?
[/quote]No idea. Baffling for preventing of such gauge flucuation is probably handled by the design of the sending unit.

[quote=“bertrand, post:26, topic:95678, full:true”]
What is a baffle and what does it do and could it do damage to my engine or car?
[/quote]A baffle in this context is a piece of sheet metal that reduces the sloshing around of a liquid. I don’t know if your tank even has any baffling.

I had a 1975 AMC Pacer and it had a baffle in the gas tank. The baffle did break loose and it would shift in the tank and affect the fuel gauge. However, the loose baffle could be heard in the cabin, particularly when one went around a corner. It made a clanging noise as it hit the side of the tank.

Any particular reason why OP’s fuel tank should NOT a baffle . . . ?

It’s not a luxury car feature, or even a high-tech feature

I have replaced hundreds of fuel pumps and level units and a couple of dozen fuel tanks, no baffles in anything that I have worked on. Have you seen baffles in these GM tanks?

I don’t know for certain, but I’d be surprised if the tank doesn’t have a baffle. A baffle (along with electrical dampening) helps keep the fuel level around the pump’s pickup reasonably stable for an uninterrupted supply and acceptably stable gage reading and it prevents a tank low of gas from sucking air under high-lateral G situations. Most cars cannot approach 1G, but even 1/4G would be enough to move the gas up against the wall. Baffles also prevent load transfer, and while I don’t know if in a car this is a handling stability factor, I’d guess that it is.

Not in GM vehicles . . . but in other vehicles

I still fail to see your point

Just because you haven’t seen a baffle in a GM tank doesn’t imply anything, IMO

Do you want the OP to believe he needs a new fuel tank based on the baffle theory?

You are missing MY point

I’m simply stating that your assertion that you’ve seen no baffles on GM vehicles so far is not terribly interesting for me

I never said OP’s fuel tank had a baffle

In fact, I didn’t even imply it

You’re reading too much into this, as far as I’m concerned

I could care less about the “baffle theory” . . . it wasn’t my theory,

In fact, I don’t particularly WANT OP to do anything, as far as the fuel tank is concerned

I’m talking to you, not OP

And my previous comment was specifically directed at you, as you can see by the arrows in the upper right

Frankly, I’m, er, baffled that my comment led to such a heated discussion. :astonished:

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You shouldn’t be

You KNOW that us regulars really get into it :smirk_cat:

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hmm … interesting discussion. Am I under a misapprehension? I thought until now nearly all gas tanks in modern cars use baffles? Otherwise the driver would be constantly be hearing the fuel slop around as they turned corners or came to a stop, wouldn’t that be pretty annoying?

I may be wrong, but I think a baffle may be more common in a stamped steel tank

But you’re right in one sense . . . baffles are in common use

Whether or not OP’s car has one or not . . . they are not a feature reserved for high-tech, modern, and/or luxury vehicles