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Gas Guage

I have a 1996 Oldsmobile Aurora and have recently had the fuel pump relplaced. Since the change, the gas guage fluctuates but mostly it will read correctly for about 1/2 hour then go to a full indicaion even though the gas level is actually down. My mechanic has tried to imporve the ground on the pump assembly, but it has not made any differce. Is there something he is missing?

How long ago is ‘recently’?

I had the fuel sending unit changed in the tank of my 2000 Olds Silhouette a year ago because the gauge was fluctuating too. $340+ (Cdn) Never again. The tank has to be dropped.

About a month later it started all over again.

I got a bottle of fluid (I forget the name) from a GM dealer and dumped it in the tank and used the odometer and overhead computer to track the miles.

What this stuff is supposed to do is clean the sending unit to keep it working.

After two bottles of this stuff and three tanks of gas the guage finally started working again. This ‘cleaner’ is NOT cheap at $25 each.

Needless to say, I don’t use that stuff any more.

I still don’t trust it and have continued using my other methods of keeping track of the miles.

any other ideas of what the name of this 'fluid is"

that sounds like i may need some.

I can’t for the life of me remember the name but a quick phone call to a GM dealer parts dept. would be the easiest way.

thanks, rr, my wife’s alero hs sm prob. i’l give it a try.

Let us know what they call it will you? I’d appreciate it.

When I went to get this stuff the first time, the parts guy said GM recommended one bottle (not big either) at each third fuel up to keep the fuel pump and sending unit clean.

One such additive that has worked to clean the contacts for the sender unit is called Techron, made by Chevron. It may take a couple of bottles to do the job in some cases, but have heard it works. A 12oz. bottle sells for between 7 to 9 dollars. Another product called Seafoam may work also.

I have a similar problem with my 2001 Silverado. After reading this post, I put some Sea Foam in my gas tank last night and will wait to see what happens. In the meantime, during a slow time at work this morning, I found some additional information on the issue, including the specifics on the GM cleaner for this problem. Whoever wrote this seems to know what s/he is talking about. I will paste it here:

Re: 2002 Silverado Electrical Bug

This info was posted by another user on a different forum. It may be worth a shot too.

GM has issued a new / revised fuel system cleaner that may correct your erratic fuel gauge operation. I have used this cleaner in my Corvette and it cured the erratic gauge operation. (NOTE: The new cleaner contains the word, “PLUS”. Do not purchase the older style from your dealer which still may be stocked. The part number for the older version and new version is the same.)

Information about the new cleaner:

GM Fuel System Treatment PLUS, Fuel Sending Unit Corrosion and Fuel System Deposits
2006 and Prior All GM Cars and Trucks

GM Fuel System Treatment PLUS, P/N 88861011 (for U.S. ACDelco?, use 88861013) (in Canada, 88861012), is now available.

Added Benefits and Uses
The PLUS portion of GM Fuel System Treatment PLUS is the addition of a filmer additive that, when used regularly, can protect fuel system sending units from the corrosive effects of certain sulfur contaminants found in some of today’s gasoline.

Sulfur contamination can disrupt electrical continuity of certain fuel sending units and lead to erratic or false fuel gauge readings. With scheduled usage, GM Fuel System Treatment PLUS protects against the effects of harmful sulfurs in gasoline.

You Get Four Benefits
One bottle of GM Fuel System Treatment PLUS added to the fuel tank at each oil change:

? Cleans – Sulfur corrosion from fuel gauge sending units.

? Prevents – Harmful sulfur components from attacking sensitive fuel system electronics.

? Protects – By coating metallic surfaces of the fuel system.

? Removes – Engine deposits left from use of poor quality fuels.

GM Fuel System Treatment PLUS will replace the original GM Fuel System Treatment, P/N 12345104 (in Canada, 89020804). The original formula may still be available for a limited time, and provides the excellent Fuel System Cleaning aspects of the new product without the filmer.

NOTE: The interval for using this cleaner is NOW 3000 miles, NOT 1500.

Very informative post. The gas gauge on my 2000 Blazer has been on the fritz since 2/07. I tried Chevron Techron with little or no improvement. I might pick up a bottle of the GM cleaner at the dealer and try that next.

I picked up a 20 oz bottle of GM Fuel System Treatment PLUS this morning, $26.91 with tax. Even the guy at the parts counter remarked about the price. It’s in the same bottle that Chevron Techron comes in, hopefully there’s more to it than the Techron. I’ll post back if there’s any improvement in the gauge.


Ed B.

Just a follow up to my last post. After running Chevron Techron Plus and GM Fuel System Treatment PLUS to two tanks of gas there was no improvement to the gas gauge, however the Blazer is running very smooth so it wasn’t a total waste. I’m pretty sure that the GM product is just rebadged Chevron Techron, so in the future I’ll stick with Techron. I’ll wait a few weeks and try a can of Seafoam next.

Ed B.

Since the problem with the gauge didn’t change using the cleaner I’m sure you realize that this trouble may be beyond what just a cleaner can do to fix it.