2000 DTS ERRATIC FUEL GAUGE

[GJ2000DTS]

At about 50% full, the fuel gauge acts erratic and moves to full and then back to less than 50%. As acutal fuel level moves towards empty, full gauge will move towards full. When I go through the information sequence, the 'Gallons of Gas Used' reads accurately moving towards 18.5 Gallons but again, the fuel gauge will swing to show a 'Full Tank.'

Also, around town I'm getting 12-13 MPG; on the Highway about 18-19; premium fuel, 3000 mile oil changes.

Feb (06) The Dealer, under GM warranty, replaced the engine at about 90.0K mile due to a cracked engine block; car actually runs great now and no longer burns oil as had been doing. But I'd like to get better gas mileage.

Thanks

[stsjoe]

Fuel gauge problem is most likely the sending unit and you have to replace the pump in the gas tank to fix it. On a 2000 you may not have to drop the tank, others who know more will chime in. The mileage seems low, check the tire pressure, air filter and I'll bet money they used the old plugs and wires if so new ones would help

[JimD]

Your fuel gauge problem has probably set one or more trouble codes. To display the codes read here

http://www.caddyinfo.com/readingcodes.html

Your fuel economy is not related to the fuel gauge problem.

[Bruce Nunnally]

Fuel gauge problem is most likely the sending unit and you have to replace the pump in the gas tank to fix it. On a 2000 you may not have to drop the tank, others who know more will chime in. The mileage seems low, check the tire pressure, air filter and I'll bet money they used the old plugs and wires if so new ones would help

I agree with STSJOE. The fuel senders do fail and this is not an unlikely symptom.

[kens96]

You can buy some bottles of Techtron and run them through the gas tank with top tier gas like Shell as the directions state and see if the symptoms clear up before replacing the sending unit. I had a similar problem with my 98 Vette and it cleared up with two tanks worth. Have stayed with Shell and the problem has not returned.

[KHE]

There is an access panel in the trunk that permits the fuel sender replacement without dropping the tank.

[BodybyFisher]

You can buy some bottles of Techtron and run them through the gas tank with top tier gas like Shell as the directions state and see if the symptoms clear up before replacing the sending unit. I had a similar problem with my 98 Vette and it cleared up with two tanks worth. Have stayed with Shell and the problem has not returned.

Ken, my gage is crazy also, I didnt know that the Techron could correct it. I will try some, thanks

By the way, I will mail the starter solenoid shortly, I have been crazed at work

[kens96]

There is a lot of info on the Corvette Forum about this topic. Seems to have something to do with the sulfur content of the gas. It is hit or miss on whether the sending unit is too far gone to clean the sulfur off it, but is is better than dropping the tank if it works. I was lucky and the car is 9 years old.

[JohnnyG]

my gage is crazy also, I didnt know that the Techron could correct it. I will try some, thanks

Body, You get some crazy gas out there in the NY Harbor! A lot of it is above the corrosivity limits of the fuel level sensor, and is probably the ultimate source of your problem. I'd truly like to know if fuel additives alone will solve your problems. In my company, we don't sell gas with high corrosivity, nor try to fix it by putting in additional additives. It is either sold off for recycling, or blended down to within specifications before being offered for sale.

Let me know if this works!

On a side note:

BP has recently requested that their additive levels be boosted at my facility, up to about 1/2 gallon of additive/ 1000 gallons in their premium grades. It hasn't happened yet, they were just asking about equipment capabilities. This would put their additive levels above that of Chevron, just for future reference.

[krissyd]

Hello Everyone,

I *just* bought a 2000 Cadillac Deville with about 83,000 miles on it. I have never owned a Cadillac before and don't really know much about cars.

I drove the car for the second day today and noticed that the fuel gauge changed dramatically during my 20 minute trip. It started looking like it was below 1/2 a tank, as it had seemed before, then at some point it showed over 1/2 a tank, then down again then up to almost full and down again.

What the heck? is this the same issue mentioned here? The car did not come with a users manual and I just got one on Ebay, but haven't received it yet. I can't imagine that what I am looking at is not the fuel gauge, however.

Another issue that I will bring up, if you don't mind (you all are so knowledgeable) is that when the car was warmed up to the middle of the gauge it still had steam or smoke coming out of the tail pipes. It was a cold morning, but not many other cars had smoke coming out. How concerned should I be?

Thanks so much!

Krissy

Fuel gauge problem is most likely the sending unit and you have to replace the pump in the gas tank to fix it. On a 2000 you may not have to drop the tank, others who know more will chime in. The mileage seems low, check the tire pressure, air filter and I'll bet money they used the old plugs and wires if so new ones would help

I agree with STSJOE. The fuel senders do fail and this is not an unlikely symptom.

[krissyd]

Hello Everyone,

I *just* bought a 2000 Cadillac Deville with about 83,000 miles on it. I have never owned a Cadillac before and don't really know much about cars.

I drove the car for the second day today and noticed that the fuel gauge changed dramatically during my 20 minute trip. It started looking like it was below 1/2 a tank, as it had seemed before, then at some point it showed over 1/2 a tank, then down again then up to almost full and down again.

What the heck? is this the same issue mentioned here? The car did not come with a users manual and I just got one on Ebay, but haven't received it yet. I can't imagine that what I am looking at is not the fuel gauge, however.

Another issue that I will bring up, if you don't mind (you all are so knowledgeable) is that when the car was warmed up to the middle of the gauge it still had steam or smoke coming out of the tail pipes. It was a cold morning, but not many other cars had smoke coming out. How concerned should I be?

Thanks so much!

Krissy

Fuel gauge problem is most likely the sending unit and you have to replace the pump in the gas tank to fix it. On a 2000 you may not have to drop the tank, others who know more will chime in. The mileage seems low, check the tire pressure, air filter and I'll bet money they used the old plugs and wires if so new ones would help

I agree with STSJOE. The fuel senders do fail and this is not an unlikely symptom.

[rek]

"You can buy some bottles of Techtron and run them through the gas tank with top tier gas like Shell as the directions state and see if the symptoms clear up before replacing the sending unit. "

[BodybyFisher]

my gage is crazy also, I didnt know that the Techron could correct it. I will try some, thanks

Body, You get some crazy gas out there in the NY Harbor! A lot of it is above the corrosivity limits of the fuel level sensor, and is probably the ultimate source of your problem. I'd truly like to know if fuel additives alone will solve your problems. In my company, we don't sell gas with high corrosivity, nor try to fix it by putting in additional additives. It is either sold off for recycling, or blended down to within specifications before being offered for sale.

Let me know if this works!

On a side note:

BP has recently requested that their additive levels be boosted at my facility, up to about 1/2 gallon of additive/ 1000 gallons in their premium grades. It hasn't happened yet, they were just asking about equipment capabilities. This would put their additive levels above that of Chevron, just for future reference.

You know Johnny, a couple of bottles of Techron over a couple of weeks did appear to clear up my problem, its definately not as bad as it was.

On another thread we discussed that high sulfer fuels was plating the fuel level sensor and causing this problem

I would recommend a couple of bottles of Techron or to start using a fuel that has Techron in it like Chevron. Follow the directions on the Techron bottle.

[Texas Jim]

Hello Everyone,

I *just* bought a 2000 Cadillac Deville with about 83,000 miles on it. I have never owned a Cadillac before and don't really know much about cars.

Another issue that I will bring up, if you don't mind (you all are so knowledgeable) is that when the car was warmed up to the middle of the gauge it still had steam or smoke coming out of the tail pipes. It was a cold morning, but not many other cars had smoke coming out. How concerned should I be?

Thanks so much!

Krissy

Krissy,

It is PROBABLY nothing to worry about.

It COULD be an indication of serious problems..but probably it is normal.

Condensation in the exhaust system will cause the steam from the tailpipes.

Check your coolant level and make sure it is at the correct level.

[KHE]

If the car is not overheating, don't worry about it. In cold weather, you will always see steam/water vapor coming out of the exhaust.