Have 2 gremlins in my parents 2000 SSEI.

The fuel tank guage does not work that well...is this a common problem? Do we need to drop the tank?

The driver side air is not cold. I'm assuming its some control with the climate control. Is this a common problem? What should we change?

Can you describe what the fuel gauge is doing or not doing? It'* possible that the sender could be going. It seems to be a fairly common problem for GM, but we haven't seen many in the 2000+ yet. There is an access panel in the trunk that allows you to get to the fuel pump.

As for the air, there are 2 possiblities to start. Low freon, or the air-mix actuator.

the fuel guage is just very erratic. it moves quite a bit. it will show a full tank when the tank is almost empty, etc.

Sounds like the fuel sending unit is going bad. On occasion, some have had theirs straighten around on its own after a time. GM blames it on the sulfur content in some gasolines.

You can replace the fuel sending unit or you can try the additive they have listed in this TSB first to see if it helps.

Fuel System - Fuel System Treatment PLUS(R)

Bulletin No.: 05-00-89-078

Date: November 09, 2005

INFORMATION
Subject:
GM Fuel System Treatment PLUS, Fuel Sending Unit Corrosion and Fuel System Deposits

Models:
2006 and Prior All GM Cars and Trucks
2003-2006 HUMMER H2
2006 HUMMER H3
2006 and Prior Saturn (Canada Only)
2005-2006 Saab 9-7X

GM Fuel System Treatment PLUS

GM Fuel System Treatment PLUS, P/N 88861011 (for U.*. ACDelco(R), 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'* 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.

This is good info to keep in the bank. Maybe this should be on a sticky or in Techinfo for reference.