Brands Vehicles
Lowest Prices
Free Returns
Online Since 2009
JOIN GEARS TO SAVE 5%
Shop All Brands Shop All Vehicles

  2. Auto Parts
  3. Belts and Cooling
  4. Thermostat and Housing
  5. Engine Coolant Thermostat
  6. ACDelco 12T121D for 2004

ACDelco 12T121D Engine Coolant Thermostat
for 2004 (please select make/model)

ACDelco 12T121D Engine Coolant Thermostat - 2004

ACDelco
Brand:ACDelco
Part Number: 12T121D
UPC: 00707773320105
Weight: 0.17 lbs
Condition:New



Availability:
0 in Stock
 OUT OF STOCK

Product Information

Description:

Get the ACDelco 12T121D Engine Coolant Thermostat for your 2004. Buy now and secure your purchase online!

ACDelco Professional Engine Coolant Thermostats control the flow of coolant through your vehicle's radiator to help the engine reach and maintain its optimal operating temperature, and are a high quality replacement for many vehicles on the road today. These engine coolant thermostats are manufactured to meet your expectations for fit, form, and function. WARNING: Cancer and Reproductive Harm - https://www.P65Warnings.ca.gov

Features and Benefits:

  • Controls the flow of coolant through the radiator to help your vehicle's engine reach and maintain its optimal operating temperature
  • Manufactured to meet expectations for fit, form, and function
  • Professional, premium aftermarket replacement
  • Provides the performance and dependability you expect from ACDelco
  • – Have cooling system inspected immediately if instrument panel-mounted temperature gauge indicates engine overheating

Specifications:

Height:
3.2 in.
Length:
3.5 in.
Programming Required:
NO
Seal Type:
Gasket
Weight:
.17 lb
Width:
3.2 in.

Manufacturer Warranty:

24 Month / Unlimited Mile Limited Warranty (Parts Only). Please see ACDelco.com for more details.

Select a vehicle to narrow ACDelco 12T121D Engine Coolant Thermostat fitment info!

Last Updated: 07/22/2021

Years Vehicle Per Vehicle Fit NotesFitment Notes

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Buick Rainier

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Buick Rainier



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
Cadillac CTS

5.7L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Cadillac CTS



5.7L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Cadillac Escalade

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Cadillac Escalade



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
Cadillac Escalade

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Cadillac Escalade



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Cadillac Escalade ESV

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Cadillac Escalade ESV



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Cadillac Escalade EXT

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Cadillac Escalade EXT



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Avalanche 1500

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Avalanche 1500



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2004

 

2004

 
Chevrolet Corvette

5.7L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Corvette



5.7L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Express 1500

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard
 

Chevrolet Express 1500



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Express 2500

4.8L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Express 2500



4.8L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
Chevrolet Express 2500

5.3L V8 Gas OHV,
6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Express 2500



5.3L V8 Gas OHV,
6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Express 3500

4.8L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Express 3500



4.8L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
Chevrolet Express 3500

6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Express 3500



6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Silverado 1500

4.8L V8 Gas OHV,
5.3L V8 Electric/Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Silverado 1500



4.8L V8 Gas OHV,
5.3L V8 Electric/Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2004

 

2004

 
Chevrolet Silverado 2500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Silverado 2500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Silverado 2500 HD

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Silverado 2500 HD



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
Chevrolet Silverado 2500 HD

6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Silverado 2500 HD



6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Silverado 3500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Silverado 3500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
Chevrolet Silverado 3500

6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Silverado 3500



6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2004

 

2004

 
Chevrolet SSR

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet SSR



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Suburban 1500

5.3L V8 Flex OHV,
5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Suburban 1500



5.3L V8 Flex OHV,
5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Suburban 2500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Suburban 2500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Chevrolet Tahoe

4.8L V8 Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Tahoe



4.8L V8 Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2003

 

2006

 

2005

 

2004

 

2003

 
Chevrolet Trailblazer EXT

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Chevrolet Trailblazer EXT



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Envoy XL

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Envoy XL



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
GMC Envoy XUV

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Envoy XUV



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Savana 1500

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Savana 1500



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Savana 2500

4.8L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Savana 2500



4.8L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
GMC Savana 2500

5.3L V8 Gas OHV,
6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Savana 2500



5.3L V8 Gas OHV,
6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Savana 3500

4.8L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Savana 3500



4.8L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
GMC Savana 3500

6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Savana 3500



6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Sierra 1500

4.8L V8 Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Sierra 1500



4.8L V8 Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2004

 

2004

 
GMC Sierra 2500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Sierra 2500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Sierra 2500 HD

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Sierra 2500 HD



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
GMC Sierra 2500 HD

6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Sierra 2500 HD



6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Sierra 3500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Sierra 3500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2005

 

2004

 

2005

 

2004

 
GMC Sierra 3500

6.0L V8 CNG OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Sierra 3500



6.0L V8 CNG OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Yukon

4.8L V8 Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Yukon



4.8L V8 Gas OHV,
5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Yukon XL 1500

5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Yukon XL 1500



5.3L V8 Flex OHV,
5.3L V8 Gas OHV,
6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
GMC Yukon XL 2500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

GMC Yukon XL 2500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Hummer H2

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Hummer H2



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2006

 

2005

 

2004

 
Isuzu Ascender

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Isuzu Ascender



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2003

 

2006

 

2005

 

2004

 

2003

 
Isuzu NPR

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard
 

Isuzu NPR



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard

1 Per Vehicle

2006

 

2005

 

2004

 

2003

 

2006

 

2005

 

2004

 

2003

 
Isuzu NPR-HD

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard
 

Isuzu NPR-HD



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard

1 Per Vehicle

2004

 

2004

 
Pontiac GTO

5.7L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Pontiac GTO



5.7L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2004

 

2004

 
Workhorse Custom Chassis P42

4.8L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard
 

Workhorse Custom Chassis P42



4.8L V8 Gas OHV Professional
Temperature 187F
Includes seal
OEM Recommended Temp
Standard

1 Per Vehicle

Didn't find a match for your vehicle?

   See Other Choices



Customers who bought ACDelco 12T121D Engine Coolant Thermostat also purchased

ACDelco 89060413 Engine Intake Manifold Gasket Set
ACDelco 89060413 Engine Intake Manifold Gasket Set
ACDelco PF46F Engine Oil Filter
ACDelco PF46F Engine Oil Filter
ACDelco 291-315 Axle Shaft Seal
ACDelco 291-315 Axle Shaft Seal
ACDelco 24208576 Auto Trans Filter Kit
ACDelco 24208576 Auto Trans Filter Kit
ACDelco A3181C Air Filter
ACDelco A3181C Air Filter
ACDelco 19313320 PCV Valve
ACDelco 19313320 PCV Valve