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

ACDelco 12T121D Engine Coolant Thermostat

ACDelco 12T121D Engine Coolant Thermostat

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 vehicle. 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
Showing 100 fitments from page 2 of 2

2003

 

2002

 

2001

 

2003

 

2002

 

2001

 
GMC Sierra 2500 HD

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Sierra 2500 HD



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

2002

 

2002

 
GMC Sierra 2500 HD

6.0L V8 Bi-Fuel OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Sierra 2500 HD



6.0L V8 Bi-Fuel OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. 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

2003

 

2002

 

2001

 

2003

 

2002

 

2001

 
GMC Sierra 3500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Sierra 3500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

1998

 

1997

 

1998

 

1997

 
GMC T6500

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

GMC T6500



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

1 Per Vehicle

1998

 

1997

 

1998

 

1997

 
GMC T7500

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

GMC T7500



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

1 Per Vehicle

2010

 

2010

 
GMC W4500 Forward

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

GMC W4500 Forward



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
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

2003

 

2002

 

2003

 

2002

 
GMC Yukon

5.3L V8 Flex OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon



5.3L V8 Flex OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

2003

 

2002

 

2001

 

2003

 

2002

 

2001

 
GMC Yukon

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

2003

 

2002

 

2001

 

2000

 

2003

 

2002

 

2001

 

2000

 
GMC Yukon

4.8L V8 Gas OHV,
5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon



4.8L V8 Gas OHV,
5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. 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

2003

 

2002

 

2003

 

2002

 
GMC Yukon XL 1500

5.3L V8 Flex OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon XL 1500



5.3L V8 Flex OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

2003

 

2002

 

2001

 

2003

 

2002

 

2001

 
GMC Yukon XL 1500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon XL 1500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

2003

 

2002

 

2001

 

2000

 

2003

 

2002

 

2001

 

2000

 
GMC Yukon XL 1500

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon XL 1500



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. 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

2003

 

2002

 

2001

 

2000

 

2003

 

2002

 

2001

 

2000

 
GMC Yukon XL 2500

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

GMC Yukon XL 2500



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. 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

2003

 

2003

 
Hummer H2

6.0L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

Hummer H2



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. 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

2003

 

2003

 
Isuzu Ascender

5.3L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

Isuzu Ascender



5.3L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. 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

2002

 

2001

 

2000

 

1999

 

1998

 

2002

 

2001

 

2000

 

1999

 

1998

 
Pontiac Firebird

5.7L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard
 

Pontiac Firebird



5.7L V8 Gas OHV Professional
Temperature 187F
Includes seal
w/ Replacement late model water pump requiring seperate thermostat and housing. Thermostat only.
OEM Recommended Temp
Standard

1 Per Vehicle

2009

 

2009

 
Pontiac G8

6.2L V8 Gas OHV
1
 
Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard
 

Pontiac G8



6.2L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
OEM Recommended Temp
Standard

1 Per Vehicle

2009

 

2008

 

2009

 

2008

 
Pontiac G8

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

Pontiac G8



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

1 Per Vehicle

2008

 

2007

 

2006

 

2005

 

2008

 

2007

 

2006

 

2005

 
Pontiac Grand Prix

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

Pontiac Grand Prix



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

1 Per Vehicle

2006

 

2005

 

2006

 

2005

 
Pontiac GTO

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

Pontiac GTO



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
Thermostat only
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

2008

 

2007

 

2006

 

2005

 

2008

 

2007

 

2006

 

2005

 
Saab 9-7x

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

Saab 9-7x



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

1 Per Vehicle

2011

 

2010

 

2011

 

2010

 
Workhorse W62

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

Workhorse W62



6.0L V8 Gas OHV Professional
Temperature 187F
Includes seal
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

2012

 

2011

 

2012

 

2011

 
Workhorse Custom Chassis W62

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

Workhorse Custom Chassis W62



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

1 Per Vehicle


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