Quick Answer: Silverado and Sierra thermostats share the same GM part numbers because both trucks run identical engines and cooling systems. Most 4.3L, 4.8L, 5.3L, 6.0L, and 6.2L applications open between 186°F and 207°F, and 2007-and-newer trucks typically require a complete integrated housing assembly rather than a standalone valve. Budget roughly $10 to $70 for the part and one to two hours for the job.
What the Thermostat Does in Your Silverado or Sierra
The thermostat is a temperature-sensitive valve that blocks coolant flow to the radiator until your truck’s engine reaches operating temperature. A wax pellet inside the valve expands as coolant heats up, pushes the valve open, and lets hot coolant circulate through the radiator. This single moving part controls how fast your truck warms up, how well your heater works, and how efficiently the engine burns fuel.
Both trucks use the same GM cooling architecture, so a Silverado thermostat and a Sierra thermostat with matching engine displacement and model year are almost always the identical part. The same applies for the Tahoe, Suburban, Yukon, Yukon XL, Avalanche, and Escalade, which is why a 2015 Suburban thermostat and a 2015 Silverado 1500 thermostat cross-reference to the same assembly.
Signs Your Silverado or Sierra Thermostat Has Failed
Thermostats fail in two directions, and each one produces a distinct set of symptoms.
When the Thermostat Sticks Closed
Coolant can’t reach the radiator, so the temperature gauge climbs past 230°F, steam rolls out from under the hood, and the engine risks warped heads or a blown gasket. Shut your truck down immediately if you see this.
When the Thermostat Sticks Open
Coolant circulates constantly, so the engine never reaches operating temperature. You’ll notice a gauge that sits below the halfway mark, a heater that blows lukewarm air, longer warm-up times on cold mornings, and worse fuel economy.
Trouble Codes To Watch For
Your truck’s powertrain control module (PCM) watches for a cold-running engine and stores a code when it detects one. Common codes for these trucks include P0128 (coolant temperature below thermostat regulating temperature), P0125 for insufficient coolant temperature, P0597 for models with heated thermostats, and P01F0 for 6.6L Duramax applications. Our P0128 code guide and our rundown of bad thermostat symptoms walk through the full diagnostic process.
What To Check Before You Replace It
Check your truck’s coolant level, inspect the cooling fan operation, and verify the coolant temperature sensor reading with a scan tool. A low coolant level or a faulty sensor closely mimics faulty thermostat symptoms.
Thermostat Specs by Engine and Generation
| Years | Platform | Engine | Opening Temp | Configuration |
| 1999-2006 | GMT800 | 4.3L V6 | 195°F | Standalone valve, separate housing |
| 1999-2006 | GMT800 | 4.8L, 5.3L, 6.0L | 186°F | Standalone valve or outlet with thermostat |
| 2007-2013 | GMT900 | 4.8L, 5.3L, 6.0L, 6.2L | 187°F-195°F | Often integrated housing |
| 2014-2018 | K2XX | 4.3L, 5.3L, 6.2L | 207°F | Integrated housing assembly |
| 2019-present | T1XX | 2.7L Turbo, 5.3L, 6.2L | Electronically controlled | Integrated assembly or coolant control valve |
| 2001-2021 | HD Duramax | 6.6L | 185°F front, 180°F rear | Two separate thermostats |
GMT800 Trucks: 1999 to 2006
If you searched for a 2000 Chevy Silverado thermostat, you’re looking at a traditional standalone valve. The 4.3L V6 uses a 195°F unit like the Motorad 2065-195, while 4.8L, 5.3L, and 6.0L V8 trucks with the updated GM water pump take a 186°F copper and stainless valve. Some 2000 Sierra 1500 applications ship as a complete aluminum outlet with the thermostat preinstalled.
K2XX Trucks and GM SUVs: 2014 to 2018
If you searched for a 2015 or 2016 Silverado 1500 thermostat, a 2014 Sierra thermostat, or a 2015 or 2016 Suburban thermostat, you’re dealing with the K2XX integrated design calibrated to open at 207°F. GM molded the thermostat, the housing, the gasket, and in many cases the temperature sensor into one sealed plastic unit. The Four Seasons 86006 covers the 2015 Silverado 1500, and the same assembly fits the 2016 Sierra 1500, which shows just how tightly the two platforms overlap.
Why Your Replacement Arrives as a Complete Housing
Owners of 2007-and-newer trucks often ask whether they can install just the thermostat and reuse the original housing. For most of these applications, you can’t. GM stopped selling the valve separately because it presses into a plastic housing that warps and cracks with age, and the sealing surface won’t hold once the housing distorts. Buying the assembly actually works in your favor: you get a fresh gasket, a new sealing surface, and a new coolant temperature sensor for many part numbers, all for less than the cost of chasing a leak twice.
What GMT800 Owners Can Do Instead
GMT800 owners have more flexibility. You can replace the valve alone, though a cracked or corroded housing means you’ll want a new one. Browse Sierra 1500 thermostat housings or jump straight to a 1999 Sierra 1500 housing to check fitment.
How To Replace a Silverado or Sierra Thermostat
Plan on one to two hours for a 1500-series gas truck. HD Duramax models take longer because you’re replacing two thermostats and working around the turbo plumbing.
Step-by-Step Procedure
- Let the engine cool completely, then drain enough coolant to drop the level below the housing.
- Remove the air cleaner duct or engine cover to reach the front of the intake manifold.
- Disconnect the upper radiator hose and unplug the coolant temperature sensor connector.
- Unbolt the housing, usually two or three bolts, and pull the old assembly free.
- Clean the mating surface thoroughly. Any old gasket residue creates a leak path.
- Install the new assembly with the spring side facing the engine block on standalone valves. Torque the bolts to your service manual specification, commonly around 15 lb-ft.
How To Bleed the Cooling System
Refill with the correct coolant, run the engine with the heater on high, and bleed air from the system until the upper hose gets hot and the gauge stabilizes. Skipping this step causes more comebacks than any other mistake, because trapped air creates a false overheat reading and a heater that blows cold.
How Much Does a Silverado or Sierra Thermostat Replacement Cost?
Parts run from about $10 for a basic GMT800 valve to roughly $70 for a K2XX integrated assembly. HD Duramax thermostat pairs land higher because you’re buying two units plus a housing seal. Independent shops typically charge $120 to $250 for labor, and dealers often quote more. Doing the work yourself on a gas 1500 saves most of that.
Can You Find OEM Thermostats for Silverado and Sierra Online?
Yes. ACDelco supplies the factory thermostat for both trucks, and you’ll also find OE-equivalent units from Motorad, Gates, Mahle, Dorman, and Four Seasons. Because the Silverado and Sierra share GM part numbers, a single verified fitment covers both nameplates.
Where To Shop by Year and Engine
CarParts.com lists thermostats by year, make, model, and engine so you don’t guess at a cross-reference. Start with Chevrolet Silverado 1500 thermostats, the full Chevrolet thermostat catalog, 2015 Silverado 2500 HD thermostats, or 2008 GMC Sierra 1500 thermostats. Have your engine displacement and VIN handy, since 1500 trucks offered several engines in the same model year.
Frequently Asked Questions
Most last 100,000 miles or more, though plastic integrated housings often fail sooner. Many owners replace them preventively around the 100,000-mile mark.
A stuck-open thermostat lets you limp home, but a stuck-closed one can destroy your engine within minutes. Pull over and shut it down if the gauge climbs.
In GMT800 trucks, yes. You’ve already drained the coolant, the labor overlaps heavily, and a fresh water pump saves you a second teardown.
GM specifies Dex-Cool, the orange extended-life formula. Don’t mix it with green conventional coolant.
Yes. The 6.6L uses a 185°F front unit and a 180°F rear unit, and you should replace both together.
Often it will, because the PCM expects the engine to reach a target temperature within a set window. Stick with the OE rating unless you’ve tuned for it.
Your truck’s thermostat costs a fraction of what an overheated engine will, so don’t wait for the gauge to spike before you act. CarParts.com stocks Silverado and Sierra thermostats and housings from ACDelco, Motorad, Gates, and Dorman, all backed by guaranteed fitment, free 60-day returns, and a Lifetime Replacement Guarantee. Enter your truck’s year, make, model, and engine into our vehicle selector, and get the right part shipped to your door in just a few days.
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