Engine Coolant Thermostat Guide for the 2010-2016 Chevrolet Camaro
Everything a 5th Gen Camaro owner needs to know about replacing a faulty engine thermostat.
- Identify your engine first; V8 thermostat replacement is easy and cheap, while the V6 is difficult and expensive.
- A P0128 check engine light almost certainly means your thermostat has failed in the open position and needs to be replaced.
- For most owners, a standard OEM-temperature replacement from a brand like Gates or Motorad is the most reliable choice.
- Be cautious with lower-temperature 'performance' thermostats, as they can have reliability issues and may not be suitable for a stock vehicle.
Is Your Camaro Thermostat Failing?
A thermostat is a simple part, but when it fails, it can cause noticeable problems. For the 2010-2016 Camaro, the most common failure is the thermostat sticking in the open position. This is often what triggers the check engine light and the P0128 diagnostic trouble code. Less often, it can stick closed, which is a more serious issue that can lead to rapid overheating.
Key Symptoms of a Bad Thermostat:
- Engine Not Warming Up Properly: If your temperature gauge takes forever to climb or stays low while driving on the highway, your thermostat is likely stuck open.
- Check Engine Light (P0128 Code): This code specifically means the engine coolant temperature is below the normal regulating temperature, directly pointing to a thermostat that is stuck open.
- Poor Heater Performance: If your cabin heater blows lukewarm air instead of hot, it's because the engine isn't getting hot enough to provide sufficient heat to the heater core.
- Engine Overheating: If the temperature gauge shoots into the red, you see steam from the engine, or get an overheat warning, the thermostat may be stuck closed. This is an emergency that requires you to stop the engine immediately to prevent severe damage.
V6 vs. V8 Engine: A Critical Difference
Before ordering a part or getting a repair quote, you MUST know which engine you have. The replacement procedure is drastically different.
- V8 (6.2L LS3, L99): The thermostat is located on the front of the engine at the top, connected to the upper radiator hose. It is easily accessible and simple to replace, typically taking less than an hour.
- V6 (3.6L LLT, LFX): The thermostat is located at the rear of the engine, buried under the intake manifold. This is a much more difficult and labor-intensive job, requiring several hours and the removal of the throttle body and intake manifold.
Choosing the Right Aftermarket Thermostat
For most owners, a standard, OEM-temperature replacement is the best choice. Performance thermostats that open at a lower temperature are available, but they have trade-offs.
Brand Tiers
- OEM-Equivalent Replacements (Recommended for most drivers): Brands like Gates and Motorad are well-known suppliers that produce reliable, direct-fit thermostats. They are designed to work just like the original part that came in your Camaro and are a safe bet for a daily driver. Calorstat is another major OEM supplier offering similar quality.
- Performance (Lower Temperature): Brands like Mishimoto and PRW offer thermostats that open at a lower temperature (e.g., 160°F or 169°F). These are intended for heavily modified or track-focused cars to increase the cooling system's efficiency. However, using one on a stock or lightly modified car can prevent the engine from reaching its optimal operating temperature, potentially affecting performance and fuel economy.
A Note on Mishimoto: While popular in the performance scene, there are numerous owner reports on forums about Mishimoto thermostats for this Camaro generation failing prematurely. The issue often involves the rubber seal degrading or coming loose, causing the thermostat to get stuck open—the very problem you were trying to fix.
How Much Does a New Thermostat Cost?
The cost depends heavily on your engine type (due to labor) and the brand you choose.
| Part / Service | Estimated Cost |
|---|---|
| New Aftermarket Thermostat Part | $20 - $97 |
| Shop Labor (V8 Models) | $80 - $150 |
| Shop Labor (V6 Models) | $250 - $450+ |
| Total Professional Replacement (V8) | $100 - $250 |
| Total Professional Replacement (V6) | $270 - $550+ |
Cost estimates are approximate and can vary by location and shop.
Pro Tip: Coolant Flush
Replacing the thermostat requires draining at least some of the coolant. This is the perfect time to perform a full coolant flush, especially if your vehicle is approaching 100,000 miles or the coolant has never been changed. Always use a DEX-COOL compatible coolant.
Frequently Asked Questions
My mechanic quoted 3+ hours for a thermostat, is that a rip-off?
If you have a V6 engine, no. The thermostat is located at the back of the engine under the intake manifold, and the job is very labor-intensive. If you have a V8, the job should only take about an hour, and a 3+ hour quote would be excessive.
What exactly does the P0128 code mean?
P0128 means "Coolant Temperature Below Thermostat Regulating Temperature." Your car's computer expects the engine to warm up to a specific temperature within a certain time. When the thermostat is stuck open, the engine runs too cool for too long, triggering this specific code. It is one of the most definitive codes pointing to a failed thermostat.
Should I install a lower temperature 'racing' thermostat?
For most daily-driven Camaros, the answer is no. The stock engine is designed to run efficiently at the factory temperature (around 187-195°F). A lower temp thermostat can cause the engine to run too rich, decrease fuel economy, and may even trigger a P0128 code if the temperature is too low. They are best reserved for highly modified engines with custom tuning to match.
How can I tell if my thermostat is stuck open or stuck closed?
Stuck Open: The engine warms up very slowly or not at all. The temperature gauge stays low, and the heater blows cool air. You will likely get a P0128 check engine light. Stuck Closed: The engine overheats very quickly. The temperature gauge will spike into the red, and you may see steam from under the hood. This is a much more dangerous situation.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12620254 12632102 12653316
Stock opening temperature is approximately 187°F (86°C). Varies by engine (V6 vs V8) and specific year. Aftermarket performance options are available at 160°F and 169°F.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Chevrolet Camaro: