How Much It Costs to Replace a Thermostat in a 2018 Hyundai Elantra

Replacing the thermostat in a 2018 Hyundai Elantra typically costs between $220 and $400 at a repair shop in the United States, including parts and labor. The thermostat part itself is relatively inexpensive—often $35 to $90—while labor usually runs $150 to $300 depending on shop rates and regional pricing. Costs can be lower if you do the work yourself, but that assumes you have the tools and experience to safely handle coolant and engine components.

What the Thermostat Does and Why It Matters

The thermostat is a small but crucial component in the Elantra’s cooling system, regulating coolant flow to keep the engine at its optimal operating temperature. When it fails—by sticking open or closed—it can cause the engine to run too cold, overheat, trigger warning lights, or affect fuel economy and performance. In a 2018 Hyundai Elantra, a faulty thermostat is often associated with a check engine light, fluctuating temperature gauge, or visible overheating.

Typical Cost Breakdown

The total cost to replace a thermostat in a 2018 Hyundai Elantra comes from two main contributors: the price of the part itself and the labor required to access, remove, and replace it, plus coolant handling. Understanding these components will help you evaluate quotes from repair shops and decide whether professional service or DIY makes more sense.

Parts Cost

The thermostat for a 2018 Hyundai Elantra is usually sold either as a standalone valve or as part of a thermostat housing assembly. OEM (Hyundai-branded) parts are generally more expensive but closely match factory specifications, while aftermarket parts can offer savings with varying levels of quality and warranty coverage.

• Thermostat only: About $35–$65 for quality aftermarket or OEM-equivalent parts.
• Thermostat with housing assembly: Roughly $60–$120, depending on brand and supplier.
• Coolant (if needed): An additional $20–$40 for the correct type of coolant to top off or partially replace what’s drained.
• Gaskets/seals: Often included with the thermostat or housing; if not, expect $5–$15.

Altogether, most owners will see a total parts bill in the $60–$150 range if everything is purchased new from a typical auto parts retailer or dealership, with OEM at the higher end and aftermarket at the lower end.

Labor Cost

Labor costs vary widely depending on where you live and whether you use a dealership or an independent shop. The 2018 Elantra’s thermostat is not the most difficult component to access, but it still requires draining or partially draining coolant and careful reassembly and bleeding of the system.

• Labor time estimate: Typically 1.0–2.0 hours of book time, depending on engine configuration and shop procedures.
• Independent shop rate: Commonly $100–$150 per hour in many U.S. markets.
• Dealership rate: Often $140–$200+ per hour, but with genuine Hyundai parts and factory procedures.
• Typical labor total: Around $150–$300 for most customers, with lower-cost regions on the bottom of that range and high-cost urban areas on the top.

When combined with parts, this places the average professional thermostat replacement bill at roughly $220–$400, though premium dealerships in high-cost cities could occasionally quote slightly more.

Dealership vs. Independent Shop vs. DIY

Where you choose to have the thermostat replaced can significantly influence the final price. Each option offers its own balance of cost, convenience, and perceived reliability, and understanding these trade-offs helps you make a more informed choice.

Hyundai Dealership Pricing

Dealership service centers usually charge the highest labor rates but offer brand familiarity, factory-approved parts, and documented repair histories. For a 2018 Elantra, this can be particularly reassuring if you’re concerned about maintaining resale value or ensuring that all cooling system components meet Hyundai specifications.

• Typical total cost at a dealer: About $280–$450, depending on region and whether additional coolant service or diagnostics are required.
• Benefits: Use of genuine Hyundai parts, technicians trained on Hyundai systems, and better documentation for warranty or resale.
• Potential add-ons: Some dealers may recommend a full coolant flush or additional inspection services, which can raise the bill.

For owners who prioritize warranty compliance, factory parts, and a single point of contact, the dealer premium may be acceptable despite higher hourly labor rates.

Independent Repair Shop Pricing

Independent shops generally charge less per hour than dealerships while still delivering professional-quality work. For a job like a thermostat replacement on a mainstream model like the Elantra, many independents have ample experience and access to quality parts.

• Typical total cost at an independent shop: About $220–$350, often lower if less coolant is needed or parts are sourced competitively.
• Parts flexibility: Ability to use OEM, OEM-equivalent, or budget aftermarket parts based on customer preference and budget.
• Warranty: Most reputable independents offer 12-month/12,000-mile or better warranties on parts and labor.

For many Elantra owners, a trusted independent shop offers the best balance of cost and reliability, especially when the vehicle is out of factory warranty.

DIY Replacement Costs

For mechanically inclined owners, replacing the thermostat yourself can significantly cut costs, though it carries risks if mistakes are made. Cooling system work affects engine longevity, so precision and safety matter.

• Estimated DIY cost: About $60–$150, mostly for the thermostat, any housing or gasket, and coolant.
• Tools needed: Basic hand tools (ratchets, sockets, screwdrivers), drain pan, possibly hose clamp pliers, and a funnel or vacuum fill tool.
• Risks: Air pockets in the cooling system, coolant leaks, or incorrect installation can lead to overheating and serious engine damage.
• Time required: A careful first-time DIYer might spend 2–4 hours including cleanup and proper coolant bleeding.

DIY can be economical if you are confident in following detailed service procedures and handling coolant safely, but many owners prefer professional service given the potential consequences of mistakes.

Factors That Can Increase or Decrease the Price

While the typical cost range is relatively narrow, specific circumstances can move your price higher or lower. Knowing the main variables helps you interpret quotes and avoid unpleasant surprises.

Regional Labor Rates

Geographic location has a strong influence on labor pricing. Urban metro areas and coastal regions tend to have higher shop rates than smaller cities or rural areas, directly affecting your thermostat replacement bill.

• High-cost regions: Major coastal cities and high-rent markets can push labor toward the top of the range.
• Lower-cost regions: Smaller towns or less expensive states often see shop rates on the lower end of the scale.
• Shop type: Franchise chains sometimes offer promotional pricing, while specialized or performance shops may charge more.

When comparing quotes, it’s helpful to factor in local cost-of-living realities rather than assuming national averages will match your exact situation.

Engine Type and Vehicle Condition

While the 2018 Hyundai Elantra is relatively straightforward, specific engine variants and the car’s overall condition can affect how easily the thermostat can be accessed and serviced.

• Engine configuration: Different engine options may have slightly different thermostat locations and access constraints.
• Corrosion or seized fasteners: Rusted bolts or aging hoses can turn a simple job into a longer repair if components break during removal.
• Previous repairs: Non-standard modifications, sealants, or incorrect past work can complicate disassembly and reassembly.

In most typical 2018 Elantra cases, these factors don’t significantly alter labor time, but they can explain occasional variations in estimates between shops.

Additional Services Performed at the Same Time

Shops sometimes recommend related cooling system maintenance while replacing the thermostat, which can raise the invoice but also improve long-term reliability. The value of these add-ons depends on your car’s age, mileage, and service history.

• Coolant flush: Replacing old coolant instead of just topping off can add $80–$150 but can be wise if coolant is aged or contaminated.
• Hose replacement: Worn or cracked hoses discovered during the job may add $30–$120 in parts and labor.
• Additional diagnostics: If overheating or temperature issues are complex, extra time may be spent checking fans, sensors, and water pump function.

While these services increase the total bill, combining them with thermostat replacement can reduce future labor costs and prevent repeat visits for related issues.

Signs Your 2018 Elantra’s Thermostat May Need Replacement

Understanding the symptoms of a failing thermostat helps you decide when it’s worth paying for replacement versus further diagnostics or additional cooling system repairs. Ignoring these signs can lead to more expensive engine damage.

Common Warning Symptoms

The thermostat typically fails in one of two ways—stuck open or stuck closed—both of which affect engine temperature. Modern vehicles like the 2018 Elantra often detect these issues electronically and log diagnostic codes.

• Overheating: Temperature gauge climbing into the red zone, especially under load or in traffic, often suggests a stuck-closed thermostat or another cooling issue.
• Engine running too cool: Gauge staying far below normal, particularly on the highway, may indicate a stuck-open thermostat.
• Check engine light: Fault codes related to engine temperature, such as P0128 (coolant temperature below thermostat regulating temperature), can point to thermostat trouble.
• Poor heater performance: Cabin heat not getting warm enough, especially in cold weather, can occur if the engine never reaches proper operating temperature.

If these symptoms are present, a thermostat replacement is often part of the recommended fix, though a competent technician will check for other potential causes before replacing components.

How to Get an Accurate Estimate

To avoid surprise charges and ensure you are paying a fair price, it’s worth spending a few minutes gathering quotes and asking specific questions about what each estimate includes. This is especially important if the car is out of warranty and you have flexibility in where you go.

Questions to Ask a Shop or Dealer

Before authorizing the repair, you can clarify details about parts, labor, and warranty coverage to compare value rather than just the headline price. This helps you understand whether you’re being quoted for the same level of service in each case.

• What is the parts cost and brand? Ask whether they’re using OEM Hyundai parts or aftermarket, and the price difference.
• How many labor hours are estimated? This lets you see how much of the quote is labor and compare to other shops.
• Is coolant included? Clarify whether the quote covers any coolant flush or just a top-off.
• What warranty is provided? Confirm coverage length for both parts and labor.

Having clear answers to these questions makes it easier to compare quotes and justify choosing a slightly higher or lower estimate based on overall service value rather than price alone.

Summary

For a 2018 Hyundai Elantra, replacing a faulty thermostat generally costs around $220–$400 at a professional repair facility, with the thermostat and related parts accounting for roughly $60–$150 and labor for about $150–$300, depending on location and shop type. Dealerships tend to sit at the upper end of that range, while independent shops often fall in the middle; a capable DIYer can typically complete the job for the cost of parts and coolant alone.

Key factors shaping the final price include regional labor rates, whether additional services like a coolant flush are performed, and the choice between OEM and aftermarket parts. If your Elantra is showing signs of temperature irregularities, overheating, or diagnostic codes tied to coolant temperature, obtaining a few detailed estimates and clarifying what’s included will help you manage both repair cost and long-term reliability.

How much does a dealership charge to replace a thermostat?

A dealership typically charges between $150 and $550 to replace a car thermostat, but this can vary significantly based on the vehicle’s make and model, labor rates, and whether additional parts are needed. The cost includes the price of the thermostat itself (which is generally inexpensive, ranging from about $20-$80) and the labor involved. 
Cost breakdown

• Parts: The thermostat unit and gasket are relatively inexpensive, usually costing between $20 and $80. Some modern or electronic thermostats can cost more, between $80 and $300. 
• Labor: The thermostat is a small part, but replacing it involves accessing it, which can be difficult depending on the vehicle’s design. The labor cost typically ranges from $120 to $220, assuming the job takes 1 to 2 hours. 
• Total: The total cost can range from about $150 to $550, depending on the labor rates at the dealership and the complexity of the job. 

Factors that can increase the cost

• Vehicle make and model: Luxury or sports cars may have higher labor rates or require more complex procedures, increasing the final price. 
• Additional issues: If the thermostat replacement reveals other problems, such as a cracked housing or a faulty sensor, the final bill will be higher. 
• Diagnostic time: Sometimes, a mechanic needs more time to diagnose the problem accurately before beginning the repair, which can add to the total cost. 

What to do

• Get an estimate from the dealership before authorizing the work. 
• If the estimate seems high, get a second opinion from an independent mechanic. 
• Ask the mechanic to explain the cost, especially if they quote a price at the higher end of the range. 

What are the common problems with the 2018 Elantra?

Top 2018 Hyundai Elantra Problems

• Stalling/failure to start due to crankshaft angle sensor failure.
• Hyundai Elantra service light activation upon headlight use and recurring tail light issues.
• Hyundai Elantra excessive wind noise from lower right corner of front windshield.

How much does it cost to replace a thermostat in a Hyundai Elantra?

The total cost to replace a Hyundai Elantra thermostat typically ranges from approximately $190 to over $500, depending on the car’s model year and the labor rates in your area. The thermostat part itself is relatively inexpensive, costing around $15 to $35, while the majority of the expense comes from professional labor, which can be an additional $100 to $150 in labor, plus potential diagnostics and shop fees. 
Cost breakdown 
This video explains how a thermostat works and what happens when it fails: 36sMy Auto LifeYouTube · Sep 7, 2024

• Parts: The thermostat itself, including any necessary seals or housing, can range from $15 to $35. For some models, you may also need to purchase a separate thermostat housing assembly for around $60. 
• Labor: This is the largest portion of the cost. The time it takes to replace a thermostat can vary, with most shops estimating the job at around 30 to 60 minutes. However, this does not include the time for diagnosis, which can add to the total. 
• Total Estimated Cost: Based on a combination of parts and labor, you can expect a total cost of approximately $190 to $500. 
  • For example, a 2017 Hyundai Elantra thermostat replacement is estimated to cost between $457.97 and $627.97 by one provider, including parts and labor. 
  • A recent user on a Reddit thread reported a quote of around $500 for the same job. 
  • Another provider estimates the total cost for a 2012 Hyundai Elantra at $407.05 to $563.96. 

What affects the cost?

• Model and year: The price and complexity of the job can vary depending on the specific Elantra model and its year. Some models may be more difficult to access, requiring more labor time. 
• Labor rate: Your final cost will depend on the hourly labor rate of the shop you choose. Rates can differ significantly between different shops in the same area. 
• Additional parts: Depending on the diagnosis, you may also need other parts, such as the thermostat housing assembly or coolant, which will add to the total cost. 
• Diagnostic fees: The repair shop may charge a separate fee for diagnosing the problem before starting the repair. 

How to save money

• DIY: If you are comfortable with car repairs, you can save a significant amount of money by replacing the thermostat yourself. 
• Get multiple quotes: Before committing to a repair, get quotes from several different shops or mechanics to compare prices.
• Ask about bundled services: If you have other maintenance needs, ask if you can bundle them with the thermostat replacement to potentially save on labor costs. 
• Check online parts stores: Online parts stores like Advance Auto Parts, AutoZone, and Amazon offer thermostats for as low as $15, which you can purchase and have a mechanic install. Make sure to confirm the correct part for your specific Elantra model before purchasing. 

How much is a thermostat for a 2018 Hyundai Elantra?

The range of prices of Thermostats for the 2018 Hyundai Elantra goes from $18.48 up to $32.99 for the most premium parts.