# Thermostat Replacement in Upland > No heat or engine running hot? Route 66 Auto Repair in Upland replaces thermostats with the correct rating, a new seal and a full air purge. Source: https://route66autorepairshop.com/cooling-heating-ac-services/thermostat-replacement Updated: 2026-09-17 Business: Route 66 Auto Repair, 1775 W Foothill Blvd, Upland, CA 91786, (909) 608-7699 Hours: Monday to Friday 8 AM–5 PM, Saturday 8 AM–2 PM, Sunday closed **TLDR:** A new thermostat must match the **temperature rating** your engine uses. We fit a new seal and **purge the air** so the job is done right once. A thermostat that is stuck open leaves you with weak heat and a cold gauge. One that is stuck closed can overheat the engine within miles. Route 66 Auto Repair in Upland replaces thermostats with the temperature rating your engine calls for, fits a new seal, refills with the coolant your engine specifies and purges the air, so you get a steady gauge and full heat. ## What are the signs you need a new thermostat? - Heater that blows lukewarm even after a long drive - Temperature gauge that rises quickly into the red - Gauge that stays low on the freeway - Coolant leaking at the thermostat housing - Check engine light for a slow warm-up ## What makes a thermostat job done right? The part matters. A thermostat with the wrong temperature rating can make the engine run too cool or too hot, and some have a jiggle valve or bleed hole that must face a certain way. Some engines use a thermostat built into the housing. If yours does, the estimate shows the assembly. The seal and the fill matter too. A new gasket or O-ring goes in every time. After refill, trapped air has to be purged, or the new thermostat can stay closed because it is sitting in an air pocket. If your engine uses an electronic thermostat or the cause is not yet clear, see [cooling system thermostat valve repair](https://route66autorepairshop.com/cooling-heating-ac-services/cooling-system-thermostat-valve-repair) for the diagnostic side. ## Our thermostat replacement process 1. **Confirm the need:** We check temperature data and heater output to confirm the thermostat is the cause. 2. **Drain and remove:** Coolant is drained below the housing, and the old thermostat and seal are removed. 3. **Install correctly:** The new thermostat is fitted in the right orientation with a new seal, and the housing is torqued to spec. 4. **Refill and purge:** Coolant is refilled, air is purged, and the engine is run hot to confirm the thermostat opens. ## What's included in thermostat replacement - Temperature and heater output check - New thermostat with the correct rating - New gasket or O-ring - Coolant refill with the type your engine specifies - Air purge and hot run verification ## Is a bad thermostat urgent? **Need now:** - Engine overheating - Coolant leaking from the housing **Need later:** - Weak heat in warm weather with a normal gauge - A slow warm-up code with no other symptoms ## How pricing and timing work Price depends on where the thermostat sits and whether it is a stand-alone part or built into a housing. Some are easy to reach. Others need other parts removed first. Your written estimate comes before any work, and thermostat jobs are often done the same day when the board allows. AAA members get 10% off parts and labor, up to $75. If the housing is cracked, [thermostat housing repair](https://route66autorepairshop.com/cooling-heating-ac-services/thermostat-housing-repair) is added as its own line. ## After the repair The gauge should settle in its usual spot within a few miles, and the heater should get hot. Check the reservoir cold for a few days. If the gauge moves oddly, call [(909) 608-7699](tel:+19096087699) and we will recheck it at the front of the line. ## Frequently asked questions ### Can I use a cooler thermostat to help in the summer? It usually does not help and can cause codes and poor fuel economy. We use the rating your engine was designed for. ### Should I replace the thermostat with the water pump? It is often a good time, since the system is drained. We quote it as an option and let you decide. ### Why did my car overheat after a thermostat change elsewhere? Common causes are trapped air, a thermostat installed backward, or a wrong part. We check all three. --- Call (909) 608-7699 or visit https://route66autorepairshop.com/contact for a written estimate.