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Thermostat Housing Replacement Cost

Know what price you should pay to get your vehicle fixed.

The average cost for a thermostat housing replacement is between $139 and $322. Labor costs are estimated between $70 and $245 while parts are priced between $69 and $77. Estimate does not include taxes and fees.
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What is an Engine Coolant Thermostat Housing?

During normal operation, an engine produces a lot of heat. The cooling system makes sure that the engine runs within a consistent temperature range without overheating. A mixture of coolant and water is circulated through the engine block to absorb excess heat. It is routed out of the engine and through the radiator, where its temperature drops before it enters the engine again. The coolant is moved through the system by the water pump, driven by a serpentine belt on the front of the engine. And the temperature is regulated with a thermostat placed in the path of the coolant. The coolant in the system needs be kept within a specific range. The engine coolant thermostat is responsible for this job, and the thermostat housing is where the job is done.

How do Engine Coolant Thermostat Housings work?

The thermostat in the engine is located in the path between the engine and the radiator. When the engine is cool (below normal operating temperature) the thermostat remains closed. This allows the coolant to circulate through the engine, but not to the radiator. When the temperature of the engine increases to the top of its operating range, the thermostat opens and allows coolant to travel to the radiator, where the fluid is cooled down before returning to the engine. The thermostat housing is where the thermostat is held. It is usually connected to the upper radiator hose near the water pump, but sometimes it is on the lower hose.

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What are the symptoms of a bad Engine Coolant Thermostat Housing?

If a vehicle is overheating, a bad thermostat could be the problem, and a damaged thermostat housing is more likely to produce a coolant leak, either from a cracked or warped housing or a failed seal to the engine. The thermostat housing can be made of metal or plastic. And the housing can be a stand-alone part that is separate from the thermostat, or (on later model vehicles) can be integrated with the thermostat and replaced as a single unit.

Can I drive with a bad Engine Coolant Thermostat Housing?

If the coolant thermostat housing is broken or leaking, it should be replaced as soon as possible. If the coolant level or size of the leak is sufficient to cause the engine to overheat, the vehicle should be pulled over immediately and should be towed to a trusted repair facility. In some cases, an Electronic Control Module (ECM) will force the engine into emergency "limp" mode, effectively idling the engine so that the vehicle cannot be driven fast or far. Eventually the ECM will shut down the vehicle completely. A low coolant warning light should appear on the dashboard to alert the driver that the coolant level is low well before the engine overheats, and the check engine light will likely appear denoting overheating or thermostat performance problems.

How often do Engine Coolant Thermostat Housings need replacement?

The thermostat housing on many vehicles should outlast the thermostat. In fact, it is designed to last the lifetime of the vehicle. But, sometimes the housing cracks due to the constant heating and cooling, coupled with the movement of the rubber coolant hose attached to it. On some vehicles, the housing and the thermostat are integrated and need to be replaced as an assembly, so the replacement of these thermostat housings would be performed at regular scheduled maintenance intervals. Also, the housing should be inspected for wear or damage if the engine overheats or any time the thermostat or radiator hose is replaced.

How are Engine Coolant Thermostat Housing issues diagnosed?

A damaged thermostat housing will leak engine coolant when the engine is up to operating temperature. The leak could originate from a crack in the housing, or it could come from a broken seal between the housing and the engine. Thermostat housings with rubber seals will need to be inspected for warpage in the event of a leak at the seal, and if no warpage is found, the runner seal can be replaced.

How are Engine Coolant Thermostat Housings replaced?

The thermostat housing is replaced once the engine has cooled down completely. A technician will unscrew the fasteners that hold the housing in place and remove the old part. The gasket or sealing material is cleaned from the mounting surface, and a new seal is installed. Once the new housing has been installed, the engine is started and brought up to temperature. Any lost coolant is replaced. If the thermostat is connected to the lower radiator hose, the technician will have to drain the coolant before removing the thermostat housing. In either case, once the coolant has been restored, any air that is trapped in the cooling system must be removed. Sometimes, a technician will use a special vacuum tool to remove the air before adding the coolant.

RepairPal Recommendations for Engine Coolant Thermostat Housing issues

RepairPal recommends that the cooling system be thoroughly inspected by a qualified technician at a trusted repair facility as soon as possible when signs of overheating or coolant appear. Also, ensure you are following the factory scheduled maintenance for the vehicle as the thermostat housing may be part of these services.

What to look out for when dealing with Engine Coolant Thermostat Housing issues

An engine in a late model vehicle is designed to run somewhere between 185 and 220 degrees. But the fluid in the cooling system can rise well in excess of 220 degrees when the engine overheats. This produces steam that will cause severe injury from scalding if the system is opened when hot and under pressure. Burns are possible as the engine components are also at a high temperature. Extreme caution should be exercised when working on a hot engine, especially one that is overheated. If steam is seen coming from under the hood, the engine should be allowed to cool for at least a half hour before the hood is opened, and the radiator cap or coolant reservoir cap should not be removed until the engine is cool enough to touch with a bare hand.

Can I replace the Engine Coolant Thermostat Housing myself?

The cooling system is typically serviceable by the DIY mechanic, however, following guidelines for properly bleeding the engine coolant system of air is mandatory to prevent overheating and damage to the engine. If the thermostat housing has warped, cracked, or leaked with no other issues to the cooling system, it can be replaced easily by nearly anyone who follows proper safety, replacement, and bleeding procedures.

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