How To Replace A Faulty Vehicle Thermostat

13 February 2017
 Categories: , Blog

If your vehicle takes a longer time to start, it does not reach normal temperature of 200 degrees F, or it overheats fast, the thermostat may be the culprit.The thermostat prevents the coolant from entering the radiator until the engine warms.

It helps control emissions and wastes to the engine by warming it up slowly.It isn't hard to replace a thermostat yourself. Here are tips to replace a vehicle thermostat.

Prepare to Work

For this project, you need:

  • work gloves
  • disposable containers
  • old thick rag or bath towel
  • emery cloth
  • putty knife or scraper
  • flat-blade screwdriver
  • open-ended wrench
  • gasket
  • gasket sealer
  • spray lubricant
  • new thermostat

Prop the hood open and locate the thermostat. Most vehicle thermostats are located near the water pump below a housing with a two inch long hose attached. Get the model number, and use it to buy a replacement thermostat.

Drain Radiator Coolant

Let the vehicle cool, if it has been running. Hold the rag or towel over the radiator cap. Listen as the pressure slowly releases. Detach the cap when the sound stops.

Set a disposable container under the radiator tap or bottom hose. If you plan to reuse the coolant, use a clean container. Drain the coolant, until it gets below the housing. Clean up spills immediately, since it is toxic, and  the sweet smell attracts animals.

Remove the Old Thermostat

Keep a container under the hose. Detach the bolts on each side of the hose with a screwdriver or wrench. Lubricate bolts that are hard to remove.

Some hoses attach by clamps with clip clamp. Gently twist the hose until it detaches from the thermostat cover.

Loosen the housing bolts with the wrench. Detach the cover and thermostat. Use the putty knife or scraper to scrape off the old thermostat cover gasket.

Take care not to scratch the housing, or let any gasket remnants fall in the thermostat openings. Remove traces of the gasket with the emery cloth.

Install the New Thermostat

Set the new gasket in place with the spring mechanism pointing down. The top of the thermostat will fit into the recessed area.

Coat the housing base with gasket sealant. Set the new gasket in place; ensuring the bolt holes line up. Let the sealant dry before you start the vehicle.

Refill the coolant, and reattach the radiator cap. Reinstall the thermostat cover and hose. Discard any rags you used in a disposable plastic bag.

Test the replacement thermostat. The engine should warm up to  normal temperature. If you don't trust your skill, or the vehicle still doesn't work, take it to a mechanic.