Subaru Impreza WRX STI Over Heating

Subaru Impreza Overheating? Here’s 6 Common Causes

In this post we will go through the possible causes of a overheating Subaru Impreza and what you should do if your car is overheating.

Overheating-1 Subaru Impreza Overheating?  Here's 6 Common Causes
Impreza Overheating

Overheating is commonly caused by the following

  • Faulty Water Pump
  • Coolant leak and level too low
  • Blocked Radiator
  • Thermostat stuck in closed position
  • Radiator fans not working
  • Head Gasket failure

Carry on reading to find out more.

Usually the first thing you will notice if your Subaru is overheating is the dash temperature gauge rising above its normal range, Subaru cars usually run with the temperature gauge pointer about half way between the min and max marks, when up to temp. If you notice the gauge rising above this level then there are a few things you can do, it is important not to run the car if the temp gauge shows the car is very hot or other damage could be caused.

Initially if it is practical pull over in a safe place and pop the bonnet,It may be immediately obvious what the problem is, for instance if you have a split radiator hose quite often this will spray coolant all over the engine bay if this is the case you will obviously need to get this repaired before continuing.

If there is no obvious problem with the engine running listen and look to see if the radiator fans are on,be careful if the fans are spinning not to put anything close to them they could take you fingers off.With the air con off the radiator fans will cut in when the engine temperature reaches 95 deg centigrade, and should only stay on for about 30 seconds depending on the ambient air temp.

If the fans are on constantly (with the air con off) then the fans can not bring the coolant temp down enough for the fans to cut out, this happens at 89 deg c. So this indicates a problem.If the fans are not running but the temp gauge shows a hotter than normal engine the fans could be faulty or you could have a blown fuse. whilst under the bonnet check for any visible coolant leaks as this could be your problem.

Do not under any circumstances remove any of the radiator caps whilst the car is hot you could scold yourself. If the fans are not running try putting the air con on (if fitted) and re check to see if the fans are on if they are leave the air con on and see if that brings the coolant temp gauge down.

Next you need to check that there is plenty coolant in the system but you must wait until the engine is cool, if you open the cap whilst the engine is hot it is pressurised and could spray boiling water all over you causing burns….dont do it. wait until the engine is cool.

If the car has two caps then remove the highest one (the one on the engine expansion tank) check that you can see coolant near to the top of the tank, if not you must top it up if possible.

When you are happy there is no leaks and the coolant level is ok then you can attempt to drive the car again, this time leave the interior heater on hot and on full fan speed this can help keep a overheating car cool. if for instance the thermostat or radiator were blocked then using the interior heater as a means of cooling the car is a good temporary solution.

If the car still overheats then you may have to consider getting recovered, as previously stated if you run the car too hot it can cause damage.

To Recap – 6 Common Causes of Overheating

  • Faulty Water Pump
  • Coolant leak and level too low
  • Blocked Radiator
  • Thermostat stuck in closed position
  • Radiator fans not working
  • Head Gasket failure .

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