How to Run an Engine With No Heater Core

Running a car without a heater, or bypassing the heater core, is OK to do in hot climates if the heater is rarely used and serves little or no function. Heater cores can leak and damage interior carpets. When leaks happen, often a temporary bypass is called far, especially on cars where replacing the heater core means removing the dash.

Things You'll Need

  • Phillips-head screwdriver
  • Hose clamps
  • Hose splice
  • Razor knife
  • Locate the two heater hoses going from the engine into the firewall. One is the supply hose- the other, the return. Remove the old clamps, slice the hose along the length of the heater core pipe and the hose will easily come off.

  • Trim and prepare the hoses for the splice. Hose connectors, sometimes called hose splice, come in assorted sizes. Take a piece of the trimmed hose to the auto-parts store to compare. Be certain the connector and clamps are sized to fit.

  • Install the connector between the two heater hoses. This creates a loop that will allow the coolant to bypass the heater. Tighten the hose clamps. Be certain that the hoses will not lie next to exhaust components or can be chafed against sharp objects.