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Toyota matrix 2003 heater heats badly and cools when engine speed drops. I suspect something in vacume control

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Heater heats badly and cools when engine speed drops<<<<?

Heating GOOD OR DECENT GOIN DOWN THE ROAD but not at SLOW speed or stoplight
This is useualy a sighn of low coolant,as at low speed the Flow slows downand allows any AIR Pockets to Form thus causing
Heater NOT to GET COOLLANT, SYSTEM MUST be topped off with Temperture Selector dial ON HOT And ENGINE at Operating Temp-NICE & HOT this way cooolant fills all Voids and AIR. Pockets

IF there is a Bleeder Valve at TOP of Thermostat Housing then after first Procedure, Close System with Radiator CAP then Open Bleeder SCREW let it Flow till NO AIR comes Out then Close Bleeder screw Tight.

Posted on Jan 16, 2009


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