Heater in 2006 lexus is 250 does not heat up unless you are driving at speeds over 40 checked coolant level and was good wondering if there was anything else that could i can check

Check the coolant level first. Make sure it is full. Take a look at the condition of the coolant. It should be bright red, green, or yellow depending on the type of coolant. If it is dark, rusty, or muddy than it is likely that the heater core has plugged do to the lack of maintenance of your cooling system .

The good news is the heater hoses can be removed from the heater core and the heater core can be back flushed to try and clean it out. This works 90% of the time. If heat returns than flush the cooling system to help prevent it from happening again. If heat still does not return than the heater core would need to be replaced. $$$$$

this vehicle may have a manual valve that controls the coolant flow to the heater core. Look for the heater hoses near the fire wall. The valve is usually inline with one of the hoses and will have a cable attached. If you see it make sure the cable is moving when you turn the heat select knob from full hot to full cold.

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First off check your Coolant level. If it is low, you will not get any, or you may get a little heat. If the Coolant level is good, you will need to check, or have someone check to see if you Thermostat is stuck open. If Thermostat is working properly, then your heater core must me suspected of being blocked . Have someone back flush the cooling system with a chemical flushing additive. If this gets you some heat, but not as good as it should be, replace the heater core. Hope this helps.

Check the coolant level. Also check for leaks. Good level and no leaks. Replace the water pump.

probably a cracked head or blowed head gasket...how many miles on the car???

thermastat maybe sticking or to high of a temp thermastat. change it to recommended type from auto parts store and you will have heat.

IT COULD BE EITHER LOW ON COOLANT CHECK THE RADIATOR WHEN IT IS COLD OR THE HEATER CORE IS PLUGING UP YOU CAN CHECK THAT BY FEALING THE HEATER HOSE IF ONE IS HOT AND THE OTHER IS EITHER COLD OR WARM THEN THE HEATER CORE IS PLUGED CHECK COOLANT LEVEL FIRST

check your thermostat and upper and lower hoses when your idling to see if coolant is passing through your engine

look at the heator core and check the thermostat

it takes quite a while for a diesel to warm up by just idling in order to produce any heat.you have to put them under a load (drive it), before you will get any noticeable heat.if you have a block heater, plug it in 4-5 hours before you plan on driving it and that will definitely help produce interior heat quicker.

bad thermostat heatr air diverter valve or low on coolant