Rx 300 Heater

[tomannis]

My wife has an RX300 -2003 model. Has had it for 1 year, all fine till now. When on the move the heater works fine, but when stopped at lights or idling just blows cold air. Any ideas how to fix this?

Thanks

[Tyrosman]

Possibly a partial blocked heater matrix. When idling the (engine driven) coolant pump is operating at a low speed therefore the pumping action is at reduced pressure.

Under this condition a partially blocked matrix may not be receiving sufficient heated coolant flow.

At normal running speed the pumping pressure is increased, thereby forcing sufficient coolant through the matrix to produce heat.

This may not be the cause but is, at least, a line of thought to follow.

Let us know if you do discover the fault and also the remedy.

Good luck

Barrie

[tomannis]

OK Barrie

Many thanks for your suggestion-I'll run it into my local friendly garage (£45.00 ph labour charges!!) and get them to check it out- I expect the heater matrix is buried deep in the engine,

Tom