405 Heater...

Its winter?

This HAD occured to me :)

Seriously tho, it worked fine last winter, and even when it does get warm, never gets hotter than luke warm...

Where does the engine temp gauge run? Should be towards 12 o clock. If its well down- change the thermostat to get the engine running at operating temperature.

Tim..

Engine temp is fine and normal, 12 o'clock indeed (about 90c on the gauge)

It's quite likely your heater matrix is blocked. Takes the hoses off leading to the heater matrix and push a hose pipe up one. Then give it a good blast of water. Repeat in both hoses a couple of times. You should find that this improves things. It certainly did for me. A coolant flush is also likely to help perhaps after the above.

Not on the 405. The coolant permanently circulates through the matrix - if his was blocked, then his engine would be overheating.

When you set the blower temperature with the dial, a motorised flap moves to direct the air through the matrix (or not). It's likely that the motor has jammed/bust/crapped - common fault.

Not an option on the Mk2 405. The *ENTIRE* dash has to come out to access the matrix. It's a day's work taking it out, and another day's work putting it back !

The matrix is usually on a bypass so the coolant circulates even if the matrix is blocked. It doesn't have the capacity for all the coolant to flow through it. That's also why they are prone to block up because there really isn't that much pressure on them.

Not a big deal - so you just disconnect the hoses at the engine end.

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There is a hose that goes from the engine to the heater, you don't need to remove the dash.

-- James