heating issues

[thesaint]

hi,

have done my coolant change, but my heater now does not work! fan etc.. all work, jsut blows cold air, i am assuming an air lock in the heater but, any tips on getting it sorted? did this a couple fo years ago and i seemed to be messing around most of winter trying to get it going and it just decided to spring into life just as spring
was arriving!

thanks

[mark_hat]

my friend,,
you need to bleed the system, just gone through the same thing,, there's a bleed valve on the thermostat housing,, be very careful with the valve, let the car run up to normal temp and release the valve, let the air out of the system, you'll most probably need to do this a few times,, it took me and my friend 20 mins to get it workin properly,,
good luck....

[thesaint]

thanks. i have fiddled with the a bleed valve on the water pump, i shall look at the thermostat tommmorow, its getting a bit nippy in the mournings now!

[Brianmoooore]

If you have a M20 engine, you are playing a very dangerous game of Russian roulette with your cylinder head! The car should not be driven in this condition!!

[mark_hat]

hi,,
As i said before it took us a good 20 mins to get the heat to come through, i was getting worried after 10 mins but it worked fine,,

[Morat]

The problem is that running an M20 without the cooling system being correctly bled is a good way to crack your cylinder head. They don't really take much overheating before they go.

[thesaint]

temp gauge has never gone past the middle! will go and have another fiddle!

[Morat]

The temp gauge may be inaccurate if the coolant isn't flowing correctly.

[Brianmoooore]

Temperature gauge reading is irelevant! If you drive a M20 engine in this condition, you will probably crack the head!!

[thesaint]

well i had a play and ther si no air coming out of the bleed valve was running for about an hour, coolant coming through nicely, but im still very cold!

[Chris-W]

Briefly crack open the outlet hose from the matrix a little (with gloves ideally) next time you try bleeding it,, should clear an air lock if any in the matrix.

[thesaint]

the matrix is in the passanger side in cabin?