Still no heat

[Barreti]

Eyup,

Now that I've got the motor blowing a reasonable amount of air into the car, I find I can't actually get much heat out of it.
I've checked the motor and valve are working ok, and both tubes leading to the heater are getting hot so I suspect its one of two things

a) the heater matrix has an air lock
b) the heater flap isn't moving or sealing very well inside the heater box

if its b) it can bks for a while

but if its a)
I've heard of funny tricks with Range Rovers where you tip the car up at one end then pump water through the matrix to make sure there are no air locks.
Does anyone (AntonyJ >? ) know if there is a trick to getting air out of the matrix or if flushing through the two tubes in the passenger footwell is enough to get them out.

Or any other ideas what it might be?

[Wildfire]

Wear more clothes?


Seriously if you find a way to improve the heater/blower let me know. I freeze even with it on max!!

[dnb]

There's no flap for heat selection. It uses a motorised valve on the water input to the matrix.

Obviously this isn't ideal, so I designed another heater box which I'm testing at the moment.

[Barreti]

dnb said:

There's no flap for heat selection. It uses a motorised valve on the water input to the matrix.

Obviously this isn't ideal, so I designed another heater box which I'm testing at the moment.

Isn't there? Good god. Thanks dnb, obviously got my wires crossed.

Righto, so there are 2 valves, one attached to a water tube, which is the one I guess you are talking about dnb, and one which operates something inside the heater box. What does this do - just direct air up to screen or down to feet and thats all?

Is the matrix inside the heater box stood vertically and therefore will bleed air out easily, or is there a trick to it? I've got good air circulation but can't get heat. Its odd because I'm sure I used to have exactly the opposite

[HRG]

Does the temp vary either side of the valve when you operate it? The insides failed on mine and even though it looked like it was turning from the outside the valve was stuck inside.

[AntonyJ]

Barreti said:

dnb said:

There's no flap for heat selection. It uses a motorised valve on the water input to the matrix.

Obviously this isn't ideal, so I designed another heater box which I'm testing at the moment.

Isn't there? Good god. Thanks dnb, obviously got my wires crossed.

Righto, so there are 2 valves, one attached to a water tube, which is the one I guess you are talking about dnb, and one which operates something inside the heater box. What does this do - just direct air up to screen or down to feet and thats all?

Is the matrix inside the heater box stood vertically and therefore will bleed air out easily, or is there a trick to it? I've got good air circulation but can't get heat. Its odd because I'm sure I used to have exactly the opposite

As you say Ian there are two motors on the precat system.
One lets the water flow through the matrix, the other controls the flap in the heater box.
This flap either send the air up to the screen and whichever dash vent(cant remember) OR down to the under dash vents.
Only problem is ,on the precat heater box this system is crap.The flap doesnt seal properly and as you know the orignal air movement is poor.

The later 500 heater boxes have a much better flap. Wish I had known this when I had mine out !!!

[dnb]

I'll try and post some pics of my original 500 heater box. It's not that much better IMO.

You're right about the 2 motors - one is a water valve, the other is a flap to direct air to the screen or the dash/feet vents.

On the 500 there is a 3rd motor near the battery to select if the air comes from outside or inside the car. This also doesn't work terribly well...

[Barreti]

Here we are again then.
I took the Griff out for a blast today so I got to check the water pipes. They are both hot, but I'm still only getting vaguely warm air into the car so I'm

Here's another thing too - the dials are steaming up.
They've always steamed up a little bit - especially the rev counter for some odd reason - but now they are all doing it and its quite pronounced in the speedo and rev counter.

Is this part of the problem, or another one?
Leaky heater matrix is my guess.

Noooooo, I will NOT take out the entire dash.

[AntonyJ]

Barreti said:

Here we are again then.
I took the Griff out for a blast today so I got to check the water pipes. They are both hot, but I'm still only getting vaguely warm air into the car so I'm

Did you check further back than the bypass section? If the matrix is blocked then this allows the water to flow still.

Here's another thing too - the dials are steaming up.
They've always steamed up a little bit - especially the rev counter for some odd reason - but now they are all doing it and its quite pronounced in the speedo and rev counter.

Mine steam up a bit too, but nothing excessive.

Is this part of the problem, or another one?
Leaky heater matrix is my guess.

Is the coolant level going down? Are the carpets wet either to the left or right of the passenger footwell?

[Colin RedGriff]

If both the input and output pipes to the heater are hot then hot water is flowing in and out of the matrix unit.

It the air coming out of the blower is not hot then I can only conclude that either
1. The main part of the matrix is blocked but still allowing the hot water to feed in and out but bypassing the actual part of the matrix that the air flows through;
or

2. The air is not flowing over the matrix at all. Don't know enough about the air box to be able to say if this is possible.

Hope that helps

Colin

[Gooner]

Water could be flowing through the matrix, but only part of it if the rest is blocked by an airlock. So you still might not be getting much heat.

I did have an airlock in the heater, went through the full procedure for bleeding the cooling system as per the Bible a couple of times and eventually dislodged it. Don't know if you've tried this but it involves loosening the big brass screw on top of the engine as well as the bleed valve on the radiator - best to look in the Bible as the sequence is quite important I think.

IMHO

gooner

[2Munkys]

It can also be symptomatic of the general cooling system being way too low Ian.