Heater valve changed, but no improvement ?

[graeme4130]

Hi All
As advised by many, tonight, I've been through the knuckle tearing pain of changing the heater valve on my 95 4.0hc, but it doesn't seem to have made any difference to the lack of heat or cold being produced.

New valve ready for fitting


fitted and ready to go ;



Problem is, the old valve seemed to actually be OK when I took it out, so I'm still not getting either hot or cold air through the heaters irrelevant of dial position. I only seem to get a warmish blow rather than the proper 'leg burning' hot I've experienced in other Chims
I've tested the dial, and the valve goes from fully open to fully closed OK, but doesn't seem to effect the air temp
Not sure if it's relevant, but when I removed the valve, it seemed that there was no coolant in the upper hose above the valve, but some below
I've just bled the air out the system as per the manual, but it's not made a difference.

If anyone could give me some advice, then I'd be eternally grateful as winter weather's coming up on us soon, and driving on those chilly sunny days is going to be painful without a heater..

Thanks in advance for your advice

Graeme

[MADMAX2]

Pop out your passenger wing indicator and turn your heater on if you feel air from the hole a pipe has come off failing that check all pipe fittings if you can hear the heater motor blowing the problem is to the vents

[Hedgehopper]

How did you bleed the system? I found the only way to get the air out of the heater was to remove the top heater hose at the back of the engine by the bulkhead. This is just about the highest point of the system and air seems to get trapped there.

[graeme4130]

The heater blows ok in accordance with the fan knob, but it's just the temp that doesn't change

Re, having air in the heater matrix/box, wouldn't that get blown out by water from the pump ?
I bled the system with the highest point being the top of the radiator and also the swirl pot. I'll have a go at the heater hose later

Is there a way of checking if the thermostat is opening (would this effect the heater) or if the water pump's just not working correctly
The radiator's only 12 months old and seems good condition back and front, but the car does run quite hot (generally up to around 90-92deg most of the time- even after the fan cuts in)
Cheers
Graeme

[WOO5IE]

Hi Graeme,

Have you tried feeling the heat of the pipes either side of the new valve. It could be that a blower pipe has come off so you dont feel hot air from the vents.

The heater pipes run along the off side rocker cover in the engine bay so you could see if they are hot as well.

A previous owner may have looped back to back the flow and return heater pipes to keep the cockpit cooler so that no water flows through the heater matrix.

[graeme4130]

WOO5IE said:

Hi Graeme,

Have you tried feeling the heat of the pipes either side of the new valve. It could be that a blower pipe has come off so you dont feel hot air from the vents.

The heater pipes run along the off side rocker cover in the engine bay so you could see if they are hot as well.

A previous owner may have looped back to back the flow and return heater pipes to keep the cockpit cooler so that no water flows through the heater matrix.

Hi Woosie
The blowers still blow air ok, just always luke warm

I'll check the various hoses tonight

[graeme4130]

Right, tested all the hoses tonight
Everything seems ok, hoses on both sides of the valve were very hot
Thermostat kicked in a little late at around 85, so I've ordered a replacement and otter valve kicked off radiator fans at 92ish no prObs
Still, heater only runs Luke warm on 'hot' and Luke warm in 'cold'
If the valve pipes are hot, could I still not be getting heat into the matrix ?
Cheers for your advice so far
Gh

[Englishman]

Have you ever reversed flushed the heater matrix? If not worth trying. Had an MGB GT (sad I know!) a long time ago now that exhibited similar issues. Was simply filled with years of crud restricting the flow. Once fully flushed the heater was fine.

[graeme4130]

No, never tried it
Is it hard to do, do you know how would I do that in a Chim ?
Sorry for the questions and thanks in advance
Gh

[Englishman]

Simple to do, in theory, but you'll need access to the two pipes to and from the heater matrix. Had a quick look at 'the bible' and it doesn't really help. If you can find where they connect in the engine bay I suspect that'd be far easier then under the dash.

[graeme4130]

Englishman said:

Simple to do, in theory, but you'll need access to the two pipes to and from the heater matrix. Had a quick look at 'the bible' and it doesn't really help. If you can find where they connect in the engine bay I suspect that'd be far easier then under the dash.

Thanks for the help, I'll have a look at that one tonight
Was blimmin cold driving home from the TVROC meet last night with the roof down and an inefficient heater

The other though might be that the water pump maybe isn't as efficient as it could be and the matrix just isn't getting enough water ?
The engine tends to run around 90deg all the time
I've checked the bible, and this is the top end of the scale

[TJC46]

graeme4130 said:

Englishman said:

Simple to do, in theory, but you'll need access to the two pipes to and from the heater matrix. Had a quick look at 'the bible' and it doesn't really help. If you can find where they connect in the engine bay I suspect that'd be far easier then under the dash.

Thanks for the help, I'll have a look at that one tonight
Was blimmin cold driving home from the TVROC meet last night with the roof down and an inefficient heater

The other though might be that the water pump maybe isn't as efficient as it could be and the matrix just isn't getting enough water ?
The engine tends to run around 90deg all the time
I've checked the bible, and this is the top end of the scale

The 2 heater hoses run at the back of the engine over the bellhousing. You should be able to undo the hoses from the heater rail that runs along the right side rocker cover, at the highest point, almost under the bulkhead. Do it carefully this way and you wont lose any fluid from the engine/rad etc. Unsure which is the feed/return but flush both in turn until clear and cleanish water coming out.

I find a very good way to refill the cooling system, especially if it has been part or fully drained, is to undo the hose from the top heater rail, the hose itself goes into the inlet manifold. Now raise this hose up as high as poss, [i usually tie it to the rod holding the bonnet open]. Use a funnel and fill thru this hose.You are now filling at a higher point than any part of the cooling system. Undo the nut on the rad to vent air and when water starts coming out tighten the nut. Contnue filling slowly, some water may start to come out of the open end on the heater rail, but if you fill slowly this shouldnt be a problem. Now check the level in the expansion tank and keep filling thru the funnel/hose, until the water level starts to rise in the expansion tank to its usual level. [this seems to vary from car to car, usually 25mm to 50mm from the bottom.]
Replace the heater rail hose and check the level in the expansion tank the next couple of times you use the car and top up if necessary.
I had a few rad problems earlier in the year, and had to drain all the system at least three times during this period, whilst trying to sort the problem.Refilling using the above method worked perfectly every time.
This method came out of necessity as there is no way on earth, i can undo the nut on top of the swirl tank.

[graeme4130]

TJC46 said:

The 2 heater hoses run at the back of the engine over the bellhousing. You should be able to undo the hoses from the heater rail that runs along the right side rocker cover, at the highest point, almost under the bulkhead. Do it carefully this way and you wont lose any fluid from the engine/rad etc. Unsure which is the feed/return but flush both in turn until clear and cleanish water coming out.

I find a very good way to refill the cooling system, especially if it has been part or fully drained, is to undo the hose from the top heater rail, the hose itself goes into the inlet manifold. Now raise this hose up as high as poss, [i usually tie it to the rod holding the bonnet open]. Use a funnel and fill thru this hose.You are now filling at a higher point than any part of the cooling system. Undo the nut on the rad to vent air and when water starts coming out tighten the nut. Contnue filling slowly, some water may start to come out of the open end on the heater rail, but if you fill slowly this shouldnt be a problem. Now check the level in the expansion tank and keep filling thru the funnel/hose, until the water level starts to rise in the expansion tank to its usual level. [this seems to vary from car to car, usually 25mm to 50mm from the bottom.]
Replace the heater rail hose and check the level in the expansion tank the next couple of times you use the car and top up if necessary.
I had a few rad problems earlier in the year, and had to drain all the system at least three times during this period, whilst trying to sort the problem.Refilling using the above method worked perfectly every time.
This method came out of necessity as there is no way on earth, i can undo the nut on top of the swirl tank.

Thanks very much, I'll have a go at that later today and report back
I always found it odd that the filler points wern't the highest point, so this makes perfect sense
Cheers for taking the trouble to reply in so much detail
Graeme