my heating not working - where to begin

[Sancho]

do you mean the thermostat housed in the assembly where the rad cap is. would this be the problem for the front heating as well.

Im not having any overheating issues and the temp gauge is always steady once engine has warmed up..

im still leaning towards the heater core being blocked up. but why/how does heat get through to the rear.

Yes, that thermostat. Not likely to be the problem with the front heater, but temperature fluctuating with revs normally implies that the stat is letting water past too fast.

Front and rear heater matrixes (matrices?) are separate.

[Fargo]

this bleed valve mod, i did a search and couldnt find details, but from what you said i can cut the pipe going to the heating valve, and fit say a 22mm copper pipe fitted with a central heating drain off valve.
How did you then fill it, via a funnel ?.
If my heater core is plugged this would not clear it correct,



@ sancho, so really it wold be worth getting a new thermostat in anycase.

[fenman666]

heater mod

http://hiluxsurf.co.uk/forums/showth...r+bleed&page=3

[fenman666]

Funnel would do but I cut the bottom off a drinks bottle and siliconed a hose tail into the cap fitted some plastic tubeing ....... Basically when its fitted up and hung from the bonnet catch it looks like the surf is having a blood transfusion .....

[Fargo]

@ fenman, thanks.. and me being a gas man ive got all the bits i need lol.

whers the best place to fit it.

also bare in mind when i flushed i stuck the hosepipe on the hard pipe going from the bulkhead into the heater core and nothing came out the other end, it just backwashed back out the pipe i had the hosepipe on.

[fenman666]

Jeez that sounds as if there is a major blockage !!
If it was mine ...as a last resort I would take both hoses off heater matrix where they go through the bulkhead and attach a couple of lengths of hosepipe to the two ends, then fill the hosepipe with rad flush and let them soak for a while, keeping the ends of the hose above the level of the matrix .... worth a try ? Give it an hour then try flushing through either hose ...

One other thing ... you,ll laugh at this one ..... I had a heater matrix on a scenic which had a head gasket blow and let engine oil into the water system, blocking the heater matrix....... same method but I used washing powder mixed with boiling water, poured into the hoses and left for an hour ...flushed it and problem solved

[Fargo]

just so i got my terminology right, the heater matrix is the heating circuit (pipe runs etc).

As another test can i disconnect the two pipes going to the heater core (on the bulkhead) and join them together, then run the engine to make sure hot water passes through this circuit (engine side circuit if you wish)

Ive got some fernox central heating restorer somewhere i'll use that and inject it in the hard pipes on the bulkhead going to the heater core (cabin side circuit).


how hard is it to remove the heater core.

[BUSHWHACKER]

To get at the heater core you'll need to remove the glovebox and centre section of the dash. PITA job.
Before you do that though, is the flap on the heater motor assembly moving when you move the hot/cold slider control on the dash? There are two cables connected to the slider control arm, one goes to the shut off valve on the bulkhead and the other goes to a foam covered flap on the heater fan assembly.
The cable to the flap can sometime become kinked or un-cliped so the flap doesn't open/close allowing hot air into the cabin.
The heater hoses that are connected to the shut off valve on the bulkhead, are they soft and 'crunchy' when squeezed? They could be breaking down inside causing blockages and will need replacing.
The pipes leading to the rear heater are totally seperate from the rest of the cooling system, if it's working then you can forget about that part.
Here's how I fitted the air bleed fitting to the heater pipes......


Photo showing the hoses connected to the heater core, flush with the garden hose at these two points.

[lord lucan]

ive now drained and flushed through. removed the lever thing from the bulkhead and flushed through to make sure that was clear. removed both pipes from the bulkhead and a) hosepipe'd through the pipes flushing back through the circuit and coming out the bottom rad pipe that i removed, b) hosepipe'd into the hardpipes in the bulkhead which didnt flow water though.

So whats on the other side of the bulkhead behind the dash, is that where the matrix sits and would this be blocked do you think..

if you cant get a flow of water from the hard pipes on the bulkhead as you said above the heater matrix is blocked,keep hosing it from one pipe to the other till it goes free then fill the system with rad flush and follow the instructions on the bottle

[Fargo]

@bushwacker. I didnt know there weretwo cables coming from the one slider, I will chec, but yes the heater valve where the cable goes is moving and connected I have also removed and ckecked for flow.
@ lordlucan. Yes that is correct and is what I think the problem is. Hose one side and nothing comes through the other.

[BUSHWHACKER]

You should hear a clunk as you move the temp slider back and forth, if not then the flap isn't moving.

[stormforce]

You should hear a clunk as you move the slider back and forth, if not then the flap isn't moving.

a dirty thought has just gone through my mind reading that reply

[Fargo]

yes the flap is moving, quiet noiserly when i do it back and forth hard.

[lord lucan]

@bushwacker. I didnt know there weretwo cables coming from the one slider, I will chec, but yes the heater valve where the cable goes is moving and connected I have also removed and ckecked for flow.
@ lordlucan. Yes that is correct and is what I think the problem is. Hose one side and nothing comes through the other.

put the hose one side then the other you will clear the blockage

[Fargo]

then i await the weekend to blow my troubles away lol..