Heater series 1 not working
 

Hello all!

I thought I open a separat thread for an annoying issue. No heater working at all.

I think I may have the answer already, but I also want to get to know the system a bit more.
I currently do not have any vacuum on the system, due to the engine transplant I just didn't come to it yet.

Is that the cause? If so, what does the vacuum control? I really can't figure out how the system works, so any help and insight would be helpful!

I felt the hoses going to the heater and back, and both remain cold. There is no flow through the heater radiator it seems. From these hoses, I took off the heating for the LPG reducer. These do get warm, so there is hot water in the hoses, it just doesn't flow through the heater radiator.

Any help and insight greatly appreciated! :-)

you need to have vacuum to actuate the Heater Valve.

Okay, that's something that crossed my mind. Again, I know that applying a vacuum will solve a lot probably. And I will do this, tomorrow or so. But as I am lost some control buttons in my build, I want to know the system in order to figure out how I can redo the controls. So, for example, where is the heater valve?

the Heater Valve in the XJ is usually at the center of the firewall/bulkhead area. A vacuum hose connects to it. I am not very familiar with the Series 1 XJ climate system.

run the engine, have someone turn the Heater Control ON and OFF, you should see the heater valve's linkage moving (opening and closing), but again, you need vacuum for that to happen.

So, would this be the heater valve:
https://lh4.googleusercontent.com/ZL...Y=w913-h685-no

I thought this was a fresh air valve...?

I somehow find it strange no hot water is running throught the heater radiator. As I have the AJ6 engine in my series 1, things are a little different, but I have hoses with hot water all the way to the firewall, but there just is no flow. Does the heater valve control that?

As far as I can see, the valve in the picture above only controls a flap under the front windscreen right? behind that metal flap, I can actuall feel a radiator (not sure if heater or aircon) but that rad remains cold.

that looks like a Vacuum Servo (Valve).

the following picture shows the system, (photo courtesy of SNG Barratt USA)

if you want to study all the Heater system parts, click the link below:

SNG Barratt - The Ultimate Jaguar Parts Specialist

The last picture looks to be a servo valve to open the fresh air vent in the front plenum chamber, (underneath the chrome cover on the scuttle panel). The heater valve will have coolant pipes running into it, (two, one in and one out). These early Jaguar heaters were run on engine vacuum, and carried on from the earlier 420G. If there is no vacuum, nothing will work properly. Other thing to bear in mind is that a leak in a vac line will affect the engine running as it becomes an alternative source of air to the inlet manifold.

Fraser is correct, it is a vacuum servo for the fresh air scuttle ( Escotilla ) as found in older S type, 420, MK-X, 420G and Series 1 XJ.

Okay, but this valve is supposed to be in the engine bay?

Because when I took out the engine, and replaced it with AJ6, I only had 2 hoses coming out of the firewall. These hoses I connected to the correct hoses on the AJ6 engine that ran to the xj40 heater. It's the two hoses center left, in picture below (2 hoses on the right are from aircon, which had been disabled centuries ago)
https://lh3.googleusercontent.com/-3...o/DSC01780.JPG

The AJ6 has a heater valve mounted on the cilinder head. This is also vacuum controlled. This one is open without vacuum and closes when there is a vacuum (100% sure about this). I disconnected the vacuum on this on, so there is always hot water flow.

The reducer is heated by hoses that are running parallel to the heater. These hoses DO get hot, but the parallel hoses to the heater radiator don't.

So unless there is another valve, in the interior of the car, there somehow is now flow through the heater matrix. Could it be that somehow, the hot water prefers the reducer in stead of the heater?

I am having another thought.

Could I have nothing but air in my heater radiator? It seems to be the highest point of the coolant system, when I think about it.

If so, How do I get it out?

Is the last picture one of your car with the engine removed? I see the exhat down pipe off to the right.


If so, I see what appear to be heater hoses to the left. One should go through the fire wall and on to the heater matrix. the other should come from the other end of the matrix and back through the fire wall. Then, each of those should connect to the engine block. One as a supply of hot water and the other as a return. Now, we need a valve. More than likely on the supply line. My car is not the same, but similar. It has a vacuum controlled water valve. So, if similar in your car, that vacuum valve is controlled by a vacuum switch in the cabin.


So, think it out. Function first. How is it done next. Then seek out the components.
The, seek out what isn't doing the job!! No vacuum? Leaking lines. Bad valve?


With the engine warm, although if the engine is out, you can't do this, see if one or both hoses are hot??


And, lastly, a poor thermostat, not allowing engine temps to get up means poor if any heater performance!!


Ponder the thing.


I'm messing with a Briggs and Stratton powered lawn vacuum. The engine seems healthy, but will not run. After a lot of 'stab in the dark' tune up tactics that didn't work, I began the ponder process. I think I have it. slight damage to the "kill switch" !!!! . It is on "kill all the time. Fixed the switch. Now to put the thing all together again!!! .


Carl

Yes, the pic is with enginge out. But that pic was made long time ago. Now there is an AJ6 engine in there.

There is NO valve, I threw it out. Because the AJ6 engine has the valve attached to the cilinder head. I didn't want two valves doing the same job. The valve on the cilinder head, however, is always open as this is required for the LPG reducer to get warm.

Anyway, for the moment I am thinking it must be air in the system, and I will make sure the air is out first. Then see what happens. Will get back to you.

So, heater always on?


Try the hot hose, cooler hose idea.


just cause the A6 valve is there, doesn't mean it is working.


Your gas system may be just living with sorta warm.


An IFR temp guage would be fun to use to diagnose.


Still messing with B & S controls. someone before me has messed with them. I got the "kill" switch feature figured out and it should perform as commanded.


The choke feature is inoperative. M ore PO messing??


Shoulders tired. It is on the ground, and I function best at waist height!!!
The year thing, 85 of them!!!


I did use the power sweeper to do the patio garage and drive. Better than a puch broom, but it takes a toll on shoulders.


Mine isn't the pro quality of LnrB's!!!


Carl
Carl
Carl


Carl

well, thanks for trying to help me out. But a little reading would save a lot of words probably...? (no offense)

So, that was me saying Twice that I am sure the valve on the cilinder head is open. And then comes this response...

Anyway. The heater issue is fixed. there was air in the system, and the hose to the heater radiator was bend too much, so no water could pass. As the hose was tucked away between the engine and firewall, this could not be seen on first sight. Now, there is a nice flow of hot air coming into the car! Lovely

As for this:

I have no idea what you are trying to say here...?

Don' sweat it. Merely an unrelated side bar comment.


Glad you fixed he heater.


Carl