I recently took a drive and when I got back home I popped the hood. I felt both the hoses and both were very warm, I thought the one was suppose to be cool? Temp gauge on the dash never hits the green zone or middle and stays a notch below around 85. Any ideas what it could be. The heat on full blast at 85 blows out warm and not as hot as it should be. Xj6 series 3 1982. Coolant is always at the right level.

 

Both radiator hoses will be hot to the touch after the engine is fully warmed.....even if the coolant gets to 'only' 85ºC

Normal.

Cheers
DD

 

Ok thanks Doug, Just curious does your series 3 crank slow in the morning when in cold weather?

 

On the upside, your radiator is working and the engine is warming up. Just not hot (on the inside).

I have a Jaguar service manual for the Series III. Better than nothing.

I am thinking that you have one of two things that can be causing your lack of heat.

1. Your air blend door is binding/stuck. You may be stuck in "summer mode" and the venting is configured for cooling you down - not heating you up.

2. The valve that allows (hot) coolant to enter the cabin is not functioning properly.

I'll make a deal with you. If you keep all your posts regarding your heater not working to this thread, I'll help you as best I can.

I will PM you my phone number if you wish. I'll even drive my fat *** to T-town to help you out if we get it narrowed down. I have family there and that would be a good reason to visit the sorry *******s.

I do have a 77 Jag here (Akron) that I can use to help you verify if things are working on your car. They cannot be that different as new cars still work the same.

Keep your posts here so the real Jag nuts can follow it more easily.

 

Haha you got a deal, so far the car has been running good with no problems for a month. The only things I can think of on the top of my head with this car is the temp gauge, I also have a problem with the changeover system. I put gas in both tanks and one becomes more full then the other. I use the left tank only now and its been working every time. Cruise control doesn't work but all the windows do. Battery light stays on but voltage is always good. That would be awesome if you were in Toledo one day and you could check it out

 

Thermostat for 195 Fahrenheit just came in the mail, gonna change it for the hell of it and see if that helps anything.

 

The 77 I have has been "tweaked" with several check valves and better plumbing in the trunk bay. It works well but the fuel gauges are toast. They lie. They lie like a rug.

Here are the new gauges I bought from John's Cars (pic). Way less than I expected $$ wise. Maybe your issue on the fuel level? I don't think the 77 passes fuel between the tanks. I am certain it's just one tank at a time it pulls from and then the same tank gets the return gas that is not used.

 

Here is Jezebel airborn.

 

Good info on cruise control and changeover systems

Cruise Control

Fuel Tank Switchover Checklist, Series III XJ6

Cheers
DD

 

The heater valves are the usual bad suspects!
They can fill up with crud and cause flow restriction.
They were generally crappy quality.

 

Thanks for the info on the valves. I don't have much experience with Jags in general.

If it were the valves, they are on the engine side of the firewall, correct?

Has to be easier than getting to the air flapper door under the dash.

 

My 1975 coupe's heater valve is on the outside of the firewall.