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I have a normal temperature gauge sometimes lower than normal, when i turn off the engine coolant is forced out of the header tank. There is a blocked small pipe that is situated in the middle of the injectors would this be anything to do with the problem
My car's temperature gauge normally runs about halfway between Cold and Normal. Will creep up to N in very heavy, stop-start traffic or hard driving up steep gradients. I know many people criticise the old fashioned gauges but I find them very responsive. On a run along a road with up and down gradients I see the gauge move slightly accordingly.
So, to your issue.....
What do you mean by "coolant is forced out of the header tank"? Is coolant forced out of the filler cap or does the level of coolant in the header tank go down when (after cooling) you remove the cap? If the former it sounds serious, if the latter see below....
What should happen is, as the coolant heats up and expands it is forced out of the header tank into an overflow tank at the back of the offside front wing (not sure if this switches to the nearside wing for LHD cars). As the engine (and coolant) cools the reverse happens (via vacuum) to keep the coolant level in the header tank just below the level of the filler cap. The pressure cap on the header tank is very clever in allowing this two way flow. I had a problem with mine in that it was allowing flow out of the header tank but not back the other way so my expansion tank level was always low. A new cap fixed this.
It is a very sensitive system. I disconnected the overflow tank to do some bodywork and water would flow out of the expansion tank just due to ambient temperature variation through a hot summer day.
Not sure what bearing your blocked injector valve has on all this.
Yes there is a bottle inside the off side wing which wasn't connected to the header so i just have the forced out water going down a pipe to the floor, i fitted a new 16 psi cap, so all i need to do is connect the expansion, I noticed a few times when i disconnected the small injector valve pipe i could hear the tank cap drawing air back in to the system. I can understand whats happening now thank you for the detailed explanation.
The pipe from the thermostat to the injector valve is OK but the out pipe is blocked and cannot see where this connects to as its under the injectors, what is the purpose of the valve should i sort out the blockage?
My car is a RHD car been in France most of its life, i also need to replace the diff seal, but no one seems to want to take this on, my hands are not so good these days so need some one to help me
I bought a genuine Jag replacement header tank cap and that is marked 16 psi so it looks like you now have the correct one.
Key thing is that the end of the hose from the expansion tank has to be below the level of coolant in the overflow bottle. I think the advise is to fill the bottle about half full with coolant before inserting the overflow hose.
It is surprising how much coolant flows back and forth due to changes in ambient temperature without the car running. When I was treating corrosion in the inner wing area I forgot this and ended up with the whole area soaked in coolant after leaving the car on a very hot day. Had to scrounge one of my Father-in-Laws incontinence bags and rig up a bypass - see photo!
Not sure I understand where the blocked hose near the thermostat is located. Do you have a manual or parts catalogue that shows the overall hose layout which might help? Alternatively, when my car is next out of the garage I will have a look (nearside parked up against the wall at the moment).
Not sure where you are located in France but there are a few members on here who are based in France and they may be able to suggest suitable garages for the axle repair.
Hi Lee
So there is no pressure in the Tank and the hole on the side near the top of the tank is just an overflow vented to the outside, where it is situated there is no way of knowing whether its working, this is probably the reason i did not use it and vented the water to the ground not realizing how much water is forced out which needs to be sucked back to the header.
Jeff
Correct, there is no pressure in the overflow tank as it is open to atmosphere. Just need the end of the supply hose to be below coolant level so it can be siphoned back up to the expansion tank as the engine cools. The overflow tank has its own overflow via a narrow metal tube that exits near the inner edge of the sill although the pipe often rusts away.
The Tee on the link between Rad and Header tank split and is connected with a short piece of pipe with the pipe from the thermostat housing for the moment is blocked off until i find another pipe. That upper hose connected to the restrictor is the one that is blocked, i can see a metal pipe under the injectors which this must be connected too, difficult to find out exactly where. I have taken of the restrictor and one side is water and the other side is air and doesn't seem to be that important..
Having owned the car for 6 years and really like driving the car, they are slow to appreciate in value, a lot of car for a small price.
Thanks Lee for all the help
07-06-2023, 12:19 PM
