Why does my 75 Turbo Petrol Estate Lose water
 

Hi Guys..help need please...I seem to be topping my car up with water at least every other day about 3 cups full. I can t see any leaks around the hoses that are visible. I have had a compression check all ok..last week new inlet gasket fitted.

I top up to where you can see the vents inside the radiator but the water drops well below that when I check in the mornings..

I have the right filler cap on.

What I want to know is the heater system connected to the engine cooling system..could I be losing water in there somehow. There is no water left on my drive.

any ideas

Thanks

Bill

Bill, just to go over the filling procedure, the "MAX" level is very very low in the expansion tank, almost on the bottom; do you get ejected residue around the expansion tank cap after a run? it could be, if you do, that the system is doing what it's meant to do, by reducing the content to the correct level.

You may have had a new inlet gasket fitted, however if the bronze coloured ferrules contained within the manifold have moved slightly with over zealous tightening due to poor gasket squeeze or manifold distortion the gasket will not be compressed sufficiently.
https://the75andztclub.co.uk/forum/s...03&postcount=1

Or alternatively fit a VVC manifold ;)


On the heater question. Yes it is possible to leak from there, but perhaps you would get a faint whiff of coolant smell when using the car, or windows would steam up easily. Remove the little triangular shapes in the footwell around the centre console and have a look in there for any leaks and coolant staining, powder.


Other suggestions:
1. Water pump can leak without showing dripping coolant as there maybe an evaporation chamber incorporated in the pump itself. Have a look under the front and timing belt area in sump of the engine as dried coolant residue can form usually pink powdery look.
2. Radiator.
3. Thermostat housing (or empty thermostat housing if PRT fitted) at the back of engine underneath inlet manifold can distort. The single O-rings philosophy can leak if they get flattened over the years and are fitted with silicone grease (or other sort) or even twisted if too dry on fitting.
4. Radiator cap O-rings.
5. Steel coolant pipe that runs around the back of the engine to the thermostat housing can corrode in micro spots and leak?
6. All other pipe hose connections that have plastic and where someone has replaced with a jubilee clip distorting and compressing the plastic fitting.
7. T-piece (if fitted) at top front of radiator the swaged on clips can cut into the hose and cause leaks, the owner fits jubilee clips and actually makes it worse in long run.

water leak
 

Hi Can you confirm the water level on cold start...

When I take the cap off I cant see any water or its below the fins inside the radiator...are you saying it should be as low as this.....If thats the case what I am doing is filing it up to top of the fins about 10 mm from the top..Then as you say it expands off....

could someone take a picture for me from there car looking down into the radiator how low the water should be from cold or some manual I can read or see.

Thanks

Its the header tank you should be looking in I think?

I am slightly confused, the cap is on the expansion bottle, you refer to radiator, . The upper & lower coolant limits are marked on the outside of the expansion bottle and are fairly low down when engine cold. Where is the level relative to these when cold?

Ignore the coolant level sensor fitted in my tank as yours wont have that but you can see the MIN and MAX levels in both photos. The photo with the coolant level is at the MIN level which is well below the fins. Top of tank removed during experimentation of sensor fit.

Actually if you remove the cap and shine a torch inside and view at the right hand end of the coolant tank near the two mounting spigots there are min and max marker levels there too which you can only see fluid level with a torch. The original design was intended to have a coolant level sensor but never made production, hence the tanks are made of material that you cant really see through.

https://preview.ibb.co/irBLDo/12_Job_done.jpg
https://preview.ibb.co/cLADYo/IMG_0681.jpg
https://preview.ibb.co/gz8iYo/End_Elev.jpg

water level.
 

OK I think we are getting there....My car has now stood for 4 hours I have taken the header tank cap off and the water level is down 35 mm from the top.so its about bottom of the fins...what I would do now is top it up a bit so the fins dont show.....but that is where I could be going wrong.

would you agree the water level should be as low as this for normal use. 35mm aprox down.

Thanks

Bill

From the top of the coolant tank (NOT THE FILLER NECK) at the MAX mark the distance should be 59mm, see here for early black tank dimensions which will be the same as beige tank. Again ignore the sensor reference, just focus on MIN and MAX marks and the dimensions. Looks like you are filling it up too much.

https://preview.ibb.co/c1uFUT/Schema...Black_Tank.jpg

Just popped back in; I would suggest that you extract (whilst cold) an amount of the coolant until you actually see the MAX marking, it really is very very low in the expansion tank (one cannot actually see into the radiator). You cannot harm anything by taking out as you can then add some of the removed coolant until you are just covering the MAX marking so as to still see it. It could be described as the marking being on the bottom, so extract some until you see it. This is, as it states, the maximum level, and the system will compensate during the expansion caused by heat and then the cooling should bring it back to the level. Do not open the expansion tank whilst the fluid is warm as that is dodgy and will give you a false reading.