740 1988 Water, Rad, Pump Cooling system

[Rock]

I thought I had a problem with the head gasket on my 1988 740.

There was a strong smell in the water header reservoir which I now think may
be from changing the water pump, plenty of sealant was used on the water
pump so its possibly the sealant I can smell in the water.

Have just taken the car for a run of 50 miles and have lost no water from
the radiator, if the head gasket was gone should I not be losing water.

There is at time what appears to be quite a high pressure in the water hoses
but this I assume could be caused by the cap on the water res playing up.

If I leave the car overnight when I take the header cap of the reservoir
when the car is cold there is still pressure in the system so this would
again I hope indicate that the head gasket is not gone or there would be no
pressure.

 

[Peter K L Milnes]

You could have a sticking valve in the radiator cap possibly caused by an
emulsion of sealant and coolant. Clean the cap thoroughly inside or replace
with the correct pressure value cap.

Cheers, Peter.

 

[Rock]

What pressure should the engine be at.

You could have a sticking valve in the radiator cap possibly caused by an
emulsion of sealant and coolant. Clean the cap thoroughly inside or replace
with the correct pressure value cap.

Cheers, Peter.