coolant loss

[shorty]

Every 2 to 3 months my car will display a message asking for the coolant to be topped up . I have checked the car for leaks or signs of leakage and cannot find any . I have changed the rad , it was a valeo and the cars a 211 of 2003 vintage , and thermostat . I suspected the water pump but I have instected this with the car running and at full operating temp and could see no traces of coolant .
I was gonna one of the rad weld products to see if this cures the leak as I cannot find it and im now thinking its the heater matrix .
Any other suggestions , is this a bad idea to use a rad weld product .

 

[misfire84]

it the car actually using coolant ? if not are you getting the screen wash level alarm going off also .. I had this problem and it was the sensor as both use the same pair of wires and if any one goes down it triggers both alarms off.

 

[shorty]

Its deffo loosing coolant .
When I get the message to top up coolant I need to add about 1 litre to fill the header tank up to the max mark

 

[Dieselman]

Perform a combustion gas in coolant test, either with a 4 gas analyser or a Block test kit.

 

[shorty]

Would I not have over heating issues if the HG was failing ?

 

[BlackC55]

Not necessarily.

 

[shorty]

I get a sniff test performed on the coolant .

Thanks for the replys Lads

 

[grober]

Other possibility is a defective pressure cap on the expansion vessel allowing water to escape via the overflow pipe? CHG does seem to be a likely candidate tho. Sometimes an inspection of the spark plugs or the tops of the pistons via a torch shone down the spark plug holes will reveal something. Best done after the car has been sitting overnight as water gets pulled into cylinder/s as the engine cools. The top of the piston may look black and "oily"= wet on one or more cylinders.

 

[shorty]

I changed the plugs on the cars last service , and the old plugs where a healty brown colour , none where wet or sooty .
I have a pressure cap ordered , and im getting my indy to do a sniff test to hopfuly rule out the HG

 

[Smiley]

Dont put any radweld (take a look at k-seal rather than radweld if you end up considering that solution) in until you have a good diagnosis. If the sniff test is negative then pressurise the system - if it is the water pump you will see it leak straight away.