Loosing coolant

[woody95]

Hi I’ve been loosing coolant pretty rapidly the past few day’s I can’t see any leaks I’ve changed the expansion tank cap and no difference I’ve changed the oil and it wasn’t milky at all if I put my foot down to about 90 the temp will start to creep up any ideas? Head gasket maybe? I’ve had The garage test the head for leaks twice and there wasn’t any but it seems like I’ve got back pressure in the coolant system.

[Magnet]

Hello Ryan,

Petrol or diesel? Mileage? How much coolant is it using in say 100 miles? 

Possible head gasket? Often generally considered as being the offender, but.....

No emulsion in oil does not exclude that possibility, since the gasket can go between the cylinder and a waterway and the majority of coolant is expelled out through the exhaust. 

Simple check:- Take the car for at least a 5 mile run to ensure coolant, oil and exhaust are all hot, then rev. to 2000rpm and hold steady at that rev. for at least 2 minutes, while observing whether there is any excessive (white) smoke from the exhaust. 

Dependent on all above, it should be possible to move on with other tests.

Kind regards,

Gareth. 

[woody95]

3 hours ago, Magnet said:

Hello Ryan,

Petrol or diesel? Mileage? How much coolant is it using in say 100 miles? 

Possible head gasket? Often generally considered as being the offender, but.....

No emulsion in oil does not exclude that possibility, since the gasket can go between the cylinder and a waterway and the majority of coolant is expelled out through the exhaust. 

Simple check:- Take the car for at least a 5 mile run to ensure coolant, oil and exhaust are all hot, then rev. to 2000rpm and hold steady at that rev. for at least 2 minutes, while observing whether there is any excessive (white) smoke from the exhaust. 

Dependent on all above, it should be possible to move on with other tests.

Kind regards,

Gareth. 

It’s a diesel on 170k over 100 miles it would go from the max mark down to almost nothing at all I’ve had to fill it up twice completely over the weekend after doing about 300 miles. I’ll do what you suggested and get back to you after work tonight thanks for the quick response. 

[Magnet]

Thanks Ryan.

[woody95]

On 1/27/2020 at 11:04 AM, Magnet said:

Hello Ryan,

Petrol or diesel? Mileage? How much coolant is it using in say 100 miles? 

Possible head gasket? Often generally considered as being the offender, but.....

No emulsion in oil does not exclude that possibility, since the gasket can go between the cylinder and a waterway and the majority of coolant is expelled out through the exhaust. 

Simple check:- Take the car for at least a 5 mile run to ensure coolant, oil and exhaust are all hot, then rev. to 2000rpm and hold steady at that rev. for at least 2 minutes, while observing whether there is any excessive (white) smoke from the exhaust. 

Dependent on all above, it should be possible to move on with other tests.

Kind regards,

Gareth. 

It’s a diesel on 170k over 100 miles it would go from the max mark down to almost nothing at all I’ve had to fill it up twice completely over the weekend after doing about 300 miles. I’ll do what you suggested and get back to you after work tonight thanks for the quick response. 
 

 

hi I’ve done what you said and there was no excessive white smoke something I did notice though is when I put my foot down the heater starts blowing cold till I back off a little bit if that helps at all. 

[Magnet]

Hello Ryan,

If this were mine, my next move would be to get the coolant system pressure tested to see if it’s over pressurising. 

Kind regards, 

Gareth. 

[Zsolt]

Hy 

I am experiencing the same problem with my 1.9tdi, 130hp. I am losing water through the overflow of the expansion tank. 

Have been at 2 garages and changed the thermostat, water pump and the expansion tank. Have made a pressure test, head gasket test and put in some blocking fluid and nothing happened. 

Hope you can help me 😁