You haven’t said whether your enquiry is because you own the vehicle and need to know what is wrong, or if it is simply because as a driver you’re just interested. If it is the latter then it is someone else’s problem to sort it, however you need to make sure that they understand that thee is a potentially serious problem with the vehicle.
If it is your own vehicle then do as the first respondent advised and have a Co2 test done; carried out correctly this will indicate whether there is a head gasket problem or not. All the other suggestions you have been given are possibilities, but the issue needs investigating as a matter of urgency in a logical and methodical manner because if this is not done then this will develop into head gasket failure at the very least.
hanson:
Seen similar before remove radiator and jet wash behind it you will be suprised how much rubbish gathers in between rad and engine?
One warning do not jet wash the radiator directly, as the pressure can damage the radiator .
mm1988:
I drive an r420 and last week I had exactly the same problem. It got worse and worse over the week until I was stopping every 45 mins to refill the water and they had to get me straight back to the yard. The problem was a blown gasket on the air compressor
There is a subbie that runs a V8 that pulls trailers from our place. I came in one morning to find the driver filling it up with water. That was the 5th time she had done it that night.
Radar19:
mm1988:
I drive an r420 and last week I had exactly the same problem. It got worse and worse over the week until I was stopping every 45 mins to refill the water and they had to get me straight back to the yard. The problem was a blown gasket on the air compressorThere is a subbie that runs a V8 that pulls trailers from our place. I came in one morning to find the driver filling it up with water. That was the 5th time she had done it that night.
Yes but how many times did she have to top the radiator up ?
old 67:
Radar19:
mm1988:
I drive an r420 and last week I had exactly the same problem. It got worse and worse over the week until I was stopping every 45 mins to refill the water and they had to get me straight back to the yard. The problem was a blown gasket on the air compressorThere is a subbie that runs a V8 that pulls trailers from our place. I came in one morning to find the driver filling it up with water. That was the 5th time she had done it that night.
Yes but how many times did she have to top the radiator up ?
Why am I detecting a ulterior motive here?
This is an old post but more than likely the headgasket on the compressor is on the way out and its building air pressure in the coolant system,