Air Lock or Head Gasket??

Hi all

I think I may have bought a dud, I’m having problem after problem with the 300tdi

After last weeks over heating problem I had someone replace the rad and stat for me as I didn’t have the time, they know a thing or 2 about landys so would have thought that the system was bled properly.
Anyway, all seemed fine after the rad change and I travelled 150 miles to Wales yesterday with no problems and with the temp staying just under half way.
Travelling around 1 mile into the first green lane I suddenly had no hot air from the heaters....temp stayed normal. So stopped, had a look under the bonnet and found water coming out of the header tank, took the cap off and the water was luke warm?!
Topped up and carried on going to a more convenient place to stop.
Still no heat out of heaters and water constantly coming out of the expansion tank but no change in temp.
Stopped again, took the rad and stat filling point bolts out, topped up with water through the rad (took quite a bit) then topped up through the stat housing then topped up through the expansion tank so I assume this would have bled the system properly??
Started on my way again and constantly having the same problem!
I did note that the water pipes were very hard while the engine was running, harder than other cars that iv owned?!
Tried the obvious hgf test, expansion cap off and rev the engine and no violent bubbles but as the engine heated up the water level rose until it crept over the top.......but the water in the expansion tank didn’t get warm!
I have no water in oil and oil in water etc etc.
All day I had no hot air from heaters.
Travelled home and started to get heat from the heaters, checked a couple of times at services and no water coming out of the expansion tank but quite a bit of pressure in the pipes, opened the cap to let the pressure out and no water escaped.
Temp stayed just under the half way mark all the way home


Sorry for the long post!!

hgf my guess

Any steam or water from the exhaust? Any mayo in the oil filler cap? Does sound like head gasket failure tbh.

Does sound like head gasket but check the little one way valve thing on the small return pipes (where the two small pipes go into 1 small pipe then to the expansion tank) mine failed once causing head gasket symptoms, i just replaced it and all back to normal

mine was exactly the same few month back, same symptoms, was the head gasket but first try filling with water from the bleed screw on top of the thermostat housing it may be airlocked but more likely hg

Taxed said:

Does sound like head gasket but check the little one way valve thing on the small return pipes (where the two small pipes go into 1 small pipe then to the expansion tank) mine failed once causing head gasket symptoms, i just replaced it and all back to normal

Click to expand...

I had mine fail at the glastonbury festival last year. I stuck a T-piece in as a temporary fix. They don't seem to like getting overheated. It seems that once this has happened thy start to play up.