Hi,

I did search but couldn't find an answer, so here goes...

The head gasket failed on my 1.4MPI recently (using LOTS of coolant, loads of mayo on the oil cap etc). I replaced it and the job all went well, but now I have a few issues:

- The car gets to temperature quickly and stays there. It has never overheated

- It runs really well (no loss of power)

- Compression test on all 4 cylinders gives readings that are very close to each other

- No excessive steam from the exhaust

BUT...

- The top radiator hose seems to be getting a lot of pressure build up, although the pressure does seem to go away after a while

- It seems to still be using a bit of coolant

- The coolant warning light comes on a lot (the header tank and sensor are only a couple of months old). For example, today I checked the coolant with the engine cold and it was just about at the maximum level. Drove the car about 4 or 5 miles and the coolant light came on. Turned the engine off and back on again, the coolant light went out and stayed out. Finished the journey and checked the coolant level again, and it was just a little bit below MAX with the engine warm. Came out to the car after an hour or so, started it and the light immediately came on!

I'm worried there's still a problem with the head gasket, but I really hope it's just an airlock.

I've replaced the cap on the expansion tank and tomorrow I'll be changing the thermostat.

Anyone got any ideas? Is a pressurising top radiator hose normal? I would have thought that if it was a HG problem, the hose would pressurise and stay pressurised all the time the engine is running, but the pressure does seem to go away.

Cheers,

Steve

Pressure in top hose could be a thermostat problem. There is a little pin which allow water through to prevent pressurisation when the stat is closed. This can block. Once the stat opens the pressure in the top hose will drop. Sometimes people cut it off, especially on engines with a vertical thermostat. This problem can also lead to loss of coolant. If you're changing thermostat I'd suggest a good clean of the system as there may be bits left in there from the HG problem.

Hi,

Thanks for the reply. I dropped all the coolant out and renewed it when I changed the HG about a month ago and again today when I changed the thermostat (incidentally, I had to buy a whole new housing, thermostat and temp switch for £35 from Eurocarparts). I also very carefully bled the system to remove any air locks.

Anyway, that seems to have improved the pressure situation but as I was stood with the bonnet up, engine idling I heard the beep for the low coolant level. Leaving it running I looked at the expansion tank and the level was *only just* below MAX. So it seems the sensor is giving false readings now too! I think I'll just bypass it...

Thanks again

if anyone else is looking for a thermostat try gsf car parts they seem to be a lot cheaper on them