Have searched the forums a lot and taken the car to 2 garages so far, current diagnosis is head gaskett or cracked cylinder head. I'm pretty much ready to cut my losses and hassle and sell the car as is. However, as I might have access to a driveway over Xmas I could do some final checks myself......so would appreciate any expert advice or experience on:
> Is there a way to distinguish between head gaskett vs cracked cylinder head. I understand the 115bhp engines can be more susceptible to cracked heads vs older 110bhp engines.
> What's a likely cost for head gaskett replacement, I'm reckoning about £1k?
> Is a blocked radiator or heater matrix likely to be causing the problems? I could probably do these jobs myself over Xmas
- losing coolant for several months, slowly getting worse. Currently losing 2 litres every 200 miles. ALL coolant loss is through coolant tank expansion pipe (I built a catch tank so can measure this exactly).
- VAG specialist carried out block test (=compression test?), no loss of compression.
- Poor circulation found, water pump removed and tested - all OK. System flushed through and circulation (supposedly) improved. However coolant loss continued.
- Coolant loss MUCH worse when car is under load (3000rpm +). Also appears to be worse at motorway speeds (70 mph +)
- No coolant loss when car is coming up to temperature (up to 90degC on dial), heater works fine at this point. When the car reaches 90ish, heater starts to cool and takes a while to get hot again.
- Car sits at 90degC almost all the time. Occasionally (when pushing on) temperature will suddenly shoot up to 110-115, if you back off it then slowly comes down (I've not kept going to find out what happens!)
- Temp readings on dial are the same as the electronic temp reading (channel 49 on climate control)
- Coolant loss feels erratic, some journeys (slow, no motorways) are fine, others then lose lots of water!