Petrol engines Overheating

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Mocki: Symptons, overheating, emulsifying oil, overcooling

On the flat four WBX slight white gunge in filler is normal if you do short journeys in winter; aircooleds do it all the time. It's emulsified oil and the shape of the filler tube encourages condensation, and head gaskets on the WBX are not like inline engines, the oil and water rarely mix when they do go, most references to head gaskets "going" on these are really water jacket seals going, which result in air locks, which cause over heating, rather than oil and water mixing, and water dumping, or over pressuring, and chucking the water out of the top up bottle or blowing pipes off.

Keep an eye on the water level, in the header tank as well as the top up bottle, and the oil level, too, and most importantly the heater output, if it goes cold then hot then cold on your knee its airlocking, and the temp gauge may not show it, if it does it wont be at the same time as your knee feels it!

HarryMann: Petrol WBXs have a lot water pipes and hoses. A lot! Some are steel pipes in the engine bay and soem have steel pipes running the lenhth of the vehicle to the front radiator, running above the fuel tank on 2WD versions. These steel pipes will corrode eventually, so look for early signs, though usually from the inside out, often only found when doing other repairs.. e.g heads/water pump/thermostat etc.

VW Hoses are generally very good quality and can easily last 20 years or more.

Changing the anti-freeze at the prescribed intervals (about every 3 yeasr), using the correct type and ratio etc. goes a liomg way to maintaining your cooling system trouble free.

  • See Mocki's notes above on head seals and how to spot the problem in its early stages