polo 1.2 AWY O2 sensor 2 P0036 code

[Rob69]

Is it not just the radiator working well enough with an idling engine without the fan in the current low ambient temperatures, preventing the coolant at the fan sensor (located at the cool bottom of the rad) getting hot enough to switch it on ? If your heater is working ok and the engine is not overheating while driving then i'd think the WP is ok. Can you drive it hard up a long steep hill to get sustained high load on the engine, then pull over at the top and have a look and feel at the hoses. Even consider blanking the rad with cardboard during this test to prevent air flow, but being carefull not to cook it!. Have you got an OBD tool you can plug in to get a better idea of coolant temp at the CTS. I've recently had overcooling issue on my passat and used vcds and a obd scanner to get better temp indication than the dashboard temp gauge.

[shep73]

Thats a good point, will try that on the run home from work tomorrow. My local indie commented that the car was overheating when doing the emissions testing for its last MOT, but since it only ever does short journeys I've never really bothered to look into it until now.

Thanks for the advice guys

Brian

[Crasher]

The reading on all modern VAG cars temperature gauges is meaningless, dangerously so. It reads 90 at a real 77 and still reads 90 at a real 117!

[Rob69]

Exactly, I think even a lot of basic OBDII diagnostic tools can give a CTS readout to get a better idea of true temperature.

The reading on all modern VAG cars temperature gauges is meaningless, dangerously so. It reads 90 at a real 77 and still reads 90 at a real 117!

[shep73]

gave it a good thrashing on the way home ! nice and warm by the time I'd made it up the bigger of two hills. Thermostat housing and lower radiator hose stone cold !!!
Pretty sure its still a thermostat problem. Going to pull the new one off and check it opens properly