Hello,

I am seeking any wisdom of what to try next before handing over £££ to the main dealer.

I have a second edition 2015 2l 180bhp mk5, which I've had from very nearly new (it was the demonstrator) with 110k on the clock.

Driving home last weekend it suddenly displayed the temperature warning and the needle rose rapidly into the red with the fan blowing and coolant bubbling. I stopped immediately and let things cool. It then did the same thing twice in the space of 3 miles, so I got it recovered by the RAC.

I am not losing fluid and a scan of the codes showed an engine temp warning, P26A6-21 and -37 logged. These last two relate to the engine coolant bypass valve sensor signal level and frequency respectively.

I have replaced the thermostat housing with an new OE part and cleared the codes.

The car runs OK (no smoke from the exhaust or steam under the bonnet), will get to temperature (though the needle does show drops in temperature before climbing again), hold temperature at 80deg and then all of a sudden rocket into the red. The top radiator hose is warm, the bottom hose cold and I am getting heat into the cabin.

In the likelihood of what to try next is the water pump my next culprit, even though there doesn't appear to be any strange noise from that part of the engine? Is there anything else I should be considering?

Can the electronic thermostat and water pump be tested somehow via the ODB port?

Thank you for reading.

Gavin

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'65 2015- 2l Titanium 180bhp 110,000miles

Hi. Just had a similar problem. What was the outcome of this issue in the end? 

1 hour ago, Martin Cole said:

What was the outcome of this issue in the end? 

Who knows ?

@GavinC hasn't been back to the forum since 27th April