Hi all,

I raised a thread some time ago about no heat from my Yeti. Unfortunately I didn't get any response. 2016 2.0 TD 110BHP. I thought it might be a temperature sensor or one of the flaps stuck, so got a VCDS and no faults were found. Well there was one, think it was air quality sensor that turns the air circulation to internal when the air outside is a bit dodgy. Not done anything about that. It has climatic control and with the temperature dial set to max you still get not heat out. I pulled a bit of trim in the passenger footwell and can see the pipes going to the heater matrix. With the car warmed out, temp gauge showing 90, these pipes remain cold. I performed the two stage air bleed of the coolant system with VCDS. No improvement. The heater pipe in the engine bay has a small pipe that goes back the filler bottle, so it looks like it should self bleed anyway? I think I read somewhere that the heater matrix is in series with the EGR cooler, I could be wrong. So is it a blocked matrix, an air lock or a blocked water pipe in the EGR value? Is a vacuum fill of the coolant system required?

Your Yeti will have an auxiliary electric coolant circulating pump as well as the mechanically driven one. It's possible you have a problem with this which is affecting circulation. As you surmise, the cold hoses suggest either an air lock or some other failure to circulate coolant through the heater matrix.

This discussion might shed some light: https://www.yetiownersclub.co.uk/threads/coolant-pump-2.10954/

I suspect that vacuum filling is used at a workshop because it is quick and thorough. I recently refilled my petrol Yeti without vacuum, just let it run for half an hour and kept topping up as required. Another top up was required the next day after cooling, unacceptable for a clean handed "chequebook" customer but fine by me. So I suspect the system is designed to (eventually) self bleed.

With sealed systems and effective inhibitors, engine cooling internals stay remarkably clean so blockages should be a thing of the past.

4 hours ago, Austin 7 said:

Your Yeti will have an auxiliary electric coolant circulating pump as well as the mechanically driven one. It's possible you have a problem with this which is affecting circulation. As you surmise, the cold hoses suggest either an air lock or some other failure to circulate coolant through the heater matrix.

This discussion might shed some light: https://www.yetiownersclub.co.uk/threads/coolant-pump-2.10954/

I suspect that vacuum filling is used at a workshop because it is quick and thorough. I recently refilled my petrol Yeti without vacuum, just let it run for half an hour and kept topping up as required. Another top up was required the next day after cooling, unacceptable for a clean handed "chequebook" customer but fine by me. So I suspect the system is designed to (eventually) self bleed.

With sealed systems and effective inhibitors, engine cooling internals stay remarkably clean so blockages should be a thing of the past.

Thanks for the response. Wouldn't the auxiliary pump failure be picked by VCDS?