XC60 D5 2010 Cooling System Service Required
 

A few weeks ago, my alternator belt broke. I decided to ask my local garage to replace the timing belt and water pump whilst changing the alternator belt.
After it was fixed, I noticed that the car heater was not giving out much heat.
Suspecting an air bubble in the water system, I asked the garage to check it. They didn't find anything wrong.
After a longer journey, with still negligible heat from the heater, the Cooling System Service message was displayed.
The garage checked it again and reset the ecu to clear the message.
I still have negligible heat. There are no leaks.
I suspect the new water pump may be faulty and not circulating the water properly. But are there any other possible causes for this? Is there a special way to refill the water to get rid of air in the system?
Before the belt broke, it was all working fine.
Hopefully someone will be able to help.

What kind of cooling alarm? temperature high or low coolant level?
It could be that there is some air trapped.... normally it takes a little while to get all the air out of the system after a repair.
But that should only be a little bit of air.

Check if the hoses to the radiator get warm after warmed up, if so the pump should be ok.
Also before shutting the engine off unscrew the expansion vessel cap (carefully and just enough to let the pressure out)
screw it tight again and the cooling of the engine will shrink the air bubbles in the engine and pull more coolant in....
Rinse and repeat
Or use a brake bleeder on a cold engine on the expansion vessel to create some underpressure to gget the same effect

Thanks 5cilinder for the reply. The message doesn't state if it is high or low temperature. Just service required. It happend on a 25 mile journey, so probably hot.
The message continued to be displayed even when the engine was cold again, and fans on all the time until the ecu was reset.
I normally only drive short distances, so I suspect when I drive further, the message will return. I will do some checks of the pipes as you suggest.

Check both coolant pipes at the back of the engine bay going into the car.
They are constant flow, providing the hot coolant for the heater matrix in the cabin.
Both pipes should be equally too hot to hold when the car is up to temperature.

Why not look at the expansionvessel first? after alarms like that? maybe you need a topup after an airbubble was freed or/and monitoring your tempgauge.

Also check the tempsensor connection if that is disconnected the engine"thinks"
its "hot"
Make sure indeed that those coolanthoses going into the car are hot like beardaddy said , they should be because they are full flow in the engine circuit
If they are, your pump is ok but maybe there is still some air trapped in the heater but the combination of the coolant alarm its is more than that

As said in the post above the coolant expansion tank is likely where the message is coming from.

I would also ‘YouTube’ how to bleed the system. There is usually a bleed valve at the top of the radiator isn’t there?

I would also suspect thermostat. If the thermostat fails, and they often do then that would give you the symptoms you have, no air, slow to hear up etc etc.

Fortunately if it is the thermostat that should be a low cost fix.

It should have self bled by now especially after a longer journey.

Don't these models have an auxiliary electric heater core along with the traditional water heater core for quicker cabin heating? When the auxiliary belt snapped it would have knocked out the alternator, therefore no charge nor voltage regulation available so check to see if the fuse for electric heater blew at the same time.

Bleeding can take a long time with this engine

I can't speak for this vehicle but in the past when I've encountered a difficult to bleed vehicle, I've had success by elevating the header tank by either unbolting it and letting it up or Jacking the vehicle up at the corner it is attached to, making it higher than the rest of the water circuit. Air is then encouraged to rise to the highest point, i.e. the header tank.

This practice was the only way for some Renaults back in the day. In fact it was the factory cure for the Renault 5's by hanging the header bottle two foot up in the air off the bonnet.

True there are a lot of tricks.... but sometimes there are high points in the engine followed by lower paths where air gets trapped.
Some engines have bleedscrews in strategic places
Extreme fluctuation in the expansion tank is a symptom because heated air and cooled does its work