Good afternoon,

I have a 2015 XC60 T5 and I'm having the following problems:

1) The car will apparently overheat unexpectedly and rapidly. The temperature gauge will go up and a message will be displayed that says the engine temperature is too high reduce speed or engine temperature is too high stop safely. The radiator doesn't feel excessively hot nor does the coolant tank (on the left side of the engine compartment)
2) The heater will not blow hot air ever. Very often the air is cold even when both temperature settings are on HI.
3) Sometimes the large top radiator hose running too the thermostat does not feel like any coolant is being pumped through it when the engine is hot. The small hose that bypasses the thermostat always feels like coolant is being pumped through it.
4) The heater hoses don't feel like any coolant is being pumped through them.

I'm looking for people with similar experiences and would like to know how you resolved the problem. I suspect the thermostat and I've bought the part. I haven't installed it because as it turns out there are a few things in the way that have to be removed before the thermostat can be replaced. I don't want to spend several hours replacing a part that isn't bad if I can help it.

I've seen one youtube video of a guy that replaced his thermostat and the old one came out in several pieces. How to Replace the Thermostat on a First Generation Volvo XC60 and XC90 with 3.0T and 3.2L Engine ? How to Automotive

 

It really sounds like the thermostat has gone t*ts Up.. that is the one item that will keep the hoses cold and make your wallet ache...

 

If you never boiled over, you may have a failed water pump. pop off the timing belt cover to see if there's any weeping - no heat means no circulation and I don't think the thermostat gets in the way of the coolant to the heater core... If you did have a boil over and lose coolant, you should replace the thermostat and the overflow reservoir cap, inspect the hoses and radiator seams etc. Finally if you refilled to coolant, you may have air trapped in the system which can impede circulation to the heater core. Your model may have a bleed screw to help get any trapped air out.

 

I have not had the opportunity to dig into this yet and see what is wrong. I agree that the two most likely culprits are the thermostat and the water pump. From the looks of things under the hood both will be difficult to get to so I am going to have a look at the thermostat first.

 

OK. This will be the last update. It was the thermostat. I had it replaced and everything is OK. I talked to my mechanic, he has been working on Volvos for years, and he told me he has yet to see a water pump go out on this particular car. The guidance on the timing belt is to replace it at 95,000 miles so that's what I'm going to do.

 

​​​​​​I am having the same issue. When it happen the engine temp goes up very quickly and no heat comes out of the heater vents when they are cranked full blast. Then heat starts blowing out of vents and engine temp drops like a rock. The sucky thing is that we already changed the thermostat figuring that was the issue. I guess the new Volvo thermostat might be defective.