On mY 2012 xc70 with 3.2 L recently was about to ge my serpentine belt replaced but just before I drove into a oil change service shop- drove into the raised ramp then I got a lot coolant warning light, checked engine - reservoir was just a tad under full, left shop then drove 1/2 mile and got a -- engine temp high reduce speed see manual- warning light, so I stopped, shut off car and waited. then drove after 5 minutes to a very close import repair shop where again 1/2 mile later engine high temp light ( mind you driving 20 mph ) so a couple hundred feet later was at door of shop to get work repair..Question; if a small amount of coolant leaked out near the front wheel well -does that mean a bad hose, clamp, or worse like a head gasket?

 

if your coolant reservoir has anything in it you wouldn't get a high temp light. sounds like having no belt to drive the water pump would cause the overheat. On most volvos the reservoir cap also serves as a pressure release valve - so an over heat would likely blow off the reservoir top which would push coolant everywhere. Its possible also that an overhead can cause a head gasket issue (heat warps the head). That's a common outcome on the I5s, not sure about the 6s. I'd have the belt reinstalled as well as a new thermostat and then check for leaks and test for a head gasket fail.

 

thx for reply, I did get the serpentine belt replaced, the tensioner broke down so belt was slipping/not driving pump as you suspected, shop said that after replacing belt they pressure tested and found no leaking coolant, BUT that they can't guaranty that nothing will happen, saying the head gasket may have been damaged...so what
I want to mention is that when the " engine temp high reduce speed see manual " dash light came on I was only driving 20-30 mph, then stopped immediately, and shut off engine, then drove to shop after at 20 mph for about mile tops , I am hoping that immediate reaction to the warning light, then a slow short drive to shop( thank God )
was good to prevent real gasket damage ?