“In this video I replaced the heater core in a Volvo S70. It is almost the same in the 850 other than the way you remove the lower dash panels.”
When you need to perform a heater core replacement, it’s usually the result of poor cooling system maintenance. Flushing and replacing your coolant as a part of regular Volvo maintenance can go a long way toward preventing issues caused by the buildup of rust particles, dirt and depleted anti-corrosion ingredients in the fluid. Your heater core’s narrower passages are especially susceptible to failing because of this gunk.
There are several telltale signs that you’re experiencing a heater core problem:
- You have little or no heat inside your car
Your vehicle is running fine, with the temperature gauge reading normal and no other cooling system problems. But when you turn on the heat, it never warms up.
2. You smell coolant inside your vehicle
As you drive, you can detect the sweet, fruity smell of coolant inside.
Your windows fog up
This is a more extreme version of the coolant smell scenario. The amount of coolant spraying out of the heater core is enough to form a mist that coats your windows and is difficult to wash off.
You see signs of a coolant leak under the dashboard
You may notice coolant dripping down from under the dashboard, or there may already be a big, damp coolant stain on your front carpeting.
Your coolant level is dropping, or your engine is running hot
If you have a leak anywhere in the cooling system, including the heater core, it’ll cause a couple related problems. Your car will lose a significant amount of coolant, and eventually your temperature gauge will run higher than normal.