Cooling system warning light
 

I have a cooling system warning light that has been on for quite a while. The coolant level is fine, and it doesn't seem to be leaking. Can someone give me some possible reasons this light could be on?

Easiest answer, and therefore probably not the right one, is stuck/inoperative
thermostat. It may not be fully opening, and therefore causing the coolant in
the block to overheat. Maybe a worn out water pump which would cause the
same symptom. Possibly a bad sensor for the light, too, causing misreading when the system itself is working just fine. I don't know what Volvo thermostats and sensors for coolant temp cost. Sorry.

If the coolant level is fine, then it is unlikely that the light is caused by overheating. If the light is on when you start the car, your coolant level sensor is probably either bad, or the contacts are dirty.

What I would do is remove the cap (when the car is cold, of course) and see if I can move the float. I think that it is not in the area under the cap, but the area behind the 'bulkhead' (the part of the recovery bottle closer to the back of the car). You may be able to move it with a small piece of wire, or even use a garden hose to spray water into the bottle (will make a mess). Did you do any maintenance lately? If you did a timing belt, or something on that side of the motor you may try popping the bottle loose from it's mount and checking the connector on the bottom.

Good luck.

Is it a coolant light or a check engine light because of a coolant code? Mine was throwing a coolant code, triggering a check engine light. Cause was a bad t-stat & coolant temp sensor.

Coolant warning light is still on. The coolant level is correct. I have been noticing the sweet smell of coolant inside the vehicle when the heat is on. Could it be leaking somewhere around the heater core? Would this trigger the warning light? Thanks.

I will bet the sensor is bad pretty common. But I have also seen the bottle go bad.

My 01 V70 has a coolant level light. I've never seen a coolant warning on mine. If it is a coolant level, then it would be the sensor. So does yours say warning or level? Perhaps other years or models use different terms.

Jerry

The sweet smell of coolant inside the car could be, and I hope not for your sake, a bad heater core. But if there is leakage inside the engine compartment it could be slight and boils/evaporates before it leaves a puddle on the ground. I'm still voting for the thermostat or the sensor that causes the light to go on.

The cooling system light goes on about five seconds after I start the car. It seems like most of you are voting for a bad coolant sensor, so that is likely what the problem is. It isn't overheating, and the coolant level is fine. There is that sweet coolant smell when the heat is running in the vehicle as well. Maybe the sensor doesn't like the cheap supertech coolant i used to top off the coolant level recently. I replaced the upper radiator hose after draining the radiator and topped it off with supertech coolant. I know the manual says to use volvo coolant only, but I like to deal with the local volvo dealer as little as possible...

same issue here. here's what fixed mine and the coolant light went out. fixed: leaky coolant bottle, coolant temp sensor, and thermostat.

the sweet smell inside the car is a coolant leak from the heater core. easy to get to and fix. parts online. DIY article around here somewhere.

good luck.

Thanks everyone for your input! I will replace the heater core if I notice I start loosing lots of coolant or the sweet smell becomes overpowering, even though I'm told it is relatively easy to replace. I am too cheap to replace the coolant sensor just to get rid of the warning light on the dashboard.