So you are saying the engine never overheated, and the car seems fine?
Yes the alternator belt drives the water pump, but 8 freeway miles where your engine doesn’t overheat is the equivalent of walking a short distance in slightly warm weather a little bit thirsty. The car is fine, just replace the belt and you will be 👍
It's probably fine, and I don't say this to scare OP, but you saying "the engine didn't overheat" is not necessarily true.
Your coolant temperature gauge is not going to give an accurate reading of the coolant temperature in the engine when there is no coolant being pumped through the engine.
A small amount of coolant is going to get sloshed around naturally because of physics and stuff, but largely the coolant isn't going to move around much without a water pump. The temperature of coolant in the radiator vs inside the engine vs at the coolant temperature sensor location is going to vary.
Again, I don't say this to scare OP. If the car seems fine, I'd throw a new belt on, check the coolant level, and drive it. If it doesn't overheat I wouldn't stress about it.
I agree with what you said, but I just don’t see a world in which a natural aspirated small displacement engine will overheat with 8 miles on the freeway anyways. Maybe if it was 85+ degrees out with heavy traffic, but still. My KLR650 and CBR600rr, both with oil temp gauges, are more than 40% cooler on the freeway than in traffic.
The question becomes how much airflow his actual engine blocks gets/how much heat it can dissipate on the highway and if that's enough to keep it cool. No water pump is no cooling flow at all. The coolant is just sitting in there. His sending unit is just sitting there like your pinky would in a cup of water. This isn't like a fan failure where you can rely on the air stream in its place. It's possible that as coolant got hot enough it was forced out of the block and into the radiator, and it was able to suck in enough coolant from the radiator (already cooled down) to be OK.
But boil over is real regardless if the pump is turning or not. If your overflow bottle wasn't boiling and you didn't see any steam., smell any coolant or see white smoke you're probably OK.
Your cooling system was also still under pressure which raised the boiling point of the coolant beyond 212F.
Be on the lookout for white smoke when starting up. That would indicate a head gasket leak from a warped head. A used oil analysis would be an extra step to see if you have excess aluminum in the oil from the piston trying to seize in the bore.
But in general, if the car runs fine after the belt replacement, don't worry about it
Check for leaks on all the mating surfaces(especially the head), glittery oil and for mixed/burnt fluids. Do it for every trip for a while just to be safe. Also listen for odd sounds.
So you are saying the engine never overheated, and the car seems fine? Yes the alternator belt drives the water pump, but 8 freeway miles where your engine doesn’t overheat is the equivalent of walking a short distance in slightly warm weather a little bit thirsty. The car is fine, just replace the belt and you will be 👍
It's probably fine, and I don't say this to scare OP, but you saying "the engine didn't overheat" is not necessarily true. Your coolant temperature gauge is not going to give an accurate reading of the coolant temperature in the engine when there is no coolant being pumped through the engine. A small amount of coolant is going to get sloshed around naturally because of physics and stuff, but largely the coolant isn't going to move around much without a water pump. The temperature of coolant in the radiator vs inside the engine vs at the coolant temperature sensor location is going to vary. Again, I don't say this to scare OP. If the car seems fine, I'd throw a new belt on, check the coolant level, and drive it. If it doesn't overheat I wouldn't stress about it.
I agree with what you said, but I just don’t see a world in which a natural aspirated small displacement engine will overheat with 8 miles on the freeway anyways. Maybe if it was 85+ degrees out with heavy traffic, but still. My KLR650 and CBR600rr, both with oil temp gauges, are more than 40% cooler on the freeway than in traffic.
The question becomes how much airflow his actual engine blocks gets/how much heat it can dissipate on the highway and if that's enough to keep it cool. No water pump is no cooling flow at all. The coolant is just sitting in there. His sending unit is just sitting there like your pinky would in a cup of water. This isn't like a fan failure where you can rely on the air stream in its place. It's possible that as coolant got hot enough it was forced out of the block and into the radiator, and it was able to suck in enough coolant from the radiator (already cooled down) to be OK. But boil over is real regardless if the pump is turning or not. If your overflow bottle wasn't boiling and you didn't see any steam., smell any coolant or see white smoke you're probably OK. Your cooling system was also still under pressure which raised the boiling point of the coolant beyond 212F.
Just FYI The pulley on my son's NB was worn and the belt kept breaking. Check it out as it could save you blowing up the motor like he did.
Be on the lookout for white smoke when starting up. That would indicate a head gasket leak from a warped head. A used oil analysis would be an extra step to see if you have excess aluminum in the oil from the piston trying to seize in the bore. But in general, if the car runs fine after the belt replacement, don't worry about it
Was your engine warm when the battery light came on?
It’s for charging your battery. Get a new belt.
The alternator belt also runs the water pump. So the question is if the engine overheated and it just didn’t show it.
Ah. That might be a problem then.
Check for leaks on all the mating surfaces(especially the head), glittery oil and for mixed/burnt fluids. Do it for every trip for a while just to be safe. Also listen for odd sounds.