The only problem with using a level sensor vs pressure gauge is all it tells you is that there is a liquid around the sensor. With a pressure gauge you can not only tell if you have a sudden loss but also if your over pressuring and if your cap is opening when it should (may never loose fluid but if cap isn't holding pressure its more likely to overheat).
Block heater falling out
- Thread starter S-west
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Wyreth
Certifiable Noob
Other than the difficulty of plumbing a level sensor. (or at least I cannot think of a simple location that would actually give a usable reading) Why not have both?
It would be very simple. Hell I could post the parts list, schematic, and arduino sketch so anyone could make one. (assuming someone comes back with a good location for the level sensor. otherwise that would be left out)
It would be very simple. Hell I could post the parts list, schematic, and arduino sketch so anyone could make one. (assuming someone comes back with a good location for the level sensor. otherwise that would be left out)
jaluhn83
Full Access Member
ISSPRO makes a very nice coolant level kit - it's a bit pricey (~$100 IIRC) but well worth it and easy to install. Comes with a nice bung fitting you can solder/braze onto the top tank or make your own fitting if you want. As designed it has a big red warning light and a buzzer, but I just installed the light.
I wouldn't want to use pressure because the system pressure is not constant - when the engine is cold it's pretty much 0, and even at normal temp it may be close to 0. A level system is much more accurate - if you have a leak you're going to get a low level in the top tank before you loose too much from the system.
I wouldn't want to use pressure because the system pressure is not constant - when the engine is cold it's pretty much 0, and even at normal temp it may be close to 0. A level system is much more accurate - if you have a leak you're going to get a low level in the top tank before you loose too much from the system.
Top of water pump...there's a small port not used...install sensor there!
Drivers side head at rear above ex man where the port to the heater would be on the pass side....nother good sensor location!
JM2CW
Drivers side head at rear above ex man where the port to the heater would be on the pass side....nother good sensor location!
JM2CW
jaluhn83
Full Access Member
The other reason I can think of not to use a pressure sensor is that it woln't tell you if you have a slow leak - with a level sensor you get the alarm as soon as the level drops to a given point even if the system is still pressurized (for instance due to steam)
Umm hate to break it to you but coolant pressure once up to temp should be constant, exactly at whatever the cap is rated for. As far as a slow leak the pressure gauge would tell you because the pressure will be below what it should be (cap rating). In either the case of the pressure or level with a slow leak, temp would be the main indication, vs say your block heater falling out and causing a sudden lose of pressure and fluid level
jaluhn83
Full Access Member
1) I'm sure it was unintentional, but the "hate to break it to you" bit comes off as very arrogant and as if you're automatically assuming the person you're talking to is either 5 or an idiot....
2) I personally have not ever actually put a pressure on a cooling system under load to watch what the pressure does, but I suspect it's very unlikely that it stays constant unless it stays at exactly the same pressure constantly. The radiator cap is not really a pressure regulator - it's basically just a simple pressure/vacuum relief valve. That is, when pressure in the system exceeds the set (13 psi) it will release pressure, and when the system pressure drops below atmospheric (ie when the engine cools off) it opens allowing the system to refill from the overflow bottle. However, when the pressure in the system is between those 2 limits, the cap does nothing.
So, think about what happens when you're pulling a hill.... the system is going to heat up to say 220* causing a certain amount of expansion, pressure and flow into the overflow.... then you get to the top, load drops and engine cools back down to ~180*, with a consequent contraction of the coolant - pressure will now go down from what is was at 220* and this will become the new system pressure until it either cool off enough to pull water back in or heats up enough to hit or exceed 13 psi again.....
There's also a degree of surge in the system due to rpm change - try running the truck at high rpm with the cap off and you'll notice that the radiator level changes a bit. Not sure if this would be enough to matter for a pressure sensor though. Depends too on where you put the sensor - if it's on the outlet side of the water pump there will certainly be a pressure change with rpm.
I have personally had experience with a slow leak that caused a loss of water but would maintain pressure - I think it was caused by head cracks and would very gradually loose coolant but would fill with air/steam and maintain pressure. You could also have a leaky overflow hose or empty overflow tank which would cause the cooling system to develop an air bubble in the top tank. I don't think this would be big enough to cause an issue, but it might be. In either case, the pressure sensor would show pressure, where a level sensor would tell you the level was low. The problem I had would get bad enough to start trying to overheat though it never got bad enough to really be bad. The coolant level sensor would catch it well before it ever got low enough to start overheating though.
The level sensor setup I have was very simple to install - it goes in the top tank. Just drill a small hole (~3/8" IIRC) and solder in the bung.
You could also just use a float sensor which would be cheaper and easier to wire, though more difficult to install. You might have more issues with slosh though. The one I have is capacitive - no moving parts.
I will also note that I have never heard of a coolant pressure sensor being used anywhere for an alarm system, whereas level sensors are very common both for industrial and automotive OEM use.
2) I personally have not ever actually put a pressure on a cooling system under load to watch what the pressure does, but I suspect it's very unlikely that it stays constant unless it stays at exactly the same pressure constantly. The radiator cap is not really a pressure regulator - it's basically just a simple pressure/vacuum relief valve. That is, when pressure in the system exceeds the set (13 psi) it will release pressure, and when the system pressure drops below atmospheric (ie when the engine cools off) it opens allowing the system to refill from the overflow bottle. However, when the pressure in the system is between those 2 limits, the cap does nothing.
So, think about what happens when you're pulling a hill.... the system is going to heat up to say 220* causing a certain amount of expansion, pressure and flow into the overflow.... then you get to the top, load drops and engine cools back down to ~180*, with a consequent contraction of the coolant - pressure will now go down from what is was at 220* and this will become the new system pressure until it either cool off enough to pull water back in or heats up enough to hit or exceed 13 psi again.....
There's also a degree of surge in the system due to rpm change - try running the truck at high rpm with the cap off and you'll notice that the radiator level changes a bit. Not sure if this would be enough to matter for a pressure sensor though. Depends too on where you put the sensor - if it's on the outlet side of the water pump there will certainly be a pressure change with rpm.
I have personally had experience with a slow leak that caused a loss of water but would maintain pressure - I think it was caused by head cracks and would very gradually loose coolant but would fill with air/steam and maintain pressure. You could also have a leaky overflow hose or empty overflow tank which would cause the cooling system to develop an air bubble in the top tank. I don't think this would be big enough to cause an issue, but it might be. In either case, the pressure sensor would show pressure, where a level sensor would tell you the level was low. The problem I had would get bad enough to start trying to overheat though it never got bad enough to really be bad. The coolant level sensor would catch it well before it ever got low enough to start overheating though.
The level sensor setup I have was very simple to install - it goes in the top tank. Just drill a small hole (~3/8" IIRC) and solder in the bung.
You could also just use a float sensor which would be cheaper and easier to wire, though more difficult to install. You might have more issues with slosh though. The one I have is capacitive - no moving parts.
I will also note that I have never heard of a coolant pressure sensor being used anywhere for an alarm system, whereas level sensors are very common both for industrial and automotive OEM use.
Wyreth
Certifiable Noob
Actually, that's exactly what a pressure regulator is. A piston with a calibrated spring that seals to a seat when system pressure is = spring pressure. And yes, at operating temperature, the cooling system operates under constant pressure. If your cap is working correctly it will maintain approx 13psi under changing driving conditions.
I run an aluminum radiator, there would be nothing simple about installing this on my top tank. Not discounting a level sensor. Myself I would want both, they both give good and different kinds of information.
Just saying mine would have to go in the port on the head (as my mechanical temp gauge is currently plumbed to the water pump.)
jaluhn83
Full Access Member
Okay, that was poorly worded - yes it is a pressure regulator, but the point is that the stock setup does not necessarily have 13 psi in it at all times - it's somewhere between 0 and 13.
I currently have an aluminum radiator - I drilled and tapped a 1/4 NPT hole in the top tank for the level sensor. Took about 3 minutes. The thickness of the metal is marginal for a good thread, but it's enough and with some permetek it works fine. Ideally you would probably want to weld a thicker plate on and then tap that, but yes this is a bit harder.
I currently have an aluminum radiator - I drilled and tapped a 1/4 NPT hole in the top tank for the level sensor. Took about 3 minutes. The thickness of the metal is marginal for a good thread, but it's enough and with some permetek it works fine. Ideally you would probably want to weld a thicker plate on and then tap that, but yes this is a bit harder.
HammerDown
Full Access Member
I fill the rad and then remove the heater hose from the heater core that's going into the block > gotta use a small funnel on the hose end and be patient, cause when it get's to the top it will burb out some air/coolant
I was thinking of doing this but wasent exactly sure how it would work with all the air trying to escape haha. I guess I'll give a try I have an extra thermostat housing gasket but any way to avoid taking it off is good haha
jaluhn83
Full Access Member
No need to take anything off unless the little ball in the thermostat neck is stuck, then you may need to vent it from a heater hose or something.
As designed there's a small ball bearing in the thermostat neck that allows air to escape when you fill it. You may get a bit of air still stuck but it'll work it's way out. After draining the cooling system it's always wise to start the truck and let it idle or run under light load until it gets warm enough to open thermostat, then after letting it idle for a bit (couple minutes should be enough) shut it off and let it cool - this will effectively burp the system of any remaining air and even if there's anything trapped it woln't get hot enough to hurt anything. Obviously keep an eye on it too just in case.
As designed there's a small ball bearing in the thermostat neck that allows air to escape when you fill it. You may get a bit of air still stuck but it'll work it's way out. After draining the cooling system it's always wise to start the truck and let it idle or run under light load until it gets warm enough to open thermostat, then after letting it idle for a bit (couple minutes should be enough) shut it off and let it cool - this will effectively burp the system of any remaining air and even if there's anything trapped it woln't get hot enough to hurt anything. Obviously keep an eye on it too just in case.
At least you had those girls smiling at you for a little bit. A bright moment?
That sucks. Things like this aren't the worst thing in the world, yet they can cause some serious crap. It's the reason I run synthetic oil in everything. I lost coolant once on a HOT summer day while running the AC flying down the highway in my GMC. Pegged out the temp gauge, even after immediately taking the side of the road and shutting down. Got hauled home and when everything was cooled I fixed the issue, added coolant and was worried I cracked my head(s) or warped something or whatever. But I think the synthetic saved my ass. Sure it was just a 350 but after changing the oil with some fresh synthetic, I've been running the engine since in the truck and have not had any issues related to the incident. The engine was a Goodwrench crate and has 300,000 on it, has had synthetic since new and doesn't burn oil. Just a problem related to a burned out stock fuel pump that lasted the entire 365,000 miles.
The point I was trying to make with all of the extra, somewhat related information, was that the synthetic oil in the engine helped cool things enough when I lost my coolant that time. Of course when I installed it I also installed an engine oil cooler with the foresight of towing a lot of stuff on the farm. On a related note, I run synthetic through my diesels as well and they all have engine oil coolers. The Internationals have theirs, and the Detroit 6.2s have lines running into the radiator and an extra cooler I can valve off in the cold weather. But speaking of the 6.2s, they have those coolant level sensors mounted in the radiators. Works well since I have a small leak on my M1009.
That sucks. Things like this aren't the worst thing in the world, yet they can cause some serious crap. It's the reason I run synthetic oil in everything. I lost coolant once on a HOT summer day while running the AC flying down the highway in my GMC. Pegged out the temp gauge, even after immediately taking the side of the road and shutting down. Got hauled home and when everything was cooled I fixed the issue, added coolant and was worried I cracked my head(s) or warped something or whatever. But I think the synthetic saved my ass. Sure it was just a 350 but after changing the oil with some fresh synthetic, I've been running the engine since in the truck and have not had any issues related to the incident. The engine was a Goodwrench crate and has 300,000 on it, has had synthetic since new and doesn't burn oil. Just a problem related to a burned out stock fuel pump that lasted the entire 365,000 miles.
The point I was trying to make with all of the extra, somewhat related information, was that the synthetic oil in the engine helped cool things enough when I lost my coolant that time. Of course when I installed it I also installed an engine oil cooler with the foresight of towing a lot of stuff on the farm. On a related note, I run synthetic through my diesels as well and they all have engine oil coolers. The Internationals have theirs, and the Detroit 6.2s have lines running into the radiator and an extra cooler I can valve off in the cold weather. But speaking of the 6.2s, they have those coolant level sensors mounted in the radiators. Works well since I have a small leak on my M1009.
jaluhn83
Full Access Member
Not going to disagree that synthetic oil is a good thing for an engine, but I doubt it had much to do with not damaging the engine when it overheated... Synthetic is going to tolerate getting hot better ie, less damage to the oil) and to some extent lubricate better at very high temp, but neither of those are really the major concern with a loss of coolant - the oil, synthetic or otherwise does little to reject head from the engine unless you have a separate oil to air cooler and even then it's not going to do much except maybe keep the pistons a bit cooler. The oil does have a major role in heat transfer, especially in the idis (due to oil squirters) but it's just transferring the majority of the heat to the coolant for ultimate rejection to the air. The degree of cooling that you do get from the oil should be pretty much independent of whether it's synthetic or not. The main enemy in overheating is the inability to reject much heat from the engine and the essentially complete loss of cooling to the head & combustion chamber, leading to thermal stress, cracking, warping and heat gasket failure.
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