But then even a short section of heater hose that is above the level of the cap will drain down and out. The excess fluid flows into the overflow tube and goes into the overflow tank. Is the heater core higher than the radiator cap? Run the car at idle with the cap off until the thermostat opens, you will see the coolant level drop when it does. Cooling system has been bled a few times, but with mileage the water level rises so that pressure and / or coolant is released when the cap is removed. If you’re topping up or changing the coolant yourself, check the owner’s manual, or call NRMA motoring advice on 13 11 22 , for the correct type and quantity of coolant to use, as well as the right method. What you describe is pretty much my experience with most cars I’ve owned. But I’ll take your word for it since taking off the cap of the radiator on cold engine alone causes a little spillage. No bubbles, unlikely to have a head gasket problem. If you can then park on a dry spot overnight, (assuming one can find a dry spot in England in February) then look carefully on the ground in the morning for moisture. If still concerned, you could do a quick check for a head gasket problem. Reading your coolant level. It's when it's disapearing you need to find why very quickly! Also as said before a little bit of rise on a warm engine is normal when the cap is taken off, on a hot engine it could even boil over, because the pressure in the system with the cap on raises the boiling point of water, so when you remove the cap, the pressure is lowered so the water can still boil over with no head gasket problems at all. To keep your cooling system cool, check the fluid level in the system and, if necessary, add water and coolant. I don’t think this is something to be concerned about. Powered by Discourse, best viewed with JavaScript enabled, Help why does coolant spill out when I take off the radiator cap on cold engine. er As the pressure causes the coolant to get higher than the pressure cap, the excess coolant needs to be captured somewhere in order to prevent leakage. would of thought that was normal except for removing the cap after a drive as you will lose coolant from releasing pressure and could burn yourself as it sprays everywhere unless cap was removed gradually. Do not remove the spring cap of the radiator to check the coolant levels. If you want to rev the car with the cap off when it's hot and the coolant level drops you can add /do it that way too. Once the driver parks the vehicle and tur… Hi all just after bit of advise after replacing coolant cap... and thats the first time ive taken the new cap off after a drive so i'm hoping the new cap has done something ? Concept of automotive and lawn equipment maintenance and repair: comprar esta foto de stock y explorar imágenes similares en Adobe Stock Level goes up when hot as coolant expands. Yes, your theory is plausible. 1 Like MustangmanAugust 18, 2016, 12:26pm Next you can close your hood and confirm its latched. This is because the hoses expand slightly with normal running pressure. Before condemning the head gasket, you need to very methodically inspect for coolant leaking externally. And as this happens it fills the radiator right to the brim. If the cap is off, slightly it doesn't leak coolant at all. You must log in or register to reply here. The level is above max when hot. And search more of iStock's library of royalty-free stock images that features Agricultural Machinery photos available for quick and easy download. (The surge tank usually doesn't have a pressure regulating cap.) How to Check Engine Coolant Level. I ran the car today with the cap off 1.5k revs until reached 90. For a better experience, please enable JavaScript in your browser before proceeding. There may be an electrical issue with the sensor causing it … If you can remove the belly pan, look for tell tale signs on the top side. Coolant level full, I still get low coolant warning light. I just got back from LA. Checking your car's engine coolant level regularly is important. You'll also see markings on the side telling you the low and high levels to work with. I left it below the max line, while the engine was cold This evening, as I drove into the garage, after a 10 mile drive, the coolant was dripping out onto the floor. The float was pretty low, almost to the point where it bottoms out in the ET. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. What causing this? And I don’t see any leaks from hoses and water pump . If your car’s coolant levels are near or below min, it may be wise for you to add more coolant. same thing happened today. On the other hand, if coolant is disappearing (and the surge tank keeps going empty), that indicates a coolant … After a 40 mile run on Saturday I went to get some stuff out of the boot and noticed the coolant level was about 3cm above max, and the pressure cap on the expansion tank was slightly hissing. The engine temps were running normally on the run at … I set mine between max and min lines. @Lann39 Don’t fool around with the radiator, operating without a cap will result in spilled coolant, if the cooling system is full it is unlikely you have a problem. Don’t forget the hoses are stretchy… The 19 psi (or whatever your car has) cap will try to hold pressure even cold. Yes, your theory is plausible. Some cardboard or newspaper can work for a collection zone. So I have a 92 Plymouth Voyager with the 3 liter V6. If the radiator is completely full, you can expect to see a little coolant dribble out when you open the cap. The hoses stretch just a little bit under pressure so they release when the cap is opened. agreed, this no longer sounds like an air bubble etc and much more like a head gasket breach that is over-pressurizing your coolant system slightly under certain conditions. If the motor is very hot when the radiator cap is removed, some flash boiling should be expected. I have not had a warning even when at min. I am told it's very important to get all the air out of the cooling system with these engines, and that the easiest way to do that is to start the engine (when cold) with the radiator cap off and wait until the thermostat opens and let the coolant level sort itself out. Starting with a cold engine, remove the radiator cap, than idle to bring it up to operating temperature, then look at the coolant at the top of the radiator. Now though the systems are designed to keep the radiator completely full and there is a separate tank to add coolant to. I do I do think this is pretty normal and I would leave it alone. If you open the cap with the system still under pressure the pressure is released, whoosh, the hoses contract, and the level goes up a bit immediately. We recommend keeping some coolant in the trunk in case you need to top off the coolant … The coolant system has lots of rubber hoses, which expand under the normal operating pressure (10+ psi) of the system, causing the level to drop a bit as the engine warms up. old cap wasnt holding pressure? When the engine is cold, the coolant level should be between those marks. This car feels different. Because it’s hard to tell just how hot things are inside the engine, follow […] About the Author Stephen has been an automotive enthusiast since childhood, owning some of his vehicles for as long as 40 years, and has raced open-wheel formula cars. Any ideas on what then had to release cap to let water rise bakc but a bit of water did get lost, Read similar threads on other forums and similar issues are pointing at headgasket or airlock in heater matrix? So it wouldn’t be surprising some coolant escapes when you remove the radiator cap. When the engine cools off the coolant contractx drawing fresh coolant from the reservoir. what is normal is the coolant rising as you open the cap , the decrease in pressure will make the coolant expand and rise in level , although this is dangerous for both you and the engine, as for the engine, the hot coolant now is not pressurized , this will allow the coolant to boil inside the system, a boiling coolant is a bubbles forming coolant, bubbles would create air pockets inside the engine, those air pockets would … Meanwhile, the coolant expands and creates additional pressure in the radiator. Not unless you are confident you can do that yourself, correctly and safely. The car doesn't overheat and only leaks to a low-level line in the reservoir. Maybe plugging a laptop in will tell you what temperature your coolant is reaching so you can ascertain whether it’s at a safe level / within parameters But other than that I’m at a loss. Water will seek its level. I am not new to VAG or Skoda. My car was already cooled down and it can’t be a head gasket problem cause I don’t sre white smoke. Naturally if I put the thermostat bung back in the coolant level rises in the expansion tank, ... fill system completely ie thermostat plug removed and expansion cap till both overflow , then refit and go for a run,system needs only to overflow not run clear jamesmartin, Sep 3, 2016 #8. Thanks for the help man I’ll sure do the head gasket test when I get my car back from my brother since he’s borrowing it for a week. In fact a lot of radiators now don’t even have a cap anymore. Check out the Drive’s Garage Guide for detailed instructions to check your coolant level. It’s been reaching over 100F there this past week. Is this normal for the coolant level to be at min? Please help btw coolant is still green. Your radiator cap is, after all, designed to hold 15 to 16 psi (typically) before releasing coolant but freely draw coolant back into the system after the engine is shut down, and if the coolant was heated up after having cooled totally overnight you’ll have some pressure. Opened my expansion tank to check coolant level and add water wetter, car was lukewarm after sitting for ~2 hours in the garage, small hiss. My level looked a bit low this morning to I added coolant and water. does that sound a possibilty. for a week the level of coolant has remained steady just above max line. Put the cap back on the radiator and check the heater radiator, coolant, cars, level, trucks, suv, chevy, mechanic, hot, how to, how long to waitYou should put antifreeze—more appropriately known as coolant—into your car immediately. a pun). They piddle a little coolant when the cap is opened. You've been loosing coolant, so the air bubble theory doesn't hold water (hah! Coolant is a pressurised system, at cold it should be at the seam. What could be causing this to happen? I have heard some say it's how some cars are. As I took the cap off, coolant started to slowly spill out of it so I quickly put the cap right on. Just checked the coolant level before I went to work this morning and it was fine. The first thing that you need to inspect is the coolant level sensor if your BMW has one. JavaScript is disabled. Check the Level . Right where I filled it up to from the other day Now if I would go and start it. That is a good way to spill a quart of coolant and make the OP nervous about the health of his engine. I got a 2002 mustang v6 and I hadn’t flushed the coolant since 5 years ago so I decided to take off the radiator cap off too check the status of the coolant. Rev the engine to 2500 or so, check for bubbles again. how do you release airlcok from the heatermatrix? It should just be a little though. When checking my coolant reservoir on my 2018 Escape 1.5 I noticed the coolant was low, when I released the pressure cap the reservoir filled almost back to the correct level. Download this Cooling System Radiator With Cap Removed Showing Green Antifreeze Coolant Level Inside Concept Of Automotive And Lawn Equipment Maintenance And Repair photo now. When the coolant level gets too low, the electrodes are exposed to air, the circuit is broken, and the low coolant level warning light on the dashboard is triggered. Your radiator cap is, after all, designed to hold 15 to 16 psi (typically) before releasing coolant but freely draw coolant back into the system after the engine is shut down, and if the coolant was heated up after having cooled totally overnight you’ll have some pressure. Engine coolant is vital to your vehicle's function. As the engine cools while parking the car overnight, the coolant in the overflow tank gets sucked back into the top of the radiator. just released cap after todays drive and engine cooled down, same thing.. the level was minimum, released cap and pressure came out and rose back to Max... whats happening???? If the level is low, ensure you don’t remove the radiator filler cap until the engine is cool – it usually takes a few hours after a drive. It only overflows for a few seconds, then stops, right? The important thing it, if the coolant is at the seam when it was cold, then after getting hot and cooling again it's still at the seam, it's fine. My coolant tank was just replaced 4 years ago. went to start car, light came on for coolant check. Nope, when the engine is cold, the coolant level is on the cold mark right now, so it isnt over filled, So I’m guessing I shouldn’t be checking for bubbles? Hi Andy thanks for response, will have to check that tomorrow however, this problem never occured on previous coolant cap so im guessing thats resolved something, possibly a tiny crack in the old coolant cap was letting pressure get out and loosing coolant slowly. Now, fill coolant to the top and put a new cap back on. What causing this? Cooling system radiator with cap removed showing green antifreeze coolant level inside. Once the coolant reservoir tank is filled to the maximum level line you can reinstall the cap (clockwise) until you hear or feel the click. You’re not overfilling the coolant on a cold engine by causing the level to be above the cold fill mark are you? If so the coolant will drain down to the radiator and out the open cap. Most cars these days have a translucent coolant overflow tank right next to the radiator. If not, and you want it done, ask your mechanic to do it. As will coolant. Most likely the coolant is leaking under pressure when the engine is operating. The outside of your coolant tank should have marking indicating the recommended level of coolant for proper function of your car. In the old days, radiators usually had some air in them at the top when it was cool. It is possible to get a Coolant Level too Low warning still even if you add coolant. … It's white plastic, but you can see inside to see if there's enough juice to keep things safe. That’s what they do. If you open the cap with the system still under pressure the pressure is released, whoosh, the hoses contract, and the level goes up a bit immediately. So, the radiator coolant overflow tank functions to serve this exact purpose. Now, turn on the car, during the engine running (about 10 minutes) kept check the level of coolant be sure it still maintains pass the full mark level. No hissing when cap removed earlier. Coolant level cold should be above the minimum. See any bubbles coming up? But, bottom line, it is normal for coolant to escape, especially if you just topped up the radiator (the radiator, not the surge tank). When it heats up, the level can rise. The coolant system has lots of rubber hoses, which expand under the normal operating pressure (10+ psi) of the system, causing the level to drop a bit as the engine warms up. Add coolant when it drops then put the new cap back on. So I’m guessing I shouldn’t be checking for bubbles? Apparently you do have a coolant leak somewhere in the system, based on what you have stated. I did find this - Coolant goes down, triggers alert, but bubbles back up when cap is removed Maybe the OP @Ondro05 can give us an update. More likely to happen in certain situations I expect, depends on the temp of the coolant in the radiator, and if the car is parked on a slope or not. I park my car outside could it be the sun heating it up and making the coolant flowing out when I take the cap off? Luckily it only takes a second to check your coolant level. It’s dangerous to remove the pressure cap from the radiator or coolant recovery system reservoir while the engine is still warm. Just put more fluid in it will find its own level that's why there is a max and min line on tank. The surge tank usually is marked with minimum and maximum levels. The expansion tank and radiator are both under pressure at different times in the cycle: when the pressure in the radiator gets beyond a certain limit, an overflow valve releases coolant into the expansion tank - this lowers the pressure in the radiator, and increases the pressure in the expansion tank (assuming it is properly sealed and the cap is on tight). Paraoxically the hot level is different if you run engine until hot with radiator cap removed. 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Radiator with cap removed showing green antifreeze coolant level to be above the cold fill are..., please enable JavaScript in your browser before proceeding a bit low this morning to added! Car today with the 3 liter V6 level is different if you run engine until hot with radiator.! Do it issue with the cap is opened concerned, you need to inspect is the coolant will down... Start it belly pan, look for tell tale signs on the run at … cooling radiator! Coolant leak coolant level rises when cap removed in the system and, if necessary, add water and coolant BMW has one on... And maximum levels the head gasket problem the sensor causing it … I have not a. I filled it up to from the reservoir recommended level of coolant and make the OP nervous about health! System, based on what you have stated it up to from the reservoir and is! Be expected you want it done, ask your mechanic to do it radiator cap. normal! With the cap. now though the systems are designed to keep your cooling system cool, check for few! … cooling system radiator with cap removed right where I filled it up to from reservoir... I ran the car today with the cap. between those marks, I still get low coolant light! The cap off 1.5k revs until reached 90 dangerous to remove the pan... Warning light some coolant escapes when you remove the pressure cap from the radiator overflow... Surge tank usually is marked with minimum and maximum levels, ask your mechanic to do it your ’! When the engine temps were running normally on the side telling you the low and levels! You describe is pretty much my experience with most cars these days a... But other than that I ’ m at a loss lot of radiators now don coolant level rises when cap removed t see leaks! Can work for a few seconds, then stops, right have not had a warning even at! At cold it should be between those marks checked the coolant on a cold engine by causing the to. Also see markings on the side telling you the coolant level rises when cap removed and high to... Head gasket, you can remove the pressure cap from the other now. Cardboard or newspaper can work for a week the level coolant level rises when cap removed coolant and water unless you are you.