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Can you refill engine coolant without flushing or draining?
Hi, everyone I purchase a pre-owned 2013 Lexus RX 350 with mileage around 37,800 miles at purchase. I was inspecting the engine coolant fluid level and it was below the minimum level line, I purchase the Toyota super coolant (PINK). My question is can you just add the antifreeze coolant without doing the draining radiator or flushing the system? Right now the mileage of the vehicle is at 40,500 miles, I am planning to do a long distance trip next month and ideally no overheating issues hopefully. Thank you for any suggestion in advance.
Check it every once and awhile because you really shouldn't lose any coolant unless its leaking or being burned up in the cylinders (highly doubt either of these issues though).
Last edited by jshow816; Jul 10, 2017 at 09:30 PM.
That's fine to add coolant to the expansion tank. Just read instructions on the coolant you bought, if it needs to be diluted with distilled water.
I had to do that to my Audi recently. All fluids in the Lexus are fine though, after 5 years and 60K miles of ownership.
If you are short by less than a cup [not repeatedly], you can just add distilled water. If you have multiple vehicles, it may we worth keeping a premixed jug, but for minor add, the % mix will be very slightly lower than 50/50.
Other thing to watch out is that adding a cup in the overflow reservoir in freezing conditions can be bad as then the reservoir can freeze over. I would go 1/4 cup each time and fill up in 3 or four days of driving.
If you have the premixed stuff, just add at will. But investigate why it is falling low.
Hi, everyone I purchase a pre-owned 2013 Lexus RX 350 with mileage around 37,800 miles at purchase. I was inspecting the engine coolant fluid level and it was below the minimum level line, I purchase the Toyota super coolant (PINK). My question is can you just add the antifreeze coolant without doing the draining radiator or flushing the system? Right now the mileage of the vehicle is at 40,500 miles, I am planning to do a long distance trip next month and ideally no overheating issues hopefully. Thank you for any suggestion in advance.
It is fine to add coolant to the over flow reservoir, just don't over fill it.
The question that needs to be asked is did you check the level in the tank with the engine hot or cold? Since it was low I am guessing that it was cold, so just fill it up to the minimum level.
If the motor (and more importantly the coolant system) was hot when you saw it low you have a different and possibly bigger problem.
Engine was cold during inspection. My coolant is already pre-mixed looks like that on the image.
I filled it half way between full and minimum line, thanks everyone.
Just to be clear on what you actually did, you did not top off your coolant, but instead added to the expansion tank.
In simplified terms, the tank is there so as the engine heats up and the coolant get's hot and expands, it has a place to go. When it cools down it gets sucked back out of the reservoir and into the system again.
I would guess that half full will be fine, but you might want to check the level with the engine hot to make sure you did not over fill the thing.
Any overfill will either fit into the "designed" head space in that reservoir or overflow to the ground. Aside from someone's environmental concern, the overflow is a "no harm no foul" scenario for the engine itself.
As to whether the OP's action of adding coolant to the reservoir "is" or "is not" considered "topping off the coolant" is completely a matter of perspective and semantics. Regardless of what you want to call it, his action was a form of "topping off" the overall coolant system's level (or amount) of coolant, even if he was not technically topping off the radiator per se.
Any overfill will either fit into the "designed" head space in that reservoir or overflow to the ground. Aside from someone's environmental concern, the overflow is a "no harm no foul" scenario for the engine itself.
As to whether the OP's action of adding coolant to the reservoir "is" or "is not" considered "topping off the coolant" is completely a matter of perspective and semantics. Regardless of what you want to call it, his action was a form of "topping off" the overall coolant system's level (or amount) of coolant, even if he was not technically topping off the radiator per se.
Over the years I have had more than one person say they had a vehicle that was overheating, they added coolant, and it was still overheating, only to finally figure out that they were adding to the overflow and not the radiator.
Of course if they keep filling the overflow and don't seriously overheat the motor it will eventually get into the system but just filling it up correctly is a much safer option.
Hello everyone I am back for more question. I noticed that my coolant fluid has been empty again and checking something is wrong. The coolant reservoir cap has a PVC hose attaches to the cap itself. However, the PVC hose isn't attach to other part of the vehicle I am guessing that is why the coolant is existing the reservoir.
This is not the exactly my reservoir picture, but is the same concept. Hose is just hanging out in the open, is that suppose to the case with the 2013 RX 350 model? Thanks for any help.
The hose in the picture is referred to as overflow pipe.
In some vehicles it overflow is vented out (mostly the pipe is long enough to reach past the bottom shield of the engine.In other vehicles, it is taken to an overflow tank which acts as an additional reservoir. Once the air has been expelled the volume of coolant is exchanged between the overflow and the radiator.
Back to your RX. Have you topped up the radiator (engine cold). If so you may need to do it a few times (3 or 4 times max) to purge out all the air in the coolant. There is a process to purge the air. For leaks, you can look for drip pool under the engine ,,, light pink (for Toyota coolant).
Engine was cold, I am not sure how to top out the radiator. The plastic covers over the engine bay I only have access to the engine coolant reservoir compartment. I was filling the engine coolant reservoir, do I need to remove all the plastic cover to get to the radiator? Radiator use engine coolant or other type of fluids? Thanks once again.
That hose is the same on my 2010 and I do not loose coolant. You need to have a shop run a pressure test on your cooling system to find the leak. It is likely a bad hose clamp or maybe you just need a new radiator or coolant filer pressure cap as they loose the ability to maintain pressure over time and should be replaced. In my opinion, that is the first thing to try as these caps are cheap. However, if it is not on the radiator itself, it is nearby on the engine. You will have to remove some of the plastic engine covers to find it or take it to a shop as it sounds like you may be reaching the limit of your repair abilities.
Can you refill engine coolant without flushing or draining?
