Waynewine

Yesterday I drained my 2015 NX200t’s radiator then filled with distilled water and 1 bottle of Preston Flush & Clean. I drove test about 20 minutes and every thing was fined. I drained it out and filled with Preston 50/50. This morning I drove test again and the car was overheated. I turned the engine off and let it cool down before test drive again. But it is still overheat. Anyone know what the problem might be?
the radiator fans work when the temperature gauge needle is at middle or higher. The temperature of the end of radiator hose at the engine block (connect to the thermostat housing?) is very hot but only warm at the end connect to the bottom of radiator. There is pressure at the Coolant reservoir but no pressure at intercool bottle. I am thinking that the thermostat might be stuck close.
Any suggestions for troubleshooting will be and also show me the procedure to replace the thermostat will be appreciated.

Clutchless

You probably filled the radiator too fast and failed to open the engine block coolant air bleed screw and have air in the cooling system. There is probably nothing wrong with your thermostat.
You need to fill the radiator-cooling system very slowly so the coolant has time to flow into the engine and displace air. This means taking at least 5 minutes to pour. Then the engine block air bleed screw must be open. Usually it is under the engine cover and on top of the engine block. Look for a small (10mm wrench) bolt with a hole in it that sticks up. This is the Toyota 2.0 engine shared by many models, look for Corolla, Camry or RAV4 coolant change instructions. You want the bleed screw open as you fill it until coolant comes out. Close it and then after you start the engine open it again and watch the air bubble out until coolant alone comes out.
Only use Toyota coolant.
Be sure your heat is on. Do all this while it is idling and wait until the cooling fans come on to be sure you are at open thermostat temp. Good Luck. The engine is too expensive to replace to be the place to learn how ot work on your cooling system. If unsure of what you are doing, take it to a shop, even your local gas station.

Use the LIsle spill free funnel to fill your radiator as it reduces the air in the system. https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds

Look at this starting around 3 minutes 45 seconds into it

Waynewine

Thank for your helpful response. I followed your instructions to open the 2 bleeding crews and filling the coolant into the reservoir until the coolant came out from these crews. The car is no longer overheat.

Bravo001

Hey Waynewine! Can you please help me with the photo to locate the bleed screw? I am having same issue with my nx.

Waynewine

There is two crews: one is to the left of the oil dip stick and other is white plastic to the left of brake fluid reservoir.

Waynewine

android970

Registered just to comment, plus im on a little bit of liquid courage, if you know what i mean , but i have an 08 gs350 and the best method for me was to buy a food thermometer (one that you use to check meat temperature, with the metal stick end) and stick it into the radiator, with the cap off obv (cold engine, im sure you know but just a disclamer) and kick on the a/c, so temp can rise above 200, by then the thermostat should open up, and fans should kick on, at this point just fill up to appropriate level through the radiator and then you should be golden, give the rad hoses some squeezes and then put the rad cap back on, drive around and you should be good. I had a bad air pocket that caused my temp to almost get to overheating range and then would drop down to normal range when the fans kicked on. Now the fans kick on and the temp gauge doesnt move. Best of luck, i hate dealing with car problems and right about had a mental breakdown, im planning on selling my gs350 by next winter and buying a 4runner or tundra. i miss my old 08 camry but that thing was burning oil (2azfe engine)

chuyrobles

How is the intercooler coolant flushed? I'll be doing a flush on sister's '15 NX at her next oil change and will replace belt and coolant. I've never worked with an intercooler before and did not find a youtube video in my first attempt. Her manual says the regular cooling system holds 8.3 qts and the intercooler holds 3.1 qts. Manual doesn't say how to flush the intercooler. Will it drain out when I open the radiator drain ****? Any special procedure or parts to replace for the intercooler? I assume the block has a coolant drain plug? One on each side? I can probably figure this out when I get the car.

chuyrobles

Did the coolant flush on sister's N200T. Interesting the radiator doesn't have a radiator cap. There are two reservoirs - the radiator reservoir is on the passenger side and the intercooler reservoir is on the driver side.
There are two petcocks to open. The radiator petcock is on the driver side of the radiator, low. I removed the lower panel to access it but you may be able to reach it with it in place. The other petcock is on a hose right behind the radiator on passenger side. You can catch a view of it from below; the space is very small and I barely reached it with my fingers to loosen it. After filling up both reservoirs, I ran the engine to normal operating temperature, then opened the bleeder valve; it is right next to the oil dip stick.
As with all my vehicles, I flushed out the OEM coolant and switched to universal coolant, SuperTech this time around. At the next coolant flush, at 150K, I will replace the hoses and thermostat. Note: I did not spot a block drain valve. But, after draining the radiator, I filled the system with distilled water and, after bringing the water to normal operating temps, I drained it a second time.
Also did an ATF flush. Did a spirited test drive and car shifts normal; it has no leaks; and temp gauge stayed in the middle. Car has 99635 miles.

kkanchha

Thanks for sharing your experience. I looked for youtube videos for this model, couldn't find it but it is here.

kkanchha

Purchased two day TIS and solved my problem.