Can someone please help me figure this out.... So last night I was sitting in McDonald's long *** drive thru line waiting to pick up some door dash order and I noticed temp hand rising on my car (2003 LS430) so this morning I put coolant (50/50) in there and my car is still running hot 🔥 I'm a female and as some men say that us females dont know about cars... Can you guys please help a sista out

 

Your car has cooling fans in front of the radiator which are supposed to help keep the engine cool in situations where you are parked or going real slow, like you mentioned. Did you hear them come on? If they are not coming on that might be part of your problem. If the car is NOT over heating when you are driving down the road at normal speeds that would further indicate the fans as a possible problem. If your car is overheating all the time, even driving down the road, you are probably still low on coolant or your water pump is going bad. You should also look around closely for where you are loosing coolant. I would recommend you get this issue resolved right away before serious engine damage happens.

 

I had a similar situation on my previous LS430 and it turns out the radiator went bad. Inspect it carefully for coolant leaks, blockage (leaves), etc. I'd also avoid driving it hot to avoid serious engine damage.

 

There are a few things to check:
1. As mentioned low coolant is a big thing to check. I've seen my LS 430 down nearly a quart and the gauge was alright. My fault for not checking. I don't think it had been checked for several years.
2. As mentioned check the fans. If the motor is hot and idling the fans (2 of them) should be on. If they are both off check the fuse. If they are simply not working, purchase a new assembly (get a used one off of e-bay). Sometimes it is a bad motor, but I wouldn't waste my time. Get a used one, the new ones are just too much money. Pretty easy to replace the assembly.
3. May be the thermostat, but this is rare.
4. Head gasket is also rare, pray this is not the case.

Remember, if the gauge reads high, do not drive the car until the temperature returns to normal. These cars have super good cooling systems, so if the gauge reads high get it fixed ASAP.

Loren

 

Since you had to top-off the radiator, check the coolant level in overflow reservoir (to your left). If that had gone dry before the top-off, there must be air in the cooling system.

First, fill the reservoir to a level around half (between Low and Full) and close with reservoir cap.
Second, you will need a tall funnel (make sure it is at least 8-10 inches tall) with a neck that will just fit the radiator opening and some rags
Third,
- make sure the car is completely cool
- start the car and turn-on the heater and set it to high
- open the radiator cap and insert the funnel, put rags at the joint, and make sure it will stay steady when the car is running, or hold the funnel by hand
- watch the funnel for 20-30 minutes, the bubbles will indicate if there is air in the system
- air bubbles and coolant will start filling up the funnel
- continue to watch until all the bubbles are out

Finally,
- if needed, top-off the radiator again
- put the radiator cap back
- clean up any coolant spillage
- shutdown the car, let the car cool down.
- take it for a short drive and monitor the temperature gauge

Of course, check the coolant levels before every drive for several days for any leaks.
And, like others have said, get this fixed soon.

 

Good writeup on how to burp any air bubbles out of the cooling system.

Remember: NEVER open the radiator cap when the engine is warm/hot. You WILL hurt yourself.

 

Okay I did something like that yesterday….. didn’t use the funnel

I didn’t drive all day yesterday but when it was time to drop my daughter off to her dads….before I started the car I took the radiator cap off and some liquid splashed out but mind you the car was cool because I didn’t drive it anywhere until it was time to and which the gauge didn’t raise passed the middle when I started it

So today when I started the car the gauge didn’t pass the middle line so Am I in the clear or still go get it check out

 

Keep an eye on it, maybe go to another long *** McDonald's drive thru line (or you can let the car sit idle after you've warmed it up with driving).

• If your temp gauge doesn't rise out of wack, you should be fine. The system probably just needed some burping.
• If your temp gauge rises while driving (i.e., air is moving through the radiator), then you have a bigger issue. (Stuck thermostat? Failing waterpump? Engine is "truly" overheating?) Take it to a mechanic.
• If your temp gauge rises while idling:
  • a) If you hear your radiator fans turn on... then maybe the system needs burped again.
  • b) If you don't hear your radiator fans turn on... then something is amiss with the thermostat/switch for the radiator fans.

Good luck!

 

Before driving each day, check the coolant levels in radiator and reservoir for several days and monitor the temperature gauge. Also, check the dip stick for oil level. If oil level is towards low, get an oil change immediately and monitor that for several days. It is an ongoing process.

 

not sure if your car actually overheated or not. My temperature usually stays at the middle and never moved.

 

Surprise, surprise. since my own posted a couple weeks ago, I am in the same boat - My LS430 was overheated today in traffic.
Temp went all the way passed H. Pulled car to the side and let it cool a bit. Able to made it to my inlaws house.
Anyway, issue seems to be both fans are not on based on some quick observations. Car is parked but I will take it home tonight (want to avoid traffic)

1. how to check the fuses on the fans since I am not sure where I put my owner's manual.
2. "Will both fans turn on when AC is on?" or fans only turn on once engine passed certain temperature.
3. What other things I can check other than coolant level?.
4. FYI - my car was at Lexus for timing belt last week and I have been driving it everyday without issue until today. I don't think it has anything to do with water pump/ thermostat

 

Check the oil level, too. After the TB/WP job, accessory (serpentine) belt could also be suspect (guessing).
From the 2002 Owner's Manual
Fuse #74 (7.5amp): Electric cooling fan, Headlight cleaner, Charging system, Starting system, Rear window defogger

 

Just a thought here but having the timing belt done last week and now this is happening is is a very big coincidence. I am assuming the procedure also included the water pump and thermostat as that is highly recommended at the same time and most kits you buy have it all in one package. When water pump is removed the coolant is also. It is not easy to get all the air out of the system and it could be air is now trapped where the sensor for the fans are. Also check the connector on fans for broken wire. May not be related but if it were me I would assume it is something related to the procedure until proven different. Call them and see what they say.

 

Mine was doing this 3 months ago. Turns out it was the backing plate leak (coolant leak). There's a video of it on YouTube from a UCF30 guru in New Zealand. I've had this happen twice, actually, though the second time the temperature gauge actually started rising in idle or if I was sitting in a drive thru etc. First time I never even noticed it, it was just picked up in a general service.

Cost to fix this issue was around $350 AUD, translating to about $230 USD. They had to reseal the plate with silicone and drain and refill the coolant.

I've linked the video

 

Root caused my overheating problem.
anyway, issue was due to #4. during the timing belt replacement, they unplugged the fan and tucked the wire on the driver side. The dealer took care of it and topped of coolant. All good.