High Temp / Maybe overheating? 2015 LX570

[LXGus]

Wondering if anyone has had this issue. I don't typically look at my temp gauge much, but today, after an oil change, I ran errands and randomly glanced at my gauge. It was at red and moving towards the H. It stayed for 10-20 seconds and dropped back to normal. Another few minutes it did the same. I watched it throughout the day and it kept doing it every so often. Is this normal? Did I do something harmful during my oil change? Is it something else?

 

[bloc]

What have you done so far to investigate? Full of coolant even?

 

[LXGus]

What have you done so far to investigate? Full of coolant even?

I started this thread - because I just noticed the issue and was wondering if it's normal before I start investigating.

 

[bloc]

I started this thread - because I just noticed the issue and was wondering if it's normal before I start investigating.

It's definitely not normal.

 

[TomEf]

Sounds like you're either low on coolant or have a bubble, especially if it fluctuates based on idle/having throttle input.

 

[doru]

Are you loosing coolant, any leaks? Check level.
It is not normal and I'd avoid driving it until troubleshooting. It it turns out to be a problem it can become a very expensive one if you overheat the engine.

 

[Sandroad]

Just changing the oil you could not have done anything to cause the fluctuation. I’ll bet it’s low on coolant and you’ll need to find the cause. Don’t drive it until it’s cool and you’ve checked/added coolant.

 

[TeCKis300]

Perhaps first troubleshooting step is to look at the radiator coolant reservoir (white tank mounted to radiator). Is there any coolant in there? From the symptoms, it does sound like there is a bubble or fluid is low.

Then the more difficult part is why? As coolant doesn't just disappear.

 

[LXGus]

Just changing the oil you could not have done anything to cause the fluctuation. I’ll bet it’s low on coolant and you’ll need to find the cause. Don’t drive it until it’s cool and you’ve checked/added coolant.

You’re right. Let it sit over night and checked it. It’s very low. Should be fun to figure out where it’s leaking. I’ve also read a few posts about an replacement radiator cap with an overflow - does anyone have a picture or link to one?

 

[liv2bike]

Pop the hood and look for any visible signs of pink residue. Get under your truck and do the same with a flashlight.

 

[bloc]

This would be my prime focus if the radiator isn't cracked.

Kind of "Mystery" Coolant leak back of engine (heat exchanger valley leak)

Hey guys, I had another thread going on on my 09 Lx puking out coolant from what I thought was the waterpump.. But after taking wheels off and a bunch of other plastic crap off of the front of engine (more than I want to remember) waterpump area is completely dry and is coolant drip free (no...

forum.ih8mud.com

 

[LXGus]

Pop the hood and look for any visible signs of pink residue. Get under your truck and do the same with a flashlight.

Topped the tank off and looked everywhere. Spent a good 30 minutes underneath and didn’t find anything. I’ll monitor the level and if it drops again soon I’ll follow up in here.

 

[gaijin]

Topped the tank off and looked everywhere. Spent a good 30 minutes underneath and didn’t find anything. I’ll monitor the level and if it drops again soon I’ll follow up in here.

Just a reminder - the coolant (Toyota SLLC (Super Long Life Coolant)) should be at the full mark on the overflow reservoir when the engine is cold.

HTH

 

[Sandroad]

Topped the tank off and looked everywhere. Spent a good 30 minutes underneath and didn’t find anything. I’ll monitor the level and if it drops again soon I’ll follow up in here.

Did you also look in the radiator by removing the cap when cold?

And I’m not sure what you mean by a replacement radiator cap with an overflow?

 

[LXGus]

Did you also look in the radiator by removing the cap when cold?

And I’m not sure what you mean by a replacement radiator cap with an overflow?

I didn’t look in the radiator. What would I be looking for?

I had the same question regarding the cap with an overflow. I saw another thread and someone was throwing shade at the person posting who didn’t replace the stock radiator cap with a new one with an overflow

 

[marques]

This is most definitely not normal and could result in $$$$$ repairs. Looking at the fluid level in the overflow/expansion tank doesn't tell you how much coolant is in the radiator. It just tells you how much coolant is in the overflow tank. If the overflow tank is empty, you will need to remove the radiator cap (after the engine cools down) and look in there to see if there is any fluid visible. It should be filled all the way to the top. If not, fill it all the way to the top (in the radiator, not the expansion tank) with the 50/50 pre-diluted Toyota pink coolant. Take your time and check the level every few minutes as it could be dropping slowly as coolant finds its way into the engine.

Once the level seems to be holding steady after a few minutes, start the engine and let it idle with the front/back AC in max temperature and max fan. speed. Keep an eye on the fluid level in the radiator and keep adding if it drops. It's typical for the fluid to slowly drop as air bubbles come out. Or it could drop suddenly when the thermostat opens or if it burps a big bubble. You can massage the upper radiator hose to help get rid of air bubbles. Keep topping it off until the level holds steady and completely full to the top. Then put the radiator cap back on, and add coolant to the expansion tank all the way to the Full mark.

Only then (once you verify the radiator/engine are full of coolant) would it be safe to drive the truck without risking a very expensive overheat. Find the leak and fix it. You should see some pink crud wherever it has been leaking.

The radiator cap is just a regular cap. It doesn't have any kind of "overflow". The overflow port is built into the radiator neck where the cap goes. A hose goes from there to the bottom of the expansion tank. And the cap for the expansion tank has another small hose that just dumps any actual overflow into the ground.

 

[yOHda]

I wouldn’t just top off and go. I would buy a burp kit and make 100% sure there are no bubbles. I’d also do what @marques suggest. Though I would run the heat at full blast as the vehicle is coming up to temp vs the a/c.

 

[bloc]

This is most definitely not normal and could result in $$$$$ repairs. Looking at the fluid level in the overflow/expansion tank doesn't tell you how much coolant is in the radiator. It just tells you how much coolant is in the overflow tank. If the overflow tank is empty, you will need to remove the radiator cap (after the engine cools down) and look in there to see if there is any fluid visible. It should be filled all the way to the top. If not, fill it all the way to the top (in the radiator, not the expansion tank) with the 50/50 pre-diluted Toyota pink coolant. Take your time and check the level every few minutes as it could be dropping slowly as coolant finds its way into the engine.

Once the level seems to be holding steady after a few minutes, start the engine and let it idle with the front/back AC in max temperature and max fan. speed. Keep an eye on the fluid level in the radiator and keep adding if it drops. It's typical for the fluid to slowly drop as air bubbles come out. Or it could drop suddenly when the thermostat opens or if it burps a big bubble. You can massage the upper radiator hose to help get rid of air bubbles. Keep topping it off until the level holds steady and completely full to the top. Then put the radiator cap back on, and add coolant to the expansion tank all the way to the Full mark.

Only then (once you verify the radiator/engine are full of coolant) would it be safe to drive the truck without risking a very expensive overheat. Find the leak and fix it. You should see some pink crud wherever it has been leaking.

The radiator cap is just a regular cap. It doesn't have any kind of "overflow". The overflow port is built into the radiator neck where the cap goes. A hose goes from there to the bottom of the expansion tank. And the cap for the expansion tank has another small hose that just dumps any actual overflow into the ground.

This is a great post, thanks for taking the time.

The only thing I’d add is parking the front of the truck a little uphill can help any air find its way to the radiator cap area.

 

[LXGus]

This is a great post, thanks for taking the time.

The only thing I’d add is parking the front of the truck a little uphill can help any air find its way to the radiator cap area.

Agreed! All great info! Thanks for taking the time Marques to hit all the details.