melymel96

So for the past couple months every time I get on this incline on a freeway transition my temperate gauge spikes to red and the notification center tells me the car is overheating and to pull over a couple seconds later it goes back to normal. This has happened about 7 times now over the past couple months. Anybody have any ideas??

07 LS460 just hit 80K miles. Keep my car in very good shape. This is the only problem I've had with the car.

CJITTY

Bad thermo?

G-SharK

Agree with Cjitty

marylandlp

The first thing you have to determine before anyone can give you any meaningful advice is whether the engine is really overheating or is it a gauge/sensor problem.Take a look at your coolant level to see whether you've lost any coolant and also look for coolant overflow on the street when the overtemp gauge indicates an overtemp condition.Also,when it overtemps again,open the hood and carefully look into the coolant tank for steam or bubbling,both of which are indicative of an overtemp condition..

Lextrician

coolant temp switch giving false reading but you do have to really determine if it is. take it to a radiator shop and you should be able to find out.

melymel96

Thanks guys I'm going to take it in and have it looked at. I live about 5 minutes from the spot it always does it at and when I got home I popped the hood and from what I can tell the heat coming from the engine bay was normal. I'll keep you posted.

SC400slide

iTrader: (11)

That happened to our 2001 Sequoia. The thermostat is on it's way out. It's not too hard to replace.

jgbackes

iTrader: (2)

I vote for a sticky thermostat.

FLYCT

If it were my 80k mile, 2007 car I would have thermostat AND hoses replaced.

A soft hose on the suction side can partially collapse and cause the same symptom.

I8ABMR

Sounds like its absolutely the thermostat if the car is not over heating. Get it checked.

marylandlp

What did the dealer find?

powermar

I'm having this exact same problem, and while OP didn't deliver on his promise, hopefully someone else with this issue can help.

While it might be the thermo, the needle stays dead steady in the middle 99.9% of the time. Then when I go uphill it spikes up to the max within 2-3 seconds and I get the dash alarm. Then after a few seconds, it drops back down to normal, again within 2-3 seconds, and stays there for a long while (hours). I wouldn't think there is anything the thermo could do to change the temperature that rapidly, so I was suspecting the sensor or the gauge.

Of course I'm taking it into the dealer later today or tomorrow, but just wanted to see if anyone else had the solution. With it happening so infrequently, I'm worried the dealer may not be able to make a diagnosis.

sktn77a

iTrader: (2)

Could be a sticking thermostat (most likely, based on OP's description) but could also be air in the cooling system or (least likely) a problem with the coolant tenperature sensor. If either of the former, your car IS overheating, albeit briefly, if it's the latter, no harm done.

But being as this is a Lexus LS460, the most expensive Lexus in the world, and could blow your wallet clean out, you gotta ask yourself a question...... "Do I feel lucky"....... Well, do ya punk?

LXurious

Had this issue occur ONCE and one time only, out of the blue it says engine overheat and showered the red thermostat, I immmediately pull over and the car is fine. I reluctantly drove home in the slow lane for a while then gassed it for a while and nothing has ever came up since. A bit strange but only once

roadfrog

Classic symptoms of a failing thermostat.