Flojo805

The fix was a replacement of the water pump.

seanl

I have a 2012 460 Sport (108K miles), and experienced the spiking temp gauge and dash warning while driving at 70mph on the freeway. But as soon as the warning went on, it quickly went off and the temp gauge dropped back to it's normal position. I was quickly able to exit the freeway and turn off the car. When I popped the hood, there was nothing out of the ordinary, no coolant smell, no coolant leaking, no hot smell, hood felt cool (ambient temp was around 60 degrees).

I started the car up, runs and sounds fine, so I continued my drive to the office where I immediately checked the Forum. So consensus is that it's either the thermostat, water pump, or valley plate..I will bring the car to my local indy repair shop hopefully tomorrow. Low coolant light has not turned on either.

HZakiH3

Were you able to find a solution? I have the same issue and have already tried replacing the thermostat. Seemed to have worked for a few weeks but now it’s doing it again.

There seems to be no rhyme or rhythm to it. Just randomly goes up and then comes back down fairly quickly.

Had a pressure test done as well and they found no leaks.

seanl

My issue was low coolant, as I haven't checked it or topped it off in several years. My local indy shop tells me that he tops off LS460 coolant at every oil change --but I've been changing my oil since I bought the car in 2016/17, so my bad. A bigger question is why would the car consume any coolant? The valley plate would see to be a likely culprit but there's no signs or smells of any coolant leaking.

I assume your coolant is full and stays full?

HZakiH3

yeah, should have mentioned I got a pressure test as well and they found no leaks.

swfla

iTrader: (1)

The coolant reservoir cap has a gasket/oring that can go bad. It is supposed to hold pressure. A new cap is inexpensive. Pressure test doesn't test the cap as it's removed to do the test. Once air gets into the system, it can create these symptoms. Just because you can't find a leak doesn't mean there isn't one. Take this opportunity to replace the coolant, it's probably overdue. The tech will purge all air out as well. It'd be great if we could talk through this to find a cause, but sometimes you just need to go hands on with a few inexpensive maintenance/repairs. Have you replaced the temp sensor? What if it's malfunctioning?

Protholl

I treat the radiator cap as a maintenance item on my vehicles. I replace them every 3 years. I also replace the gas cap every five years or so. It's cheap insurance. Oh... and always OEM.

lexo98

iTrader: (2)

If at some point the coolant runs low and you refill you can trap air in the system. The air traveling thru will mess with the fans and temp sensors. Depending how much air you can overheat. Look up burping the cooling system.