So my SC is overheating and I'm still deployed..Awesome.
 

Hey guys,

So I got some awesome news from the wife on our "voice chat night" this week..

Apparently she was in traffic and the SC started running hot while stopped. She told me that it stayed cool while rolling, and the temperature only rose while sitting. Most of her driving during the week is highway driving, so this is the first time she noticed it overheating. The SC has performed perfectly up until this problem.

I asked her if she heard / saw the fan operating, and she told me that the sc "sounds like a jet turbine engine, is that the fan?" (I repair aircraft engines :p)

Coolant tank is full of coolant as I had her check.

The car is being taken in tomorrow to get looked at, I already looked up the water pump/timing belt DIY and would much rather do that task myself so that I know it's done right...

Though this is my 2nd deployment, it still sucks that I am not home to fix my own car :egads:

Do I have any chance that the radiator just needs a flush or the thermostat is stuck? Could a bad cooling tank cap cause this symptom? From prior experience, I find that few water pumps are actually the cause of overheating issues, but this is my first lexus.

Thanks for reading CL, if it's TLDR, just read the bold text.


*UPDATED* 02 June 2013

So my wife dropped the car with AERSI, an independent Toyota/Lexus only shop. Turns out there was a very small coolant hose that was cracked, and another small hose that had come loose was leaking my coolant out (how my wife never got any puddles is beyond me). The diagnostic was 78.00 and included the replacement hoses and refill of coolant. They also added some dye and invited her back to check for leaks (free of course) next week.

They also humored me and inspected the fan system. They informed me that they were functioning correctly, and the car was well maintained for the majority.

Glad to have the SC back on the road even though I am not home to drive/enjoy it.

Our Sequoia had a sticking thermostat. When sitting in one place, not even for very long, it would come close to overheating. Replaced thermo with new gasket and hasn't had a prob since. I'd venture to say that it's your thermo, at least, start with that. Maybe your wife can replace that herself? lol

The hoses could be clogged

I'll keep my fingers crossed. Thanks.

Well, my wife took the sc to a nearby shop....utter fail >.<
Supposedly, the tech could not replicate the problem, but would not check the radiator for clogs or pressure test the system for leaks. He told her that this car had "a very complicated engine" and also said just to "put the car in neutral in traffic"...what the F???

After this, he gave her a card for another shop >.> srsly?
A guy that worked on my lexus before said he would do as I asked and check a few things before I think about ordering any parts.

What a crappy day @.o

Could be the fan not sure you have aftermarket fans but on my 1st SC it had electric fans rigged up by the previous owner and had the same problem once. Turns out one of the wires came lose. It also could be a thermostat like suggested or a leak in one of the hoses or the radiator. Hope it works out for you man.

Factory fans. Got a guy that's gonna go over the radiator and hoses tomorrow.

pull the thermostat, takes about 3 minutes to do. mine went bad at a hundred and fifteen thousand miles, pulled it out and no problems overheating since.

bet you that's it...

The fluid fan has never ran low or clogged on me, but the diaphragm could be failing. In traffic suggests the fan is not turning properly. I'd check the tank anyway to see what level the fluid is at. It's just ATF fluid I think.

I also seem to think that is the thermostat. I say replace it, replace with fresh coolant and go from there.

Is the 1uz sensitive to coolant type or can I run green as long as it's all one type of coolant?

I'll order a tstat from rockauto and nab a new pair of hoses + cap while I'm at it.

I'll keep you guys posted. Thanks CL

interested to see what the fix is. I just had the same issue start with my other car today. in the drive through tem crept up to the red line and the fans did sound like they were trying to make the car fly. started driving and doewn the temp went

I had this happen to my 94 sc400 a few years ago. On the hwy it was fine but as soon as traffic slowed down it would start overheating. Replaced the thermostat and it was fine.

you could just go without the t-stat all together, I live in South Florida fine for me