My car has an upgraded koyo rad, fan switch, alum ast, and i run a 70/30 mix...
> try to keep it at 190F w/ switch (more room incase hose blows or something to pull over before overheat) as stock tstat hits 210-220
>I always let the car cool to 182F before shutting it off...

>now on a hot day in ''bama, (100-103) I come back to the car and turn the key to acc and bam the temps are already at 240!...WTF how can it heatsoak that much? This is with hoodpopped...so i started the car with fans on and it dropped off almost instantly to 200..If the water heatsoaks to temperatures this high after shutdown, can it still cause damage to the water seals even if the engine is off? Is it best to turn the car back on and let it cool back down because it certainly will not cool down that quick with the engine off it just sits at 230-40 on some days for 15mins or so

 

Your water temp is always going to go up after shutdown. Trust me, I live in Las Vegas where ambient temps reach 115+. It's completely normal, as long as temps go down when you turn the car back on. Stagnant coolant always reads high on temp gauges.

 

My car does this sometimes, and I think it's got to do with two things:
1. Heat from the OEM (cast-iron) turbo manifold being transferred to the motor.
2. Oil temps might have been pretty high, and the cooling system is no longer compensating for that.


Try this: turn your AC/Heater **** to full heat a few seconds before you shut the car off. This will open the flap that covers the heater core, allowing the heater core to dissipate a bit more heat while the car is shut down. I haven't tried this often enough to know if it works for sure, but it's worth a try.

-s-

 

It's a PITA but this is what I do.

1. Pop the hood up, let it idle for 15 mins with the fan running, heater on full blast.
2. Shut it down and wait about 2 mins. and restart engine with fan on to get the coolant circulating again and let it idle for about a min.
3. shut it down and keep hood open until the engine is cool to touch before closing hood.

 

Just having 240 degree coolant when the car is off wont hurt it. Its when you have 240+ degree coolant and 900 degree explosions going off in the engine.

 

Why would you leave your car at idle for 15 minutes? Just stay off the gas for the last 5 mins of your drive and shut it off as you normally would.

Also see 115 F temps here in Tucson.

 

You guys are being way too paranoid. As long as your cooling system is healthy, you got nothing to worry about.

 

^^Ditto, hard to explain but water temps inside the cooling system vary greatly. The 200 degree f nobody wants to exceed is a water temp read by the guage after the radiator. Anybody got a guage that reads out of the motor, before the radiator?Probably not. You have different temps throuout the motor that at shutdown, go back to the basic laws of Physics. Heat rises, and temperature variations throuout the engine equalize. Hotter temp zones decline and cooler temp zones rise. It happens in every watercooled engine alive. As long as your water temps are normal while driving, quit worrying about the demons in the garage.

 

Or get an e-fan that runs while the car is off until its cooled down :-D

 

Yup. My heatsoak temperatures go from 110C back down to 85C in about 90 seconds when I start the car, even if the car remains stationary. This clearly indicates that the high heatsoak temperatures are localized and completely unrepresentative of the overall coolant temperature, which is probably pretty close to the pre shutdown temperature. No automobile cooling system is going to bring several gallons of 110C water to 85C in 90 seconds.

 

I would just get a set of fans that run even with the car off. Most new cars do that stock now. Its too bad that this one doesnt. I think i'm going to get a dual flexalite fan set up for mine with a thermostatic control. Then i can set it to come on at what ever temp i want. So yeah!

 

After you run your car, park in a dark place or unlighted garage, pop the hood up, take a look at the turbocharger and manifold areas and you will see them glowing red. Time it until the time the red glow is gone and then you'll understand.

Your gentle 5 min cooldown will help but not much especially if you do some vigorous activities with your car.

 

I have owned my car for close to 4 years and have never seen my turbos glow red after running hard. I had a 92 Talon turbo back in the day I got to glow red(for about 20 seconds) but it was after around 6 0-120mph runs. Sounds like you have a clogged cat or some other problem with your seven

The point is, don't drive like a dumbass for a few minutes of cooling before shutdown.
If you want to idle your car for 15 minutes everytime you shut it off, go ahead.

 

Hey, YMMV but 3 SCCA regional and a few more club championships with the car is not to shabby for a dumbass.

I've owned it since new and have put a little over 42,000 miles of mostly AutoX's and track events on it in 13 years before the engine finally gave out a few weeks ago. It's being resuscitated now and the precat is being replaced by a DP to lessen the heat. The car has exceeded my expectations since I figured it'll last 4-5 years due to the motorsports foolishness.

Your opinion is valued so there is no need to get chippy

 

I wasn't calling you a dumbass, I apologize if that what you thought.