Is it bad to cool the turbo with my garden hose after my half hour commute? I've been spraying a light stream over the oil line, O2 sensor and the little gap in the heat shield covering the exhaust manifold. My paranoia started after reading about failing journal bearings due to the coked oil from the heat soak. My buddy thinks I'm weakening the cast iron and aluminum. I bet the Metalman would know....
Well, using a water hose to cool your turbo down is not a good idea..... The bearing is water cooled by a separate pump that runs for a period of time after the engine is shut down. This is done to keep the bearing from coaking the oil after the engine is shut down and the oil is no longer flowing. Spraying water on a hot turbo will increase your risk of cracking or warping the twin scroll turbo housing or the cast exhaust manifold. I seem to recall that MINI made a software change that increased the run time of the turbo water pump after the engine is shut down..... They also came out with three versions of a clip-on oil line shield, with the latest having a flap of high temp material that better protects the narrow oil line from heat..... I suspect they discovered that high temperature air was being directed by the turbo heat shield towards the oil line. Strict use of a good quality 100% synthetic oil in your turbo MINI resists oil coaking.... Here is the oil line shield that should be used... It took MINI three designs to get it right, but the flap is the part that shields the oil line from the heat coming of the scroll.
Honestly, I would think that repeatedly cooling any piece of hot metal with water would increase the likelihood of that metal becoming brittle. Me, I just sit in the car with the engine running for about 30 seconds after a drive and let things cool off before shutting off the car. If you're really paranoid, you could pop the hood and blow a fan over it.
I kept a box fan in the garage right in front of the grill and left it running. Come home, park in front of fan and pop hood. Also, you can get a device called a turbo timer. It wires into the ignition and presets a run time after you turn off the car. Engine continues to run for x minutes and you can lock car and take key. Timer will shut off motor. Allows the pump to continue to cool down the turbo.
If you read Metalman's post, there is absolutely no reason to do that, it has a factory pump that runs after you shut off the engine. About the only time you might want to let it run for 30 sec or a minute is if you come off a hot track run and straight to the pits, for street driving there's no need. Don't forget, the turbo is water cooled already, from the factory so it doesn't get THAT hot.
Are you driving that aggressively on your 30 min commute? You should be fine after that, even if you are going balls to the wall for part of your drive. But for for ****s sake, STOP RUNNING COLD WATER ON THE TURBO HOUSING!!!! Thats going to be way way worse for your turbo than it getting a little hot from time to time. Just pop your hood, or like mentioned above buy a turbo timer.
Ok, ok got it. I do pop the hood every night and I do have that Mickey Mouse shield over the oil line too. I don't know why I worry so much since it runs perfectly and never had a problem with it. Research is a double edged sword. Kinda like webMD. Thanks guys.
Consider connecting a turbo timer to your water hose and direct the water only at the oil line........ That will give you a water cooled turbo bearing that's water cooled.... I keed.....