Ok, so I'm wondering if the steampipe really lets out visible steam?

Reason I ask is because I'm out of town and I let my wife drive the Z28 for the week. She called this morning saying that 'steam' was coming out of the engine bay when she was parking at work. She looked under the hood and said the steam was coming up from the back of the engine (i.e. near the firewall). She's positive its steam, not smoke, and says there's no coolant under the car. As for overheating, unfortunately, the temp senor wiring is bad as I've replaced my sensor three times and I've never been able to get it to read. Given the problems with the temp sensor, just to be on the safe side, I installed a stand alone switch for one of the fans.

In any case, I've never noticed steam coming from that area, but it's all that I can think of - am I right in thinking this could be the cause or should I be worried that something else is going on? Thanks!

 

Not exactly. It allows any air, or water vapor (steam) that gets trapped in the back corners of the head coolant passages to flow out the back of the head, around the engine and into a vapor/liquid separator in the radiator. Once the air is vented, and the occasional steam bubble is vented, it flows liquid coolant. And no matter what is flowing in the pipe, it should not escape from the pipe or be visible. If the steam pipe gets a hole in it, it's going to **** coolant all over the place, just like a hole in one of the coolant hoses.

 

Thanks - that makes sense. Any guesses for the cause of the steam?

 

My guess is she drove through water and it got on the exhaust or the transmission and that's the steam.. ?

 

If the car his hot and the system is under pressure it is more like a geyser.

Friend of mine tried to run his steam vent to the radiator overflow once. After 2 miles there was no water in the engine and no cap on the overflow from the pressure.