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My wife’s g37 just starting pouring out coolant about two weeks ago as she was picking up the kids from school. Long story short, I got it fixed, it was a coupler for the heater core underneath the air intake, was a three inch long piece of tube that fought me to death. Filled and tested. Everything was great for a week and a half. Just noticed a hissing sound today, coolant dripping on the floor, heater core dry so no hot air, managed to get the kids home, by constantly stopping and shutting it down to let it cool, dropping into neutral as much as I could and even coasted unpowered in neutral a couple times, fun stuff.
Looks like the leak is dripping on something hot now (hissing and steam) inspected visible locations and okay. Looks to be coming from under the plenum now. Thoughts? I’m wondering if my wife ran it too hot and blew things out. Iv replaced the lower hose at the same time as the tstat, and the coupling, that’s all so far. Could use the assist on this one, as we are down a car. I have a video that may or may not help.
Looked like it was coming off the backend of the main engine coolant pipe that runs through the center on top of the block next to the heads. I am going to replace the hose, and pressurize the system to check for additional leaks. That specific hose passes coolant to the throttle body, which I was unaware of functionally.
I am getting to the point of wondering if I need to just start replacing hoses to be on the safe side, the age of most of these hoses is over 10 years and going on 150k miles. A little preventative maintenance perhaps. So far my plan is to replace the two hoses, replace the intake manifold gaskets, clean the manifold, inspect, clean, and flow test the fuel injectors, clean the plenum, and replace her torn air intakes with some silicone units. Noticed some leaking on her valve cover as well, so may swap the gaskets since I’m down here. New valve seals and springs also isn’t a horrible idea, but I’d likely need to take it to a machine shop so might avoid at this time.
Unless you are having engine issues that point to the valves, I would leave the valve train alone. Things get VERY complicated with the VVEL system. Just my 10¢.
Last edited by ILM-NC G37S; 05-29-2023 at 04:31 PM.
Unless you are having engine issues that point to the valves, I would leave the valve train alone. Things get VERY complicated with the VVEL system. Just my 10¢.
gotcha, makes sense to me. The vehicle being down is rough on the family, so I was going to attempt at making the most of the time it’s apart. I don’t normally fix things that aren’t broken as iv learned, but overheating issues back to back doesn’t leave me with peace of mind.
05-28-2023, 07:24 PM
