Coolant leak when shut down

[Tommyboy6880]

I walked out to my car after work to see a huge puddle of coolant, and it still dripping off the bottom of the engine some 3 hours after I last drove it. I topped up with water, eased the car home (engine temp was fine, car seemed to run normally)and tried to inspect. Fired it up and idled, looking for leaks. Wasn't leaking. Turn it off, starts dripping like crazy again. Appears to be coming from near thermostat, but hard to tell it was dark and only had a small flashlight. Is that normal for a bad thermostat to dump fluid when the car is shut off? Anyone experienced this before? What else could it be? I've got the 1.8 engine

Thanks

[87supraman]

Which engine?

Sent from my SCH-I645

[Tommyboy6880]

1.8, no cel,

[old guy]

It could be the J plug. It deteriorates internally. When the engine is running the cooling system pressurizes and seals the plug. When you turn the engine off the pressure reduces and the plug starts to leak.

[Tommyboy6880]

So I looked closer today and the leak is coming from a quarter inch hole in the top of the thermostat housing just behind the coolant line coming out of the top of the stat. What is that hole for? Did something pop out of it? And it does leak while running, just not till it's more pressurized. When I was checking yesterday, I hadn't given the system time to pressurize before turning it off.

[Luxus Panzer]

where is this J plug?

I want to have a look at mine. Easy swap ti o new one??

[old guy]

So I looked closer today and the leak is coming from a quarter inch hole in the top of the thermostat housing just behind the coolant line coming out of the top of the stat. What is that hole for? Did something pop out of it? And it does leak while running, just not till it's more pressurized. When I was checking yesterday, I hadn't given the system time to pressurize before turning it off.

I vaugely remember someone else reporting the same problem in the past year or so. They ended up replacing the thermostat/housing assembly.

where is this J plug?

I want to have a look at mine. Easy swap ti o new one??

It is a bit difficult to get to without removing a few components. The open hole is where the thermostat housing attaches. Use the thermostat replacement DIY for how to get there. Clicky click

[old guy]

Tommy,
I have been looking at numerous thermostat housing pics as well as a quick peek at mine in place. I don't see any ¼" holes in the area you described. take a look at where the two housing sections are secured by the silver colored bolts. Is it possible that the upper threaded portion on your housing has broken through, thus leaving an open hole? Looking down from the top it could appear as a ¼" open hole.

[Slowaudi908]

[IMG][/IMG]


Back when i bought the car each night it puked coolant. It was the thermostat and thermostat housing i paid 350$ to get it fixed.

[diagnosticator]

Even if the J plug is not leaking now, when the T-stat is replaced, replace the J plug also.

[Tommyboy6880]

Im Going to replace the stat, just wondering what that hole is. You can see it on the replacement part on ecs, i can't upload photos for some reason, maybe because I'm on an iPad. It's right beside the fitting on the right of the picture old guy put up. I wonder if it's part of the mould process and just a weak point. I wonder if I just fill it with superglue? What do you think?
Thanks for all the help.