Hello everyone. 2001 Honda Civic LX 5-Speed cheers to a lil over 175K miles. This has been goin on for 2 months now I wasn't really worried about it but now gets my full attention. Coolant leaks from the thermostat housing mainly after my car sits 4 or more hours its not a bad leak just very little leaks out. I replaced the housing itself 3 weeks ago but coolant still leaks out. What should I have a look at in the morning?
Well, if it's never been changed, then the thermostat is 20 years old, and so is (presumably) the O-Ring that seals it. I've not changed one on a Honda, but I have changed the thermostat (when I flushed the radiator) on my 2008 Camry, earlier this year. I found that the O-Ring was ripped up a bit, eaten into, degraded.
Just get the thermostat and its O-Ring changed out, with an OEM replacement. It's one of those "do the simple and cheap things, first" kind of interventions.
One other thing: Because I don't know Hondas (other than my wife's 2013 Fit Sport), I'm going to ask this question? Was there a gasket of any kind on the thermostat housing? If there was, did you remove the old gasket and replace it with a new gasket?
Yes replaced it
MMJoe is correct, in all of this. Everything has to be re-inspected. Let me give you an example of has to be checked: On my Camry, when I replaced the thermostat, there's a small push buttonish mechanism that has to be placed at the noon position (front, top, center). The thermostat won't work correctly if its fitted in at any other point. Ditto for all the other components MMJoe points out, as well.
If you can't find the leak with an initial visual inspection, then perhaps it's time for a dye kit. Pour it in the radiator, drive the car for a bit, turn on the black light and don the yellow safety glasses. Following the dye will tell you where the leak's origin point happens to be.
And MMJoe's suggestion that the leak might have an origin point other than the thermostat and its housing should be adhered it . . . Just follow the dye, and you'll find the origin point, at the thermostat or some other place in the vehicle.
Will do
Check your work. Make sure:
- surfaces are smooth. no cracks in block
- thermostat installed in correct orientation
- gasket did not shift or pinch
- gasket notch is aligned properly
- housing torqued to spec.
- defective gasket.
I would also make sure the coolant is in fact coming from the thermostat, and not dripping onto it from somewhere else.
Alrigh I'll do that