I’m an idiot. I broke the first rule of automotive diagnosis. I was a vocational teacher! I must have intoned a hundred times the key to profitable diagnosis:
“Always check the easiest thing first.”
I didn’t do that. I didn’t really check anything – I just jumped to a conclusion. See coolant dripping off the front of the oil pan, your engine must need a water pump. And maybe eight out of ten times that’s even true – but what if you’ve got a real blowout at the thermostat housing? Enough of a leak to cause coolant to pour down the front of the block without evaporating? What then, oh mighty ex dealership mechanic?
It didn’t cost me anything but time, so I shouldn’t bitch. But one day less than a week ago I opened the hood while the engine was good and hot and needing a drink and found steam hissing out of a blown-out thermostat housing gasket. I didn’t know there wasn’t a water pump problem until I fixed the thermostat gasket – but I knew there was a problem with the thermostat gasket or possibly a cracked housing.
So today I replaced the gasket. And since it might be a cracked housing and I wouldn’t be able to get to the auto parts store for another week, I replaced the housing. And the thermostat, since I was there. Turns out it was broken too, so good.
And the front of the engine is not leaking coolant now.