slydog75
Petty Officer 3rd Class
- Joined
- Jun 15, 2009
- Messages
- 90
I have a pretty good coolant leak (about half gallon per hour of runtime) on my 1987 165hp Mercruiser 470. I don't believe it's the camshaft seal as both the seal and the camshaft itself were replaced appx. 20 hours ago. The coolant is pooling in the bilge when running on the water, however there is no leaking at idle, when testing the boat out of the water. The oil appears fine when I test it on the dipstick (not milky at all). It doesn't overheat at all as long as it doesn't run out of coolant. In fact it runs rather cool even when pressing it pretty hard, barely passing 160F or so. The only way I know it's draining out is from the coolant in the bilge and the empty reservoir. Also, the coolant is not being sucked out of the coolant overflow bottle like it should be as it's always full (in my understanding the coolant reservoir shouldnt' be able to empty out without sucking the overflow bottle dry first).
The previous owner did a partial rebuild on it and it's been leaking ever since (a couple of months). He suspects it's the exhaust gasket, but I wanted to get some more opinions before I start tearing it apart. Could this be the head gasket? Would it be pooling in the bilge if it was? I'm trying to track down a pressure tester to see if can help me find the leak and I'll post here with those results if I find one soon.
The previous owner did a partial rebuild on it and it's been leaking ever since (a couple of months). He suspects it's the exhaust gasket, but I wanted to get some more opinions before I start tearing it apart. Could this be the head gasket? Would it be pooling in the bilge if it was? I'm trying to track down a pressure tester to see if can help me find the leak and I'll post here with those results if I find one soon.
