dajohnson53
Lieutenant Commander
- Joined
- Apr 28, 2004
- Messages
- 1,627
Hi: Serviced the water pump in my 1974 Merc 110 this spring. It seemed to work fine - motor ran fine, steady coolish-luke warm stream from telltale, engine block warm but not hot to touch. Everything fine, right?
The old impeller was not broken or damaged in any way, just routine change.
But sometimes the engine will run same as above, but sometimes the tell tale stream sputters and steams, very low flow, hot water (caught some in a jar, measured it with meat thermometer and it was around 140 F), engine block is hot to touch - can't keep my hand on it for more than a few seconds.
This will come and go, it seems.
Just yesterday, I was running it and it did the hot water thing described above. I shut down the engine, then restarted - the tell tale was immediately full flow, warm (not hot), and the engine quickly cooled down.
Obviously, there is something in there that intermittently blocks the water passage somewhere. First thing I'll check is the intake - but after that, All I know how to do is drop the LU and check the main water tube.
Can someone give me some advice how to trouble shoot this? I do have a factory service manual.
The old impeller was not broken or damaged in any way, just routine change.
But sometimes the engine will run same as above, but sometimes the tell tale stream sputters and steams, very low flow, hot water (caught some in a jar, measured it with meat thermometer and it was around 140 F), engine block is hot to touch - can't keep my hand on it for more than a few seconds.
This will come and go, it seems.
Just yesterday, I was running it and it did the hot water thing described above. I shut down the engine, then restarted - the tell tale was immediately full flow, warm (not hot), and the engine quickly cooled down.
Obviously, there is something in there that intermittently blocks the water passage somewhere. First thing I'll check is the intake - but after that, All I know how to do is drop the LU and check the main water tube.
Can someone give me some advice how to trouble shoot this? I do have a factory service manual.