Help...Weird Coolant Leak

[transatlantic0207]

So when I fill up the expansion tank to the line, drive around a bit, then stop....coolant leaks from this spot near the engine speed sensor....I've posted pictures, can someone please tell me where and what am I looking at and what needs to be replaced? The pictures are of where I think I've traced the leak to, like I said its around the engine speed sensor.
btw...its fresh coolant that being leaked and i'll take more pics if needed

[ansonivan]

The water pump is a likely candidate since it's located above the area pictured, either the gasket is leaking (unlikely) or the seal is leaking.

[transatlantic0207]

hmmm water pump...how would I know if its the water pump?

[ansonivan]

Visually inspect the thing for leaks, its a tricky to get a clear look at the pump, best bet is by getting under the car. If you have access to a pressure tester that's a nice fast way to find the leak.

Changing the water pump on an m20 gets you 90% of the way to changing the timing belt/belt tensioner, if the belt is old then this is a good time to do that as well.

[transatlantic0207]

yeah I am kicking myself, I changed the timing belt in october but neglected to change the water pump.....I pressure tested it on saturday and there was no leak....it only seems to leak when I fill it up...when the expansion tank is about 1/3-1/2 full it doesn't leak

[Farbin Kaiber]

That does not make sense.

[transatlantic0207]

you're telling me....I was expecting it to leak but it didn't....it only seems to leak after driving a bit...i can idle for hours and it wont leak

[Manya]

water pump.
I did the same thing, timming belt but left the water pump. After a bit of kicking myself, it only took me 40min - 1 hour to change it without removing the timming belt.

Cheers

[xLibelle]

You use the old coolant tubes? The one off the top of hte pump could be the problem, letting coolant run to the block and only look like its the waterpump seal.

[transatlantic0207]

interesting....i'll get on it tomorrow and update

[a_thomasmr23]

how the hell did you do that gasket without removing the t-belt i just try doing that and it was a no go. I think you really almost have to take off at least the tension pulley.