Thread: Coolant Leak

I have a 89 3.5 with about 180,000 mile on the clock. It has been running well and has been a good reliable weekend runabout for the 2 years I owned it.

Recently while driving it I noticed the temp gauge was high and steam from under the bonnet. after lifting the bonnet I noticed the steam appeared to be coming from the area of the thermostat.
I immediately stopped and then drove it home a few hours later when it was cold again.
I topped up the radiator with water, and restarted and ran it until it was quite hot but didnt seems to be overheating.
After various internet searches I have done a compression test but all cylinders read between 170 - 190 PSI. the doesnt appear to be any water in the oil.

After the compression test I checked and saw the coolant level was low again.. so I started to fill the radiator again.. about 7l later i noticed that it was running down the back of the engine and around the bell housing at quite a fast rate.
I can see water lying/running on top of the inlet manifold.. at the rear of the engine.
The heater hoses appear ok as far as I can tell.

Any suggestions on where to look?
Because the water flows out when i am filling the radiator is it safe to assume that the engine/block is ok as this is all pressurised and appears to be working ok?.. ie thermostat working correctly and top hose stays cold until thermostat opens?

Steel tube that runs under inlet manifold ..,. loose clamp, damaged hose, corroded tube??? Leaking inlet manifold gasket?