S1 Elise – Head Outlet Coolant Leak Fix

While I was replacing the exhaust manifold and heat shielding I had a general look around where I was working, particularly those places that are otherwise impossible to see with everything in place.

The only thing I found was a possible slight water leak from the gasket between the engine head and the coolant outlet pipe. It was hard to tell for sure if it was leaking but there was a droplet of coolant just under the bottom bolt and at the edge closest to the exhaust manifold there was the kind of dry crusty deposits you tend to find building up at water leaks. I may not have been certain there was a leak but obviously no point ignoring it especially with the reputation the Rover K-Series has and it being so easy to access while the exhaust manifold was out of the way.


So to the job was simply to remove the water outlet pipe, clean up the mating faces and refit it with a new gasket. So the first thing was to drain some of the coolant. No need to drain the whole lot just enough so the water level in the engine was below the level of the outlet on the head.

It seemed to me the easiest place to drain and catch as much of the water as possible was from the hose that connects to the pipe that runs down the right sill.


This worked pretty well, hardly any spillage.


From above the engine I removed the two hoses form the outlet pipe..


Back underneath to unbolt the outlet pipe from the head. This could be done form above fairly easily too. It’s kinder to the paintwork not to be leaning on it while reaching over from above though.


Then unplugged the temperature sensor plugs and the outlet pipe could be removed.


This needs a clean up.


Starting with a large, fairly fine file to remove the old gasket and crustiness and flatten off the surface.


Then some sand paper placed on a flat surface and the mating face worked…


…until the surface is pretty flat and smooth.


A quick rummage through my K-Mini spares in the garage roof turned up a new gasket which was a result.


To make refitting a little easier I applied a little silicone sealant to stick the gasket to the outlet pipe and clamped it in the vice while I prepared the mating surface on the engine head…


…and cleaned up the bolt threads.


Another thin smear of silicone gasket sealant.


Then everything back as it started.


After reconnecting bottom the hose too, the coolant went back in the top. The coolant I drained out was perfectly clean so no reason not to reuse it. The good thing about doing this is that you know how much needs to go back in and if it’s not all going in then there must be an airlock somewhere.


Still unsure if there was a leak there before and if there was it could only have been small but what I do know is that there won’t be a leak now.