I replaced the coolant tower a few months ago with the aluminum casting.

I've had problems with sealing at the thermostat housing, on removal it looks like the coolant was flowing through the paper gasket. Bolts were tight.

The top cap of the tower also refuses to seal, even after I put RTV on it. The casting is quite rough so I might try the plastic cap.

Yesterday I also pulled the upper manifold to check the condition of the valley hoses and look for other leaks. Anything else to check while I have it off?

Any tips for getting the gasket/cap to seal? Is there a specific kind of RTV to use?

2000 XK8 Coupe. Thanks,

edit: Looks like maybe the paper gasket that came with my kit is incorrect.

NCA2269CA ribbed gasket at base of tower
NCS2246BA seal that goes around thermostat

 

The thermostat has a split 'O' ring around it. The paper gasket is not used.

There have been reports of poorly cast thermostat towers, some returned.

There is an 'O' ring seal for the cap also. No RTV should be needed either place.

 

Thanks- that would explain why it looked like the paper gasket was allowing coolant to seep through!

I also turned up trying to use the plastic cap with the metal tower.

 

While you have the intake off, the knock sensors could stand a cleaning on the bottom and around the stud or bolt, as a leak at the front runs down in that area and corrosion builds on the little pedestal where they sit.


Wayne

 

also look at cap hex bolts for the 2 rear bolts for the tower or cut slots in the bolts on top for a screw driver to make removal of said bolts easier in the future if necessary .