Water top up
 

My 1.8t has needed topping up with about half a pint of antifreeze about every 100 miles. The headgasket was done about eighteen months ago. Could there be any other reason than the head for this leakage? I can't see any obvious leaks. Would welcome opinions.

Possibly inlet manifold gasket. Leaks when the engine cools down allowing a little coolant into the cylinders which burns off once the engine starts. The leak itself seals once everything warms up and expands. Is there any evidence of a misfire on start up or steam from the exhaust which disappears after a minute or so. Check the spark plugs as well, if one (or more) is exceptionally clean its evidence of any leaked coolant burning off, effectively steam cleaning the plug.

check the cap on the expansion tank first. the rubber/ plastic sealing rings can get aged quickly and allow coolant to overflow. new cap from German supplier stopped my problem for £ 12.00. second check for signs of dried coolant around all water pipes especially near jubilee clips that get over tightened.

Water top up
 

The manifold gasket was replaced when the head was done and I've replaced the radiator cap!

Could still leak though. Check the fixings are tight.---:}

OK. How much coolant are you putting in the tank? The max level is right at the bottom of the tank and any excess will be ejected.

Next, is it the original plastic manifold because they can become distorted.

Yes filling above the bottom of the fins will get expelled till it gets to that level ( my first mistake on getting my ztt ) it feels strange at first leaving it looking so low but if there are no leaks it will stay that way . worth checking that when the head was done the system was bled to remove air ,which can also blow excess out and then leave the system short.

That’s a lot to lose! Have a look at the metal pipe that runs around the rear of the block, and the plastic thermostat housing at the end of it, both of those are known for leaking.

Water top up
 

Thanks everyone for the advice. Will try to narrow down. Wish you lived near Tricky!!

Ah yes those were the days when he was in Barton:duh: