what engine have you on the 1800 it looks like it is on the coolant outlet elbow on the l series it is on the coolant elbow at the front right hand end of the cylinder head on the td4 it is in the metal part of the intake .you have to take the top part off and you need something like loctite to seal it back on and you will need new intake seals but do not go to LR for them they are dear