Hi I have to keep topping up my coolant a lot at the moment.

There's no mayo in the oil cap or dip stick.

Any ideas what it could be or that I could check.

Thanks

What year is the car, and what engine type?

Welcome to the forum.

 

If you do not top it up is it going to minimum and then still lower. as in lose of coolant?

The engine is a 1.2, petrol 3 cylinder engine and the coolant just keeps going down and then the light comes on for it

Also it an 06 plate

Edited 2 October, 20169 yr by Reganp

Does the engine look like this (6-valve variant):

 

 

 

Or does it have a giveaway black plastic cover/airbox over the engine (similar to this Seat version) signifying that it's a 12-valve type:

 

 

Reason I ask is that if it's the latter you have a reasonable view from above of one of the likely leak venues, if the former, the battery box is blocking such a view.

It's the 12 v engine like the seat

OK, I'll just go out and grab a picture of ours that will hopefully show you where to look for traces of leakage.

 

Here you go. Looking down just between the cover on  the back of the nearside headlight and the battery box, vertically below the top radiator hose, is the radiator thermoswitch. Look for signs of wetness and/or coolant stains around this item. For reasons not clear to me, after about ten years these start to become a little loose against the plastic they seal to, and leak. A little tweak of tightening seems to fix it. 

 

Edited 2 October, 20169 yr by Wino

Okay thanks pal

See edit to my last post for piccie. Click on it for larger version.

Just had a look at the try was slightly damp. Ran it for 5 minutes then a drop of coolant. Never been so happy to see coolant lol

Access/room to tighten is a bit awkward, whether from above or below, but I would recommend a 29mm deep socket (the one I bought was only just deep enough, can measure it tomorrow if you like). The electrical connector has to come off first, with the normal latch to be defeated, which may be awkward too, depending on which way it is oriented. 

If you have a torque wrench, 35Nm is the book number.

Thanks for the help and advice. If you could measure it would be a big help

OK. Overall about 80mm:

 

But that's not the important dimension.  You need the internal length to be at least (preferably a little more) than this one:

 

 

 

 

 

The reason you need that 38.5mm+ is that he connector part of the thermoswitch is quite long:

 

In fact this socket is only just engaging enough:

 

 

Edited 22 May, 20188 yr by Wino
fixed pics

So it's 1 1/8" AF then, plumbing and pipe fittings are commonly imperial sizes.