loosing coolant?? why??

[Ciaran 4]

lost water in the coolant gradually over the last 2000 miles.

its only gone from the max mark to slightly under the min is this something to worry about or am i being daft???

no mayonaise under the oil cap and no noticible leaks??

also is it ok to top it up with normal straight water??

also the car has done 87k and is driven reasonably hard at times.

[Seademon 0]

You might have a loose hose or the coolant could be coming out of the headgasket and running down the the side of the block - when a headgasket goes, the water doesnt always mix with the oil. Best bet is to get it up on a ramp and see if theres any signs of where the water could be leaking from & also do a compression test - that way you can tell if its your headgasket or not

[francisjonno 2]

As Seademon said, get it on ramps and check for leaks. It could be the themostat housing or water pump, amoungst others...also check the coolant resevoir - it could be cracked or coming out of the reservoir overflow valve

[Geastb 0]

Mine was losing coolant from thermostat housing, fixed that then found it was still losing a little coolant (about a pint in 500 miles) trurned out to be the expansion tank cap leaking - fitted a new cap (about

[Ciaran 4]

does the expansion tank lid need to be stupidly tight to not leak?? cos the level has only gone down since i removed he cap for the first time since getting the car.

when i removed it then it was so tight i had to use a set of mole grips. when i retightened it i only hand tightened it a slight bit!!

[Nerih 0]

yep mine did the same, i dont do it tight anymore, screw losing a few pints through the cap, at least this way i can undo it!

check hoses, thermostat housing, water pump (easy to check, check to see if its running straight, if not, check it out), headgaskets usually show up as mayo so youre okay, check for damp patches in passenger compartment...shows signs of matrix leak, rare on mk3's.