1.8 'K' Series losing coolant; overheating. HGF?

Hi all,

My Freelander 1.8 loses coolant regularly and I've been topping it up with OAT each week for the last few months whilst I find the money / time / enthusiasm to have the water pump replaced (my local Land Rover specialist identified this as the reason for the coolant loss at it's most recent service / MOT but the car's been an absolute money-pit this year so I was reluctant to spend even more on something that didn't seem absolutely essential to have repaired at the time).

Anyway...

My wife topped it up with coolant before going out the other day but she forgot to put the pressure cap back on the expansion tank before setting out on her journey. 10 miles later the temp gauge hits the red and the fan kick in but she gets home and realizes what she's done.

I've bled air out of the coolant pipe and heater inlet (outlet?!) pipe bleed screws every day for 4 days and I've blown air into the inlet manifold valve spout to ensure the valve isn't stuck. I've also replaced the expansion tank pressure cap but the temp gauge still flicks up to red after 4 or 5 miles. When I drop the revs to the engine for a bit and whack the heater on full the temp gauge does comes down fairly quickly; but if I look under the bonnet I can hear / feel the coolant in the top rad hose boiling and can see the expansion tank is fuller than it was because the coolant has expanded, and that there are drips on the side of the expansion tank where the coolant has bubbled over.

Next job is to drain the rad and flush water through it but I'm fairly certain the rad is working properly because though it is warm, the bottom rad hose is nowhere near as hot as the top hose. This and the fact that the fan is kicking in would also suggest that the thermostat is ok? But I don't really know what I'm talking about to be honest.

I was worried it could be a blown head gasket because I assume lots of air would have been sucked into the engine whilst the expansion cap was off and done all sorts of damage to the HG...I've done some HG checks: the engine oil is black on the dip stick, not greyish; there is no milky stuff in the expansion tank and whilst there is white smoke out of the exhaust at first start of the day, it soon clears, which I think is normal.

So I'm after some advice please!

I've read numerous related posts on this forum but has anyone else encountered this particular set of symptoms? Is it a case of persisting with the bleeding of air out of the system each day? If it is a blown HG what else would I be seeing? It might just be a coincidence and completely unrelated, but the engine was 'lumpy / juddery' on tick-over and when accelerating from low revs, but since I replaced the pressure cap that particular issue seems to have gone away.

Cheers

Unfortunately it sounds like a head gasket, combustion gases getting into the water jacket,
This will pressurised cooling system and Chuck water out of the overflow,
The slight missing is likely a spark plug with a bit of water that’s has cleared, again after leaving overnight
Will miss again before clearing,,
Take out plugs and if you have a very clean one and the others are carbon up that will be the cylinder leaking,
Do you get a whoosh of pressure’s when removing expansions bottle cap?

Thanks for your reply. I'll check the plugs today. I forgot to say that when I opened the expansion tank yesterday it smelt of exhaust, but I wasn't sure if that was just the smell of coolant when it reaches boiling point...

I think do get a whoosh when I open the expansion tank cap yes but I'll check that again today as well. In the meantime I'll ring around for HG quotes. It sounds expensive!

I'd make sure the cooling system is cleared of all air, before condemning the HG. However if the coolant is pressurized from cold, then it's almost certainly a HG issue. It's not an expensive job, and should take a competent mechanic no more than 4 hours to do. You need to used the Payen BW750 gasket, and not the MLS, as those don't seal so well.