Headgasket was done like 100 miles or so ago mate with FAI uprated mls headgasket with shim i can't see it being that as i have done loads of head gaskets not just on mg rovers but loads of different makes and never had a problem like this but i will try a few things before i give up
just wanted to add, I've read many articles where, even after the MLS gasket + shim were installed, the HG would not fail but would allow a tiny amount of coolant to weep externally, usually the right hand front corner or around that area. The way many people have fixed this was by doing the job again and using a different make of gasket (just what I've read). But if you successfully bleed it out and that sloshing returns, then you have a tiny air leak somewhere.
right i thought i would just come back and let everyone no what i have done
so i changed the fallowing
o rings on thermostat housing
inlet manifold gasket
alloy rad
coolant cap
here is what i found in the tiny coolant pipe that connects to the top of the rad
that was wedge right in the rubber pipe so am guessing the previous owner for some reason has blocked the pipe on purpose i have no idea why haha but got that out and still had the sloshing noise but i have alot of expansion caps so i changed it a couple of time and bled the system a couple of time and fingers crossed all the sloshing noise has now gone and seems to stay gone even when left to cool
so just appreciate everyones help as it has taken me a long time and a fair bit of cash to sort the issue but she is good to go now finally
Is the screw screwed into the end of the small pipe, which was in the larger pipe?
Rust would make me think it got in before going rusty or the coolant mix was wrong causing it not to provide the correct level of protection.
O it wasn't rusty before it was removed its been sat on my garden wall for a couple of weeks before pic was take
but the bit of plastic had the screw init and was in the tiny pipe and then that pipe was connected to the rad and to the return pipe to coolant tank so was causing a big blockage in the cooling systen as coolant couldn't flow round as it should