[zt190] overheat, then not, then overheat, then not ???

[kaiser]

There is no reason to bleed anything. Just top up when cold.

The one liter that has gone in is most likely the majority of the trapped air from the last top up.

These engines are self-bleeding, which means any trapped air will find its way to the expansion box, once the thermostat opens and the revs are high enough.

So if you refill when cold, you are filling the trapped air, but do checks and see if the level stabilizes.

I think you will find there is a small loss.

Bleeding is only required if you want to try and do the whole operation in one session.

[Ivan]

gunna keep an eye on coolant levels every morning, and replace the thermostst when the new one arrives (bah @ christmas postage )

one quick question, assuming say the thermostat is siezed shut (worst case) would i still be ok to run around in the car .... providing say the journey is as short as possiable (max say 10miles)

[MrDoodles]

As a KV6 will usually be up to temp in 2 miles, if the thermostat is stuck closed, any further than that will over-heat the engine!

[SD1too]

Originally Posted by kaiser

There is no reason to bleed anything.
These engines are self-bleeding, which means any trapped air will find its way to the expansion box ...

Kaiser,

MG Rover specifies in its official technical manual that the cooling systems of all the 75/ZT engines should be bled using the screw plug provided. I find it hard to believe that a manufacturer would do this if it wasn't necessary, but perhaps it's a 'belt and braces' approach. On the other hand, it may well be that the coolant level in the expansion tank may not be the highest point in the system; hence the provision of the bleed screw. Another possibility is that it was found during development that the convoluted hose route does trap air unless it is vented.

The KV6 is a special case because MGR specifies that the expansion tank should be raised whilst filling. It seems to me that the company probably found that unless this was done, there was a possibility that an air lock could be created. Since many members use independent garages who do not consult MG Rover's manual it is highly likely that they do not raise the expansion tank on the KV6 or, I suspect, use the bleed screw on any of the engines. It seems sensible to me to take the precaution of eliminating this possibility before pursuing more involved and expensive procedures.

You have expressed your view on this many times and you are, of course, entitled to do so, and it all adds to the debate. It should be remembered though that there is no evidence in MG Rover literature stating that the engines are "self-bleeding".

Simon.

[SD1too]

Originally Posted by Ivan

one quick question, assuming say the thermostat is siezed shut (worst case) would i still be ok to run around in the car ...

No, but if the 'stat isn't opening at all you would get much more severe overheating symptoms than you have reported.

When the water pump was renewed, were you charged for a new straight plastic coolant pipe or, at the very least, two new 'O' ring seals?

Your mileage (62,000) is around the time that the plastic coolant components often give trouble.

Simon.

[Ivan]

Originally Posted by SD1too

No, but if the 'stat isn't opening at all you would get much more severe overheating symptoms than you have reported.

When the water pump was renewed, were you charged for a new straight plastic coolant pipe or, at the very least, two new 'O' ring seals?

Your mileage (62,000) is around the time that the plastic coolant components often give trouble.

Simon.

well i suppose thats good to know

errrr i dont think so .... but i cannot remember if i am honest

[scouseeric]

Hi Ivan,
are you still getting a steamy exhaust? if so then you most likely need new inlet manifold gaskets mate,hth

Eric

[andy willi]

i fitted the water pump on this car and i did it right there might be a leak somewhere or its just like my 190 the rad cap is failing


andy

[Ivan]

Originally Posted by andy willi

i fitted the water pump on this car and i did it right there might be a leak somewhere or its just like my 190 the rad cap is failing


andy

hey Andy, hows things

i can report that there is absolutly no problems what so ever with the work you did mate, that side is running sweeet.

i think that my gamble on the thermostat, is at an end though lol (if i remember correctly you did advise me to get it done, but at the time my funds didnt allow)

i knew the risks then as i do now.

just need parcel force to hurry up !!!! lol

[Ivan]

Originally Posted by scouseeric

Hi Ivan,
are you still getting a steamy exhaust? if so then you most likely need new inlet manifold gaskets mate,hth

Eric

i always get a steamy exhaust at this time of the year, so i cannot say either way ..... that said i do believe my car still has its original OEM exhaust.