About to give up on my MGF - I think I have tried everything.

What year is it?
MPI, VVC or Trophy?
MEMs 1.9, 2J or 3?
Oh and I was editing my above post on the run, so you might want to reread it as there have been additions.

Bertl wrote: I had the same issue years ago - for me it was a clogged toggle valve in the inlet manifold. Try to clean it.

Yep it was clogged - cleaned it when I removed manifold. But still no joy.

iambob wrote:
Yep it was clogged - cleaned it when I removed manifold. But still no joy.

did you renew the gasket when refitting the manifold?

Cobber wrote: What year is it? 2001 - UK import
MPI, VVC or Trophy? MPI
MEMs 1.9, 2J or 3? MEM3

Bertl wrote:

iambob wrote:
Yep it was clogged - cleaned it when I removed manifold. But still no joy.

did you renew the gasket when refitting the manifold? Yep new gasket too - I have been trying so many things

Sometimes just filling the cylinder with compressed air at TDC will indicate a problem, is the air leaking trough to the crankcase? or bubbling the coolant? See no bubbling
Are al the coolant hoses going where they should? Sometimes the minor hoses can be connected to the wrong nipples, this can cause interruption to the proper flow. I have spend a long time checking the water flow and pipes - removing checking and flushing. Trying to understand why the flow seems to run the bypass in priority to the radiator at idle. Can only ponder there is some sort of restrictor under the jiggle valve?
Lean fuel/air mixture can cause hot running, check for vacuum leaks, check sensors particularly temp sensors are correct, the wrong plug can be on the wrong sensor, so check all the plugs are on the right sensors. Have checked and replaced ECU temp sensor just in case it was giving wrong reading
Don't assume that anything is correct until its been properly checked. I assume nothing on a MG

Just bled some more air out of the radiator after the last overheat. It was bled just before my drive so I think something is pushing it back in. Might have to see if I can get a sniff test.

Just replaced head gasket . Thermostat had stuck shut . Fitted PRT near radiator having taken guts out of original thermostat near water pump. All is now running well .BUT on engine shut down there is quite a bit.of pressure and residual heat in header tank . Still all's well when cool . A good battery also helps . They need s good fast turn over for easy starting . Now fitting ally rad when it arrives from nice ebayer owner .
So true .the body is good where it's solar red ..Any black powder coated items almost rusted away . Security panel below bonnet catch just almost not there .Think I'll leave it off. .Subframe just ok ..spare wheel panel and all red things like new . Great playthings

iambob wrote: Just bled some more air out of the radiator after the last overheat. It was bled just before my drive so I think something is pushing it back in. Might have to see if I can get a sniff test.

That's what I had, bleed rad go for run, all fine while moving, overheat while standing all fans running, get home coolant raised in tank air in rad, all caused by exhaust gasses that sniff test failed to show but bore scope proved with wet cylinder when cool.

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