Overheating issues

[domsz4]

Any ideas what might be causing an overheating issue? Thermostat and water pump have both been replaced. But it just runs up from cold straight to over heating.

No hot air is coming into the cabin and it looks like there is no hot water going into the radiator the top hose which connects to the expansion tank is hot but the bottom hose that connects the stat to the rad is cold

[raymond.harper]

Take the thermostat out test to see if it is stuck shut. There are plenty of failures of " quality" new parts at the moment. What engine do you have?

[enuff_zed]

Which engine?
Funnily enough I have just spent this afternoon battling an N52 with the same issue after I replaced the dead electric pump and thermostat.
Turned out to be a massive airlock in the heater matrix.
Jacked it up as high as I could at the front and I think I counted another seven runs through the automated bleed procedure.
Finally sorted.

[domsz4]

It’s the m54 3.0 engine…. taking the stat off (it’s all one unit) is an option as the only thing I can think of is it’s an airlock or some debris is blocking the system so draining and flushing the system is my next job

[domsz4]

Which engine?
Funnily enough I have just spent this afternoon battling an N52 with the same issue after I replaced the dead electric pump and thermostat.
Turned out to be a massive airlock in the heater matrix.
Jacked it up as high as I could at the front and I think I counted another seven runs through the automated bleed procedure.
Finally sorted.

Kinda where I’m at

[Trav]

If you can try to measure it in you will have an airlock if you don't get the full 8.3 litres of fluid in the system.

[domsz4]

Full drain drain down, back flushed the block, heater matrix, and radiator as best I can and then refilled seemed to have done the trick.