Coolant issues

[Bennos17]

I’ve recently dropped all the old coolant out of the block and the radiator and now the car won’t get up to temperature.
The needle is sitting on the blue part of the gauge and won’t go up even as the engine is getting hotter.
The blowers are all running as hot as they were before and have bled to the best of my ability with the screw on top of the expansion tank.
The thermostat worked perfectly before this so all I can think of is I have loads of air trapped in my engine block
Any help would be appreciated
Tia

 

[colb]

I would suspect the temp sensor or guage in first instance if it was ok before you changed the fluid.
Try checking the instrument cluster test using the odo setting button to run the instrument test sequence to see if the temp guage actually works. Link how to here also on this forum I expect https://www.zroadster.net/forum/viewtopic.php?t=20201

If the guage works then turn your attention to the temp sender, check this out by grounding the signal wire and see if the guage swings across the scale. If it fails then change the sender unit. If it swings then it could be an air lock in the system. To get all the air out raise the front of the car as high as you can get it and run the engine and use the bleed valve to expel any air.

 

[Bennos17]

I didn’t raise the front end it might be that
Good shout
Will post back if that does the trick

 

[Ianmc]

When changing the radiator, water pump and thermostat (three separate occasions) I had heck of a job bleeding the air out of the system. That said, my car "overheated" rather than ran cool. Assuming the temp needle is moving up a bit (if not a wire could have come off), I would give the car a good run (with a bottle of coolant in the boot). This should clear any air lock.

 

[Bennos17]

Update on this I found the issue
Thermostat was the culprit turns out it was the original one
Not done too badly for 20 years of work
Thanks for comments tho

 

[Stevo7682]

Much massage of the main hoses when filling helps a lot try push the air up to the top.