It's the second flight, that I have this red line on N1 value, but can't find a a solution.

On the QRH I find the condition but not the solution on page 173.

Any advice?

It's just an advisory, so nothing you can really do. Once you shut the engine down, it should clear.

1 hour ago, Captain Kevin said:

It's just an advisory, so nothing you can really do. Once you shut the engine down, it should clear.

ok, but this is my second flight with this state, need I to send to a check?

1 hour ago, simbio said:

ok, but this is my second flight with this state, need I to send to a check?

Check your active failures.

Why not upload a photo so that we can all see exactly what you are referring to? 

The red N1 line displayed at the top of each engine's N1 strip instrument on the Primary EICAS display is fixed and shows the N1 RPM Operating limit.  However, if you are talking about the actual N1 RPM and/or the N1 RPM Indicator changing from its normal white operating range to amber and then red, this means that the engine's N1 has exceeded its operating limit beyond a set amount of time and the indication(s) will remain locked on red until it is reset at the end of your flight - i.e. as in real life (and probably not until the engine has been changed)! 

Engineering should check to see how long the engine was at specific temperatures/speeds, to see what maintenance checks will be required (not always an engine change, but may simply be an inspection). After maintenance has been completed, the "exceedance" has to be erased from the non-volatile memories in the instrument display computers using the CDU Central Maintenance Computer ("Chapter 71") pages on the real aircraft.

13 minutes ago, Qavion2 said:

Engineering should check to see how long the engine was at specific temperatures/speeds, to see what maintenance checks will be required (not always an engine change, but may simply be an inspection). After maintenance has been completed, the "exceedance" has to be erased from the non-volatile memories in the instrument display computers using the CDU Central Maintenance Computer ("Chapter 71") pages on the real aircraft.

Luckily these days we can do condition monitoring of the engines at engineering department. 

Today no more red line, here an image about what was like

FCOM 7.10.7.  The box turns read when N1 operating limit has been reached.  Are you overriding the thottles?  You'll never see this with proper use.

For future reference, every symbol on every display is explained in the FCOM.  Good first place to look.

6 hours ago, simbio said:

Today no more red line, here an image about what was like

Did you try a RECALL on the EICAS control panel to see if the red returned?

2 hours ago, Qavion2 said:

Did you try a RECALL on the EICAS control panel to see if the red returned?

Nope I will try next time.

Thank for your imput and everybody who help.

On 12/23/2018 at 10:31 PM, Qavion2 said:

Engineering should check to see how long the engine was at specific temperatures/speeds, to see what maintenance checks will be required (not always an engine change, but may simply be an inspection). After maintenance has been completed, the "exceedance" has to be erased from the non-volatile memories in the instrument display computers using the CDU Central Maintenance Computer ("Chapter 71") pages on the real aircraft.

Quite right too, John! 

Having seen Fabrizio's screen capture I should perhaps explain that the reason why the box enclosing the digital N1 readout will remain red in color is to act as a reminder to the pilot of the N1 exceedence. Unfortunately, I don't have specific information on all of the possible engine variants, but on some B744's it is possible to change the red box back to white and recall it back to red again by selectively pushing the Recall or Cancel button on the EICAS display panel.