172 cup Flat spot over 6k

[Highland-Clio]

Hello 172 cup

The car has a flat spot between 6 and 7 k pulls stong again over 7k

New plugs

No codes

Leads good

Standard exhaust

Standard airbox

Would say engine has a slight tick from dephaser would this be a sign of it going bad ?

Cup struggles over 125mph

Thanks

 

[Russ_16v]

You say it revs fine over 7000?

As the power and torque drop off rapidly over 6800 ish on a standard 172, is yours modified?

Im guessing it's chipped, as it revs over 7k?


How bad is the noise mate? most only rattle on idle, but usually go on for a while before getting bad.

 

[Highland-Clio]

No rattle on idle sounds more like a ticking manifold noise but no leaks

Tick can be heard when driving could however be thrust bearing

It revs to 7500 !! Pulls strong over 7000

Car should be standard all parts standard exhaust, filter etc

Compression check 160 + each cylinder fine but it has worn two plug tip off completely NGK pfr6e-10

Interested in symptoms of dephaser going bad before I change it all