Strange full throttle problem

[Stoker20VT]

When driving my Cupra in any gear FULL throttle as it gets to 3.5k ish revs it does this strange noice and hesitates and jerks.

But if you donnt drive it full throttle and go past 3.5k it drives as normal.

Problem only occurs under full throttle.

I've got 1 of them little hand held fault code finders (not vag-com i know ) and no faults are coming up.

Any ideas?

 

[Stoker20VT]

think its a boost leak..

Unplugged my MAF to see if it stopped doing it, it didnt and it threw up a fault on my little hand held thing. So it cannt be sensor related or it would show up.

not sure about coilpacks though? Wats the symtoms when they brake?

 

[john-d]

if it was a coilpack you would have em light and a very juddery car all the time

 

[Stoker20VT]

I have no idea now

Think im going to change my plugs tomorrow as a last attemp before it goes to the garage..

Changed them around 2k ago like

Also when my water cap wassnt on and i was revving it my Dad said there was bubbles and is moaning saying my head gasket is nackered.....

Could it be? No oil in water, no water in oil, no smoke, no over heating and no loss of power...

 

[CupraElliott]

Bubbles will be the overflow possibly.

It could be coils, might not throw a fault up, could be a number of things. Just trial and error, start with the simple stuff and cross your fingers.

 

[Stoker20VT]

thought i cracked it today, the n75 wassnt nipped right up to the TIP and was loose. Tightened it but nothing happened...still the same

 

[Stoker20VT]

Changed the plugs and gave it a quick blast and all seems well.

Donnt recommend NGK BKUR6ET-10 they lasted 2k miles