Cupra R Problem Diagnosis

[mattpark]

Afternoon All.

Just nipped to B&Q to pick up some odds and sods for the weekend job list.

The cupra is misbehaving badly on boost.

The Problem
Car drives perfectly fine under lazy driving.
Foot to the floor in any gear results in a small amount of successful boost, and then the engine judders horribly, and all power is lost.
If you boot it again immediately after, there is no attempt at boost at all.
Leave it a small amount of time, and you can repeat this whole process again.

I would say its much easier to induce the juddering in a higher gear than a lower one.

Obviously something amiss. I'm waiting on my laptop recharging, then i'll go out and see if VAG COM picks anything up.

Tinkers are listed in my signature.

Help much appreciated.

Cheers,
Matt

 

[Feel]

Do you get an engine light on when it judders? When it goes away, does it go away without turning the ignition on and off?

I'm guessing it's a coilpack on it's way out.

 

[mattpark]

Hi Phil,

No engine lights get involved at all.

I can repeat that cycle every time without fail. I haven't yet been out for another spin since turning the car off.

VAG COM came back with one fault only:

16804 - Catalyst System, Bank 1: Efficiency Below Threshold.

 

[Reg]

Reckon it must be the New Car Smell Magic Tree.

 

[mattpark]

Reckon it must be the New Car Smell Magic Tree.

I could have put my life on someone saying that!

 

[mattpark]

Surely a dodgy coil pack would be picked up by the ECU and ping back a fault code?

Perhaps this issue could be related to a strange squeal i've been hearing, which is becoming more apparent. Almost sounds like a belt slipping?

 

[Feel]

Yeah dodgey coilpack would give you a "knock sensor signal too high".

The other guess I had was MAF. Try running it unplugged and see if it still does it.

 

[mattpark]

Just went out to see if i could teast any more info out the car.

Progress!!!!

16684 - Random/multiple Cylinder Misfire Detected
p0300 - 35 - 00 - -

16685 - Cylinder 1: Misfire Detected
p0301 - 35 - 00 - -

That's fairly definitive of a coil pack issue isn't it? Just the one on cylinder 1 I assume?

What's the damage for a replacement, and which cylinder is 1.. far left (looking at it with the bonnet up)?

Cheers,

Matt

 

[m0rk]

yup, far left, consider spark plug too though

 

[Feel]

That's the one (do I win a prize? ). Yes number 1 is the far left hand one. I think they're £20 ish.

 

[BCM]

bout 27 incl vat from dealer mate, glad you found out what it was! easy job, just be carefull pulling them out just incase there a bit rcked and any cap stays in the housing!

 

[mattpark]

That's the one (do I win a prize? ). Yes number 1 is the far left hand one. I think they're £20 ish.

Okay... you can have a free hosting account if you like!

Thanks for the help peps!

 

[Feel]

If you're worried it might be the spark plug like m0rk suggests, swap coilpacks between 1&2 and see if the problem moves.