MKII VRS boosting weird

[vRSFab92]

Noticing my mk2 is boosting weird in high revs, like it’s overboosting. EML flashes and then car doesn’t let me boost until it goes off. Sometimes it does it at low revs and it’s more noticeable, feels like a misfire and can jolt you forward when you least expect it. Cant scran a GTD when it’s like this 

[Ootohere]

Do not even try to boost then, no Super Charger & Turbo Charger below 3,500 rpm until you find the fault.

You are not getting full Limp Mode yet, you may, both lights or 1 staying on and the Turbo will be inhibited, even 2 cylinders can shut down.

Do not mess about with Fault Code reading and trying this or that, there is plenty can cause issues as you describe.

 

You can read fault codes, but 'misfires' might not even show if not enough happening in a cycle.

 

So first is the Spark Plugs, is one about to expire?  A tip could break off.

The coil can expire because a plug is about too.

 

If plugs have been changed is a pipe not properly refitted, or a 'O' Ring?

Edited 3 March, 2018 by AwaoffSki

[Ootohere]

Sorry OT,

but a member might want to speak with you about your DSG.

 

Sittingbull has a 2012 CAVE engine car that the Mechatronic Unit has failed on.

There seems to be a common issue, you he and others have had replacement engines in 2012 cars, 

and are told your DQ200 DSG did not need Service Campaign 34f7 to change to mineral oil which would mean they already had mineral oil, 

or Skoda do not know WTF they have, and what the dealer changing the engine did, software updates etc.

http://briskoda.net/forums/topic/341853-is-this-bad 

 

This.

http://briskoda.net/forums/topic/444617-7sp-dq200-dsg-failure 

Edited 3 March, 2018 by AwaoffSki

[Sittingbull]

Apparently ours is fixed, At least that's the update I got when I called the dealer replacing the mechatronic unit. Now need to wait until Monday to have it confirmed by the lad handling our car at the dealer, the lassie didn't have the job card so didn't want to say 100% it was fixed or what exactly they had done.

 

Which when you've been quoted and agreed £1750 for the repair is a slight concern. Will update once Monday comes and goes. Will be nice to get the wee car back, hopefully functioning.

 

Has vrsfab92 also had problems with the mechatronic unit after an engine change? 

[Ootohere]

^^^ Here.

http://briskoda.net/forums/topic/436440-mechatronics-unit-blowing-3-amp-fuse 

[vRSFab92]

Hello. It’s weird because it will boost if I wind the throttle in slowly. Planting the accelerator gives me the weird boost spikes. My DSG packed in last July. Mechatronic unit removed and sent to a specialist in Derby for repair. They found no fault so it was reinstalled in my car and basic adaptations performed. Ran fine since. My guess is some fluid had leaked from the mechatronic unit itself and into the gearbox as I noticed the gasket was stretched. 

[Ootohere]

So on the boost issue.

 

How many miles has that engine done.

When were the spark plugs last changed, and what were fitted at the time, and did you fit them?

Is the rest standard, coils, air filter / intake, mapping, exhaust?

Has the fuel filter been replaced yet.

 

?

Do you understand how the Supoercharger is on til 2,400 rpm, then turbo comes in and both til 3,500 rpm.

Then Turbo,.

 

I

Edited 3 March, 2018 by AwaoffSki

[vRSFab92]

106k, spark plugs changed at 99k. BKR7s installed by a garage. Rest is standard except centre resonator delete

[Ootohere]

not 106,000 on that engine is it?

 

Anyway, i suspect the Water Pump might be the issue if not changed already. 

Water Pump and Supercharger magnetic clutch.

 

As to those BKr7, 

plenty have had them burn out or 1 does in 5,000 miles.  Not a 'simply clever' plug to use.  Short life. 

[vRSFab92]

Water pump changed at 100k. All went wrong at once.  Gearbox first then 2 hours later waterpump fully packed in. I have 4 new BKR7s as I suspected it to be the issue originally. 

[Ootohere]

Do you mean 4 new ready to fit?

Please take pics of those you take out, and keep them in order to see which cylinder is burning / fouling the plug.

[vRSFab92]

Yes. 4 new ready to fit in the boot. Should have seen the plugs that were in before these ones. Must have done 30/40k on them. 

[Ootohere]

?

What were those spark plugs, the same?

 

When the new engine went in it came with OEM plugs (NGK), it should have been the 2nd OEM type.

?

How many miles were on the new engine when you bought the car?

[Sittingbull]

18 hours ago, vRSFab92 said:

Hello. It’s weird because it will boost if I wind the throttle in slowly. Planting the accelerator gives me the weird boost spikes. My DSG packed in last July. Mechatronic unit removed and sent to a specialist in Derby for repair. They found no fault so it was reinstalled in my car and basic adaptations performed. Ran fine since. My guess is some fluid had leaked from the mechatronic unit itself and into the gearbox as I noticed the gasket was stretched. 

 

The place in Derby must have caught yours in the nick of time, I'm afraid we weren't so fortunate with ours. Ours had been performing brilliantly for a couple of weeks however, unknown to us, a pressure pump had failed inside the unit causing an excessive oil leak to bust the unit to the point we were motionless and unable to select any gear at all. In your case it sounds as if they've caught it just in  time as your gasket still intact albeit stretched.

 

Aside from the gearbox issue, I'm noting another common theme emerging. Your car is also manufactured April 2012, like ours and another 2 I know of now, early arrival black pack models. Also had an engine change, no service action on the DSG, and then a DSG failure.

 

Worryingly, and admittedly you are 40k further down the line than us in terms of miles covered, you're noticing problems with boosting issues and potential spark plug problems. This does concern me, we do have a full service history and touch wood the engine hasn't missed a beat since getting replaced in 2014 nor has it used a drop of oil.

 

But it is a concern, confidence has been dented. To be honest we need to commit to the car after spending £1750 to get the mechatronic unit replaced but my goodness it's a worry going forward.

 

[vRSFab92]

All sorted. Plugged it into a snap on diagnostic machine at my local garage and it found misfires on all cylinders. Got them to reset it and then made the car boost funny again. Went back and only one code remaining. Bank 4 misfire. Changed all plugs and it’s sweet as a nut now

[Sittingbull]

Very quick update here, pleased to note vrsfab92 all seems to be ok now with yours.

 

Unfortunately not so with ours. We still don't have car back, dealer has been unable to upload/ install basic settings to MCU therefore the car remains undriveable at the moment. Still no idea when it will be sorted.