Hi I'm new to this forum and was wondering if someone could shed some light on my problem before I go into a garage..

 

I've just bought a mk2 skoda superb 1.4tsi 2011 with 59000 miles and when I'm driving the EPC light will flash then stay on for 4 seconds and it limits my power then after 4 seconds it goes away....

 

everything seems good. No hard fault codes showing on computer I plugged in. It has done this about 10 times since I've bought the car two nights ago. 

If the EPC comes on it should log a fault if checking with ODIS or VCDS, some others may not. It could be many things from low fuel pressure to misfire or throttle adaption or broken wires or throttle pedal etc etc......

20 minutes ago, 3T51704x4 said:

If the EPC comes on it should log a fault if checking with ODIS or VCDS, some others may not. It could be many things from low fuel pressure to misfire or throttle adaption or broken wires or throttle pedal etc etc......

I had a friend who had VAG COM software and this is what came up. Since then I've changed the fuel filter. Used a fuel cleaner additive.  Tried to run shell v power 99 octain. Tried changing both the map sensors with new Bosch ones but still no different. Sometimes it wont put the light on dash and will just put car into soft limp mode. Limiting my boost to around 4psi. Normally runs 9-11psi. I have a cheap realtime code reader which shows me my realtime info such as boost ect. I'm stumped on what to do next. Dont really want to be buying all new sensors like knock sensors ect.... 

29 minutes ago, 3T51704x4 said:

If the EPC comes on it should log a fault if checking with ODIS or VCDS, some others may not. It could be many things from low fuel pressure to misfire or throttle adaption or broken wires or throttle pedal etc etc......

I have searched up on ross tech about this code and on vw forums and I've come across a few other people with this problem  . They changed map sensors and all was good but still having problems.  Done a lot of research and I've heard of people putting their cars into garages and dealers and they still cant trace the problem after spending more money that what the cars worth... 

@Kyle1994

You can have misfires and there not be enough in a cycle to have fault codes logged.

?

Have you had the spark plugs out.  Checked they are the correct ones with the correct gap?

Start with checking all 4 spark plugs, then the ignition coils. 

 

Edited 20 August, 20205 yr by e-Roottoot

Trouble is you need to understand what is happening prior to the parts bingo. You could fit a new sensor and by disturbing the wiring going to the sensor, it may have had a partially open circuit which will allow the new sensor to give the correct signals to the ecu but could fail again when the engine vibration takes hold.

The 5v feed, earth and signal wires need to be scoped (or looked at by other means) to see exactly what is happening. I repaired a wiring loom the other day on a T6 where someone had replaced the oil level and temperature sensor unit to have the same problem. I found the signal wire back to the ecu was OK, but the 5v feed and earth wires were severed within the PVC insulation within the loom.

I have also seen this many times for the new additional coolant pumps on CR35s, the loom under the sump in the corrugated sleeving is the cause in 70% of cases, not the pump

Sometimes spending a little more on garages with the correct diagnostics and people able to interpret the results saves you money in the long run.

5 minutes ago, e-Roottoot said:

@Kyle1994

You can have misfires and there not be enough in a cycle to have fault codes logged.

?

Have you had the spark plugs out.  Checked they are the correct ones with the correct gap?

Start with checking all 4 spark plugs, then the ignition coils. 

 

Someone with experience would know it was misfiring though.

Scope with cylinder pressure sensor/ COP sensor would show the workshop if the crank was speeding up or slowing down, don't need to wait for the ecu to log it. 

@3T51704x4

I wish i had a £1 for every Mechanic / Technician / DIY'r with all the gear and not the time to whip out the plugs and inspect them.

Especially with 1.2 & 1.4 TSI's. Euro4 & Euro 5.

Proper diagnostic techniques save hours and lots of money:

 

 

 

 

3 minutes ago, e-Roottoot said:

@3T51704x4

I wish i had a £1 for every Mechanic / Technician / DIY'r with all the gear and not the time to whip out the plugs and inspect them.

Especially with 1.2 & 1.4 TSI's. Euro4 & Euro 5.

Yes but if they are fine then what.

More likely to be the HT leads or coil pack, or injectors or carbon on the back of the valves.

7 minutes ago, 3T51704x4 said:

Someone with experience would know it was misfiring though.

Scope with cylinder pressure sensor/ COP sensor would show the workshop if the crank was speeding up or slowing down, don't need to wait for the ecu to log it. 

I have worked in a mechanic garage for 3 years previously so I would know what a misfire sounds/ feels like. Will have a look at wiring loom tomorrow when I get chance. And for peace of mind il take the plugs out and check the gap clearance.  Had a full service with previously owner inc plugs last year. And I have already had the car in at two garages that I trust. One of them I used to work for. They both cant find the problem and just says it's bad fuel. 

@3T51704x4 Then move on and do what needs doing., as many that buy cars lots do. Just do basics first.

Expecting to do a basic service on a vehicle new to you is just 'simply clever', 

looking in the air box at the filter and checking the spark plugs is just so 'simply clever' and gives an idea of just what the previous keepers / seller have done.

 

@Kyle1994

I served my time in the 1970's as a Mechanical Engineer and know what misfires are yet one plug misbehaving can have a car go into limp mode or just have a Exhaust Emissions Light come on or a EPC flash and you not feel it.

 

It is a 2011 Euro 5 1.4 TSI that is being talked about here, nit a twincharger, but one that does continue the common issues that they suffer from.

 

Edited 20 August, 20205 yr by e-Roottoot

4 minutes ago, e-Roottoot said:

@3T51704x4 Then move on and do what needs doing., as many that buy cars lots do. Just do basics first.

Expecting to do a basic service on a vehicle new to you is just 'simply clever', 

looking in the air box at the filter and checking the spark plugs is just so 'simply clever' and gives an idea of just what the previous keepers / seller have done.

 

@Kyle1994

I served my time in the 1970's as a Mechanical Engineer and know what misfires are yet one plug misbehaving can have a car go into limp mode or just have a Exhaust Emissions Light come on or a EPC flash and you not feel it.

 

Right for peice of mind I will get another set of plugs tomorrow even if the old ones look okay. I have already checked the air filter. Changed fuel filter. I'm not holding out much hope tho from what I've read up on with the 1.4tsi 122 engines. 

9 minutes ago, e-Roottoot said:

@3T51704x4 Then move on and do what needs doing., as many that buy cars lots do. Just do basics first.

Expecting to do a basic service on a vehicle new to you is just 'simply clever', 

looking in the air box at the filter and checking the spark plugs is just so 'simply clever' and gives an idea of just what the previous keepers / seller have done.

 

@Kyle1994

I served my time in the 1970's as a Mechanical Engineer and know what misfires are yet one plug misbehaving can have a car go into limp mode or just have a Exhaust Emissions Light come on or a EPC flash and you not feel it.

 

It is a 2011 Euro 5 1.4 TSI that is being talked about here, nit a twincharger, but one that does continue the common issues that they suffer from.

 

Yes it's not the twincharge one. 

I will update back tomorrow evening to let you know if the plug swap did anything.  

3 hours ago, e-Roottoot said:

@3T51704x4 Then move on and do what needs doing., as many that buy cars lots do. Just do basics first.

Expecting to do a basic service on a vehicle new to you is just 'simply clever', 

looking in the air box at the filter and checking the spark plugs is just so 'simply clever' and gives an idea of just what the previous keepers / seller have done.

 

@Kyle1994

I served my time in the 1970's as a Mechanical Engineer and know what misfires are yet one plug misbehaving can have a car go into limp mode or just have a Exhaust Emissions Light come on or a EPC flash and you not feel it.

 

It is a 2011 Euro 5 1.4 TSI that is being talked about here, nit a twincharger, but one that does continue the common issues that they suffer from.

 

Cool, but you could have fitted unnecessary parts and wasted workshop time which the customer is paying for and still may be no closer to solving the actual fault, you may get the bulls eye first time, but hey not your money. Keep on playing the parts lottery till you score, lots of garages make that mistake and it's why people get fed up with some garages and move on to the next ending up with huge unnecessary bills, these forums are full of these stories. But I could be very wrong, not wanting to prove what the fault is before any parts are fitted. 

 

This then (2012) new TSi engine had been in the dealers three times for a sporadic misfire with countless parts thrown at it. Simple short due to loom routing needed no parts to fix.

 

 

 

 

 

Edited 20 August, 20205 yr by 3T51704x4

The simple fix was to open the loom and repair damaged pvc and seal it to prevent moisture ingress which will lead to black corrosion and future problems (that is why you should backprobe terminals not pierce the insulation with the probe but some will say different which is fine but not on my car) , then run the loom under the metal plate by simply clever turning the plastic cable support 180 degrees so it was pointing up. Now the loom was supported on the same metal bracket, but from underneath with the plastic support. Not a spark plug in sight.

It is good to keep things simple yes, but sometimes a simple misfire can be caused by very difficult to pinpoint faults unless you have the right gear and know how to use it.

 

Edited 20 August, 20205 yr by 3T51704x4
Typo

Great stuff. I check spark plugs anyway anytime I acquire a petrol vehicle.  I find it to be 15 minutes of my time well spent.  All the gear and full of ideas sadly is not always what is needed when basic servicing will be getting done anyway.  It is nice to just get to know as new to you vehicle and not trust service records and receipts.

Great, so would I, but I thought he  had an EPC issue?

Edited 21 August, 20205 yr by 3T51704x4