Afternoon everyone, 

Ive recently bought an Octavia 1.8TSI estate (2011) on a private sale. The engine starts easily, idles well (not lumpy or noisy) and the car drives well through all gears, the engine sounds great generally.....however.....

 

If you accelerate hard, pushing to about 3500 rpm the EPC warning light comes on and there is a restriction in power, not a huge restriction but certainly limited. The EPC light remains on until cleared using an OBD2. 

 

The OBD2 shows no fault codes. Once cleared (though there is nothing identified to clear?..), the car drives as it should and the engine provides decent power, until its pushed a bit harder again and the EPC light comes back. The light doesnt ALWAYS illuminate when the car is pushed but it doesnt take long.

 

Does anyone have any idea whats going on here? 

 

Ive contacted the seller who swears this never happened to them so no clarity there (i dont believe this for a second but you win some you lose some, etc) so im trying to be constructive and just hoping to rectify this with minimum fuss. Otherwise it seems a decent car and I'll keep it for a while. 

 

Cheers for any advice you can give

 

Hello DC, welcome to the forum.

Are you aware of the well documented issues with the EA888 engine? Have you driven it long enough to see if it is using engine oil? 

Misfires, plug / plugs failing maybe, ignition coils maybe.  The Spark Plugs need inspected and the gaps checked.

 

Have you filled up with fuel and is it E10 you bought and has the previous keeper maybe used E5 'Super Unleaded 97 or 99 ron? 

19 hours ago, Warrior193 said:

Hello DC, welcome to the forum.

Are you aware of the well documented issues with the EA888 engine? Have you driven it long enough to see if it is using engine oil? 

I wasnt but am seeing a number of reported issues since ive been looking online. Ive only driven it for a couple of days so can't say definitively re oil use but will monitor this, though theres no obvious significant use at this point, certainly no identifiable leak or smoke etc. 

 

19 hours ago, Ootohere said:

Misfires, plug / plugs failing maybe, ignition coils maybe.  The Spark Plugs need inspected and the gaps checked.

 

Have you filled up with fuel and is it E10 you bought and has the previous keeper maybe used E5 'Super Unleaded 97 or 99 ron? 

Ive not needed to refuel yet and dont know what will have been used previously / currently using. 

Re misfire, plug or coil failures, would this likely show as a fault code or can this trigger warning lights without a registered code?

Im not hearing or fealing it missing but possibly it could be briefly, enough to trigger a sensor?

 

 

I appreciate your replies guys. I'm able to make general repairs and do 'bits' but have no / very little knowledge around engine specifics and diagnostics. This was a car bought as I got on pretty trouble free with a Mk1 octavia years back, saw this Mk2 that looked decent and now have a family to put in it so just went with it. Id have bought it with any engine in all honesty.

 

 

Misfires logged as fault codes require enough happening in a cycle. 

You have the EPC light on so there might be codes logged.

 

Having them read is quite important. Essential really.

 

Maybe get some Tesco Momentum 99 (99 ron min)  in and see if any difference.

Check the air filter, and have the spark plugs checked, and replaced if needed.

I'm getting my hands on a decent scan tool tomorrow so will see if that shed's any light and let you know.

Cheers again

 

Suggest check for DTCs referring to any under boost issues.

Coils do go on these, had similar symptoms on mine but it did flag a code I think. I changed all 4 coils (I knew which one failed but I changed all 4 as a precaution) and it's been perfect since.

 

As a side note the 1.8tsi does generally use oil, mine does and always has. It's not got any worse in 60k miles and 11 years so just be aware and ready to top up.

Edited 27 November, 20241 yr by goatboy

1 hour ago, goatboy said:

Coils do go on these, had similar symptoms on mine but it did flag a code I think. I changed all 4 coils (I knew which one failed but I changed all 4 as a precaution) and it's been perfect since.

 

As a side note the 1.8tsi does generally use oil, mine does and always has. It's not got any worse in 60k miles and 11 years so just be aware and ready to top up.

@goatboy Were you getting misfiring with the faulty coil, if so, was it particularly noticeable? 

Yes, very noticeable!

A more in depth scan gave:

'P0234 turbo / supercharger overboost condition'.

 So at least ive got something to go at now. 

 

I'll start with the MAP sensor and look at the waste gate and actuator but I have no time until the weekend.

I changed the MAP sensor last night and that seems to have resolved the issue (fingers crossed), the car now drives as it should and has full power throughout, no recurring EPC light.

So long as this continues ill be keeping the car so will look to tidy up the few bits i knew about when i bought it. Discounting this minor drama its looking like a fair buy,

Thanks for your support, no doubt i'll be back asking about something else at some point!

Cheers