1.8 TSI lumpy idle when cold and tuning?

[Snowman89]

I own a Skoda Octavia 1.8 TSI 160ps 2010 that has done about 85000km.

It runs great once it is hot, however on cold starts it runs quite rough, almost like it is missing out every now and then.

It had a large service with new spark plugs for about 5000km ago.

Apart from the rough/lumpy idle it runs fine.

I'm really happy with the car and the only other thing is that it does consume some oil, about 2dl/1000km, but from what ive read this is quite normal?

 

I'm also thinking of getting a stage 1 remap to the car, is this something that should be avoided or perhaps even recommended?

It would be nice to get access to some extra horses under the hood

[Ootohere]

Best sort out your sparkplugs,be sure gapped correctly, good air filter and any oil use should be checked, before having a remap.

(sorry not sure what your oil use is, is it 0.2 litres in 1000km ?  Skoda / VW's 0.5l / 1000km figure is nonesense, )

0.2 litres / 1000km is not bad but you need to check if plugs are getting fouled then carbon build up.

It is not really an acceptable oil use though, maybe try a change of oil, correct spec but not Castrol. & not Long Life.

&

get the latest Skoda Software Update and have an efficient running engine cold or hot.

 

this is for 1.4tsi Twinchargers as a warning, but the same applies really with a 1.8TSI.   Dont remap a poor running engine, resolve as standard first.

http://revotechnik.com/support/technical/14tsi-twincharger-engine-issues

[Snowman89]

Best sort out your sparkplugs,be sure gapped correctly, good air filter and any oil use should be checked, before having a remap.

(sorry not sure what your oil use is, is it 0.2 litres in 1000km ?  Skoda / VW's 0.5l / 1000km figure is nonesense, )

0.2 litres / 1000km is not bad but you need to check if plugs are getting fouled then carbon build up.

It is not really an acceptable oil use though, maybe try a change of oil, correct spec but not Castrol. & not Long Life.

&

get the latest Skoda Software Update and have an efficient running engine cold or hot.

 

this is for 1.4tsi Twinchargers as a warning, but the same applies really with a 1.8TSI.   Dont remap a poor running engine, resolve as standard first.

http://revotechnik.com/support/technical/14tsi-twincharger-engine-issues

The spark plugs are brand new and was replaced about 5000km ago, so was the air filter and oil +filter.

Yes 0,2liter per 1000km, im not entirely sure about this though since i bought the car quite recently.

I'm running 5w-40 Bolk oil, for a maximum of 150000km.

Regarding the oil consumption, what should i try if i would like to reduce it?

 

Regarding the lumpy idle, this only occurs when the car is cold and the tickover is elevated.

Once the idle/tickover settles at around 800rpm the lumpy running dissapears.

Edited 15 July, 2016 by Snowman89

[Snowman89]

Anyone...?

Edited 16 July, 2016 by Snowman89

[brad1.8T]

Probably carbon build up on the inlet valves.  Easily confirmed using a cheap ebay endoscope plugged into a laptop.  Feed the camera through the Air temp sensor hole and have a look at the air splitters and the valves

 

As goneoffski said - double check the plug type / partno and also the gap.  It's amazing how many "professional" mechs stuff this up.  About the only other thing I'd look at is coils.  They are cheap / easy to replace so maybe do them as a preventive maintenance measure and keep the old ones as spares

 

Stage 1 tune is a must.  I've had one for the past 140,000km without issues

Edited 17 July, 2016 by brad1.8T

[Snowman89]

Probably carbon build up on the inlet valves.  Easily confirmed using a cheap ebay endoscope plugged into a laptop.  Feed the camera through the Air temp sensor hole and have a look at the air splitters and the valves

 

As goneoffski said - double check the plug type / partno and also the gap.  It's amazing how many "professional" mechs stuff this up.  About the only other thing I'd look at is coils.  They are cheap / easy to replace so maybe do them as a preventive maintenance measure and keep the old ones as spares

 

Stage 1 tune is a must.  I've had one for the past 140,000km without issues

How does your car behave on a "cold" start?

As i mentioned i only notice this on cold starts and it dissapears once the idle backs down.

 

I tried googling some and many people seem to have different problems with the lumpy idling, however many people just say that is how the TSI engines are nowdays..

[Snowman89]

If it would be caused by carbon buildup on the inlet valves, how is it that i just notices it when the car has the elevated idle?

 

I bought the spark plugs from mister auto.

Sure i could go ahead and replace all 4 coils, but i dont really see what i should do that since the car runs just fine once it passed the first 5-10seconds when the idle seems to be a bit unstable.

[brad1.8T]

How does your car behave on a "cold" start?

As i mentioned i only notice this on cold starts and it dissapears once the idle backs down.

 

I tried googling some and many people seem to have different problems with the lumpy idling, however many people just say that is how the TSI engines are nowdays..

Mines runs like a swiss watch - hot or cold

 

If it would be caused by carbon buildup on the inlet valves, how is it that i just notices it when the car has the elevated idle?

 

I bought the spark plugs from mister auto.

Sure i could go ahead and replace all 4 coils, but i dont really see what i should do that since the car runs just fine once it passed the first 5-10seconds when the idle seems to be a bit unstable.

You notice it when it's cold.  It's to do with the engine not being at normal operating temperature and the difference in expansion characteristics of the different metals in the head /valves. (that's my theory}.  Back in the old days before direct injection, it was easy to explain a ratty cold idle due to carbon - basically the cold carbon was sucking up the fuel.  With DI, all I can think of is disimilar expansion rates and possibly the valves not sealing perfectly.  Your mileage is about right for the problem.

As I said, it's cheap to check.  Buy a GBP15 endoscope off ebay.

 

"I bought the spark plugs from mister auto." doesn't really answer the question of make / partno & gap.

 

The coils are just a PM thing.  Cheap to do - about GBP70 for 4 red top Audi R8 units.  But yes, your choice.

[Snowman89]

Mines runs like a swiss watch - hot or cold

 

You notice it when it's cold.  It's to do with the engine not being at normal operating temperature and the difference in expansion characteristics of the different metals in the head /valves. (that's my theory}.  Back in the old days before direct injection, it was easy to explain a ratty cold idle due to carbon - basically the cold carbon was sucking up the fuel.  With DI, all I can think of is disimilar expansion rates and possibly the valves not sealing perfectly.  Your mileage is about right for the problem.

As I said, it's cheap to check.  Buy a GBP15 endoscope off ebay.

 

"I bought the spark plugs from mister auto." doesn't really answer the question of make / partno & gap.

 

The coils are just a PM thing.  Cheap to do - about GBP70 for 4 red top Audi R8 units.  But yes, your choice.

Thanks for your reply!

I did actually order a endoscope from ebay yesterday, hopefully it will arrive soon so i can have a look.

If this would be the case, how would i clean it?

 

The sparkplugs are "BOSCH 0 242 245 576".

However i did not checkthe gap, i just pulled them from the box and fitted them..

 

What about the R8 units, are they supposed to be better?

Please post a link to them, would be good to know in the future anyway since i know they failed often on the previous 1.8T.

[Snowman89]

One thing that is interesting with the lumpy idle is that it is only there when the idle is elevated.

Once the "choke" function of the injection lets the idle down to the real idle RPM, then the lumpyness dissapears..

[brad1.8T]

The partno is right.  I run mine at a loose 0.028" but the recommended gap is 0.031" (0.8mm).

 

The R8 units have a few extra windings and put out a slightly fatter spark.

 

If the inlets are carboned up you might get away with a chemical clean but the guaranteed way is to remove the intake manifold and scrape the carbon off.

 

If it's just for 30 seconds, can't you just live with it?

[planehazza]

If it would be caused by carbon buildup on the inlet valves, how is it that i just notices it when the car has the elevated idle?

 

I bought the spark plugs from mister auto.

Sure i could go ahead and replace all 4 coils, but i dont really see what i should do that since the car runs just fine once it passed the first 5-10seconds when the idle seems to be a bit unstable.

 

I doubt it's carbon buildup. Mine has really bad after 68k miles and I wasn't getting a lumpy idle - the revs weren't moving at least.

[Snowman89]

The partno is right. I run mine at a loose 0.028" but the recommended gap is 0.031" (0.8mm).

The R8 units have a few extra windings and put out a slightly fatter spark.

If the inlets are carboned up you might get away with a chemical clean but the guaranteed way is to remove the intake manifold and scrape the carbon off.

If it's just for 30 seconds, can't you just live with it?

Ofc i can live with it.

However i would like to remap the car and i was adviced in the begining of the thread to sort out the problems before remapping.