Does anyone know if the Octy 3 VRS TSi has any new features to help reduce the inlet carbon build up that plagues the earlier version on this engine?

 

I read somewhere that the Golf  7 GTi  has extra injectors into the manifold (ie on top of DI) to meet EU emissions and that as a side effect this means the mainfold and backs of valves actually get washed by petrol a bit reducing the build up.

 

Any info if the Octavia 3 Petrol VRS is the same and views on effectiveness?

 

Obviously maybe a bit too early for many Octy 3s to have these problems, but I would not buy another TSi unless its fixed. 

 

As a word of warning my Skoda dealer wanted to replace the inlet manifold and remove then cylinder head for cleaning on my 50K TSi with a potential bill of £1000+ due to these deposits which appear to be a routine thing...

Yes the EA888 gen 3 engine has both FSI and MPI injectors.

 

Having the MPI and FSI injectors and the ability to switch them to suit the situation gives the engine management the best of both worlds between the two methods of injection

 

Having the MPI (manifold injection) means that there is a fuel mix washing over the valves for a proportion of the time which helps keep the carbon build-up down.

 

Time will tell if the amount the MPi is used (AFAIK idle and full load) will make a difference but it has to help

 

Certainly cars that had manifold injection did not suffer like the cars with direct (fsi)-only injection. The older RS4 was a pig for coking up but at least the V8 made the inlet ports easier to get at and blast.

The mk3 1.8 and 2 litre versions have the direct and inlet injectors. 1.4 and below only have the direct injection.

More info below

 

http://www.oilem.com/turbo-fuel-stratified-injection-tfsi-direct-port-injection-carbon-build-up-problem/

The mk3 1.8 and 2 litre versions have the direct and inlet injectors. 1.4 and below only have the direct injection.

Oh well good news (1.8 & 2.0) bad news (1.4)

It amazes me just how little bad publicity VAG and other manufacturers have had regarding direct injection and carbon build up.

Hmm does not sound good for 1.4tsi engines, you would think they would design engines to address these known flaws

Just out of curiosity. Would using a couple of shots of either Redex or Miller's Petrol Ecomax do any good?

Just out of curiosity. Would using a couple of shots of either Redex or Miller's Petrol Ecomax do any good?

I don't see how they could have any effect for the 1.4tsi as the carbon buildup occurs mainly on the inlet valve stem.

Port injection allows the inlet valve to be 'washed' down with the petrol on the way to the cylinder but the direct injection system is direct into the cylinder.

I'm not aware carbon build up is a problem for the current Golf 7 GTI or vRS sold in Europe and Australia. Most of the complaints stem from the US where the GTI only has direct injection (my understanding anyway)

 

The crankcase emissions (and exhaust gas recycling) are fed back into the inlet port to reduce pollution and I believe this is the source of the problem especially if you do a lot of cold starts and short runs as I do.

Some people have fitted 'catch cans' to collect the crud and while the resulting collection is impressive, I don't know how effective they are at reducing the actual carbon build up.

Others recommend a frequent Italian service, give it some revs to dislodge the carbon, again I don't know how effective that is but at least it is fun.

 

I expect my car may need some attention for this problem when it gets to about 40k km but current performance and economy suggests there are no issues at 20k km.

Edited 27 January, 201610 yr by Gerrycan

Others recommend a frequent Italian service, give it some revs to dislodge the carbon, again I don't know how effective that is but at least it is fun.

Oh well, I don't see I'll be having that issue then ! 

 

Regards

T

 

 

The crankcase emissions (and exhaust gas recycling) are fed back into the inlet port to reduce pollution and I believe this is the source of the problem especially if you do a lot of cold starts and short runs as I do.

Some people have fitted 'catch cans' to collect the crud and while the resulting collection is impressive, I don't know how effective they are at reducing the actual carbon build up.

Others recommend a frequent Italian service, give it some revs to dislodge the carbon, again I don't know how effective that is but at least it is fun.

 

I expect my car may need some attention for this problem when it gets to about 40k km but current performance and economy suggests there are no issues at 20k km.

According to VW, you need to maintain a minimum 4000rpm for at least 20 minutes to get sufficient heat into the valve stems.  This will help burn off carbon.  I have no idea if it works or not.

 

The traditional Italian tune up of blurting around the back streets near the workshop a few times won't help the valves at all.

 

Just out of curiosity. Would using a couple of shots of either Redex or Miller's Petrol Ecomax do any good?

On a DI engine it won't help the inlet valves. 

Hmm does not sound good for 1.4tsi engines, you would think they would design engines to address these known flaws

Not really, remember the solution to the DMF problem was, and in some cases still is, 'what problem, never came across that before', the solution to the DPF problem 'what problem, only happens if you drive wrong'.

 

It does of course become more difficult to address a problem if you focus your energies on pretending it doesn't exist.

 

VAG far from the only culprits.

 

My own perspective is that I intentionally got one of the last 1.9 PD engines without DPF (Skoda salesman really could not understand why this was a priority) but got caught out with the DMF - eventually managed to get SMF under warranty.