Direct Injection Issues

[Mr Pig]

I'm reading about the carbon build-up on valves in direct injection engines. These things have been in the field for a while now. Is it still an issue? Is it still something to watch for? If so, watch for what exactly??

Are they better these days? Have they sorted them out?

I'm interested because we now have three of them in the family!

Thank you.

 

[Invertigo]

The issue with carbon buildup was due to engines being direct injection only and the PCV recirculating oil vapour into the intake - on port injection the fuel would wash this vapour from the valves into the combusion chamber whereas direc injection engines add the fuel directly into the cylinder.

I believe around 2017 (dont quote me on that) VW redesigned their engines to use both direct and port injection (as most manufacturers have now too) to aleviate the issue - the DI is used primarily with the PI activated at set intervals to wash off any residues on the intake valves.

 

[Mr Pig]

We have a 2016 1.2, a 2016 1.4 and a 2017 1.0. So unfixed then? :0(

 

[Invertigo]

Ah, less sure on them, I was more referring to the EA888 engine in the Cupra models. Believe the 1.0 and 1.4 will both be the EA211 engine platform, whereas the 1.2 is the EA111. Both of these engines are DI only.

I expect a lot of it is blown out of proportion mind, I had a Mini Cooper S a few years back that has the same issues, its recommended to have the intake walnut blasted every 40-50k miles or so, so its not a big deal. I had mine done at 40k and the valves, while certainly dirty, weren't bad at all. Just think of it as a £200 additional servicing cost every 50k miles.

 

[RUM4MO]

Certainly the later EA888 engines in Cupras seem to have lost their port injectors, so that plan did not last long.

The 2016 1.2 16V engine will be a EA211 and the 2017 1.0 ?V engine will be newer than EA211 family I'd think - if it matters, I sort of hoped that the newer 1.0 ?V engines would have been fitted with port injection, maybe not.

 

[Invertigo]

Certainly the later EA888 engines in Cupras seem to have lost their port injectors, so that plan did not last long.

The 2016 1.2 16V engine will be a EA211 and the 2017 1.0 ?V engine will be newer than EA211 family I'd think - if it matters, I sort of hoped that the newer 1.0 ?V engines would have been fitted with port injection, maybe not.

Strange, can't see any further documented changes after the Gen3 revision that introduced the multi point injection on the EA888. I know that the US market never got the MPI as part of the upgrade, but then the Cupra isn't sold over there anyway. The 1.0 EA211 was introduced in 2015, can't see why it would be changed again before 2017?

 

[Mikertroid]

My 10 year old 325i has direct injection. I've done 100 of its 150k miles Three of the 6 injectors were changed early on under warranty before I took ownership. It rarely does short journeys but I've had no problems with them on that car. Hopefully my new EA888 Will run as well as that engine.

Coil packs however.......

 

[Mr Pig]

So if you do get a build up, how do you know? My new car, the 16-plate 1.4 act, has a lumpy tickover sometimes. I just assumed it was normal but I've read that coked up valves can cause that. Car has 40K on it.

I'd rather keep ahead of this than wait until there is a serous problem.

 

[Invertigo]

Rough running is certainly a symptom. As I mentioned above, consider getting the intake 'walnut blasted' every 40-50k, its the only way to really clean anything off. Don't believe these other products that claim do clean the engine out with just some smoke blown into the intake, walnut blasting is a physical cleaning using walnut shells (hard enough to break away carbon deposits, soft enough to not damage or score the metal in any way)

I'd call round a few local specialists and see what they charge. VW and BMW are the 2 main culprits in my experience so someone who specialises in either may well have a walnut blasting machine.

 

[r@d00]

Strange, can't see any further documented changes after the Gen3 revision that introduced the multi point injection on the EA888. I know that the US market never got the MPI as part of the upgrade, but then the Cupra isn't sold over there anyway.

VW introduced the port injection for the European market in order to pass the Euro 6 emission rules, not to solve a customer problem (carbon build-up). That was a collateral benefit... This is why the US market never got the MPI.

After WLTP rules in September 2018, they were forced to add GPFs to the exhaust system and the port injection was not needed anymore to lower the emissions, so they took it out

I have a post WLTP Cupra 2019 and only have the direct injection unfortunately...

 

[Invertigo]

That sounds about right, minimise costs in any way possible at the possiblilty of having to pay for the rare high mileage engine to be cleaned out under warranty. Ah well!

 

[Mr Pig]

Anyone suffered any damage due to this issue? Apart from the lumpy idle, what else should I keep an eye out for?

 

[Rooster]

Mine gets an annual "treat" on the German Autobahn!

 

[SRGTD]

Apart from the lumpy idle, what else should I keep an eye out for?

Removal of Port Injection on the Golf R was something that was discussed at length over on VWROC.com early this year. Typical potential symptoms of carbon build up in direct injection engines that were highlighted were poor fuel efficiency, cold start misfires and a general drop in power and poor running.

Interestingly, the current model Polo GTI with a 2.0 litre 200ps EA888 (gen 3b) engine has retained dual injection - confirmed by owners over on uk-polos.net who have checked under the engine cover and the port injection components (port injector fuel rail, port injector loom connector and fuel pressure sensor) are present.

 

[Dannnnn]

My previous car (BMW 335i - N54) was direct injection.
The way to tell if it needed doing was generally a rough idle.

I paid a specialist £280 to do mine and it improved the idle a tiny tiny bit but I didn't see any difference in economy or performance (@60k miles)

Having the buildup of carbon won't create any issues apart from a slightly rougher idle (if that's even noticeable)

On my BMW before:

After:

 

[Mr Pig]

Having the buildup of carbon won't create any issues apart from a slightly rougher idle...

I've read that it can cause the valves to overheat and fail as the deposits impede cooling.

I doubt thrashing it on the autobahn would make any difference. Besides, you don't need to go fast, just change up less!

 

[Mr Pig]

Can't you just disable the PCV system, the crap into the air like we used to do, and most of the problem will disappear?

 

[cupra14]

No, but in any case some of the carbon can be deposited as exhaust gases swirl around, I gather. (Things never quite behave as intended.)

 

[cupra14]

Thinking more... you could add an oil catch can.

 

[Dannnnn]

Catch cans help but don't stop the issue.
Normal cars don't get the problem as the fuel washes over the valves and keeps them clean, DI gets rid of the fuel wash.

The only actual way to 100% stop it is port injection.