Consumer Reports - Direct Injection engines having reliability problem

[WendysOrBust]

 

It has been touted as the automotive holy grail, the ultimate marriage of better performance and greater fuel economy. It’s the direct-injection (DI) engine, the latest technology designed to squeeze more mpg out of cars. And it has actually been delivering results.

 

For example, the Mazda3’s combined fuel economy jumped from 28 mpg in 2010 to 32 mpg in 2012 in our testing of the new Skyactiv engine. Other automakers have been using direct injection to add horsepower—the Cadillac CTS, for example, gained 34 hp—without any sacrifice in fuel economy.

Though direct injection is currently seen mostly on luxury vehicles or on mainstream cars as a higher-trim option (priced anywhere from a few hundred dollars to a couple of thousand), it could soon be within the means of more drivers as costs continue to come down.

But those engines are also having reliability problems, something that automakers are trying to keep quiet.

Not surprisingly, a number of readers have asked us about direct injection. Take Anestis Halkidis of North Kingstown, R.I.:

“I have a 2006 VW GLI with the 2.0T FSI engine with direct injection,” he wrote. “At around 80,000 miles, I went to the VW dealer to diagnose a check-engine light. It turns out that the intake valves had to be cleaned due to carbon deposits that were causing drivability issues.”

When his dealer failed to offer free work or any compensation, Halkidis took his car to a local VW shop that cleaned the valves by blasting them with walnut shells. (Yes, walnut shells; it’s a method used by BMW.) The cost to Halkidis was about $400.

So what’s up with direct injection?

First, a primer on how it works: By injecting gas­oline at high pressure directly into the engine’s combustion chamber, direct injection more precisely measures fuel than conventional fuel-injection systems or old-time carburetors.

The result is more complete combustion and cooler cylinder temperatures that enable a higher compression ratio for greater efficiency and power. Engine technology supplier Bosch says that direct injection can return a 15 percent gain in fuel economy while boosting low-end torque as much as 50 percent.

Combining direct injection with other technologies—such as turbocharging—can deliver even greater gains in economy and performance. That in turn enables carmakers to use smaller displacement engines, resulting in an efficiency snowball effect. Many automakers are marketing DI as pro­viding fuel economy that’s almost as good as a hybrid’s, and with better performance—but without the $4,000 hybrid premium.

Although the breakthrough seems like a dream come true, an unwanted side effect has been emerging. Letter writers have complained to Consumer Reports and the National Highway Traffic Safety Administration (NHTSA) that over time DI can lead to clogged fuel systems and engine carbon buildup. The result can be engine hesitation and a loss of power—and the need for expensive repairs.

Some carmakers, including BMW and Kia, have issued technical service bulletins (TSBs) to their dealers recommending that drivers use only name-brand detergent gasoline—without ethanol additives—and that they periodically add a fuel-system cleaner when they refuel. (A TSB is an alert that the automaker sends to dealers to warn about ongoing problems with individual models and how to fix them. It may allow dealers to make repairs at little or no cost to the customer as a goodwill gesture.)

Other automakers have devised an engineering fix that works while the car is oper­ating. It involves modifying the engine to spray a small amount of fuel directly onto the valves to help keep them clean.

It’s important to note that not all cars with direct injection experience long-term problems. But if your engine stumbles more than it used to, or it suddenly lacks power, ask your dealer about it. A fix may be available, and you may not have to pay for it.

This article also appeared in the February 2015 issue of Consumer Reports magazine.

https://autos.yahoo.com/news/direct-injection-engines-improve-performance-save-fuel-price-193000698.html

 

Not exactly sure what BMW and Kia is doing suggesting adding fuel cleaner or running "brand name fuel" The issue here is that fuel itself is not getting on the valves thus keeping them "clean" Adding fuel cleaners will not stop carbon build up on the valves, which more than likely is oil coming from the PCV system.

 

Below are some images from member Gone_Fishing which you can see more off in the thread below. He says during the intake removal the engine only had 30,000 miles on it.

 

http://www.gm-trucks.com/forums/topic/168709-intake-manifold-off-with-pics-of-intake-valves-with-deposits/

 

 

 

 

 

 

 

Might be a good time to start looking at preventative maintenance. If left unchecked fuel milage and performance will greatly suffer.

[bills]

Good info!

[newdude]

A couple of the OEMs (Toyota I think is one for sure) have gone to a dual injection system. Indirect (multiport) and direct injection both on an engine. Keeps the valves clean but delivers on power hikes.

[kstruckcountry]

A couple of the OEMs (Toyota I think is one for sure) have gone to a dual injection system. Indirect (multiport) and direct injection both on an engine. Keeps the valves clean but delivers on power hikes.

Mazda as well I think.

[crushNchowda]

great...so we're F'd is what you're saying?

[darkfox1]

From looking at those pics it reminds me of the back of any LSx throttle body after a year or so of driving. The back of the TB on an Lsx will be FILTHY because of the EGR behind it, and they will eventually gum and stick, so I'd say its a fair assessment.

 

This is easy to clean if you can get to it but my thought is.. how do I hose it down with gumout without cycling that mess through my engine? Take off the heads? That's a pricey 80k mile tuneup!

 

That being said.. eh.. I'll take my chances. If I still have the truck at 80k miles I'll complain about it then.

 

Also, any auto manufacturer in this day n age expecting us to run ethanol free gasoline has their head somewhere where the sun doesn't shine. You can't sell a car in the us with the corn lobby and expect to reliably find ethanol free gas. I've seen ONE station that doesn't have ethanol, and it's pricey.

[chevy2tuff2006]

Hense the oil can thread in the engine section....get one it will solve this problem

[Cowpie]

This is one of the biggest reasons that many are putting on PCV line catch can / filter systems. To greatly reduce the contaminates that get in the intake and cause these problems. Simple, cost effective, pro active measure. Too bad that those of us who did not even have a DI engine had this figured out a long, long time ago. Thanks CR for finally arriving to the party.

[BigBadSierra]

GM has delt with this they sprays the fuel on an angle while the valves are down.

 

Thus washing them.

 

The only draw back is small amounts of oil make it back up and ends up by your throttle body. This is where it comes from.

 

This is also why running fuel injector cleaner helps.

 

https://www.youtube.com/watch?v=qd90yHlmfS4

[Stoddard]

My question is are the catch cans proven to fix this? If so why don't they provide them for all these engines vs. giving out tsb's that say to use top tier gas and having techs clean the intakes and valves??? I thought the original application for the catch cans was to fix oil consumption through pcv loss?

[WendysOrBust]

I think catch cans will help with most of the carbon build up issues. I honestly had never thought of one but might start looking into it if I plan on owning the vehicle long term. Just be careful with your catch can, if you disrupt the pressure you might damage your drain pan gasket like the guy with his Ram Ecodiesel did.

 

 

 

Basically the new lines he ran to the catch can were the incorrect size thus creating too much pressure in the oil system causing a gasket to go out.

 

Another good preventative maintenance is to do apply Seafoam engine cleaner directly into the throttle body as seen below.

 

https://www.youtube.com/watch?v=Vqs8QWvssmg

 

Might be worth it to begin doing one or two things now to ensure valves stay clean down the road. Will be easier than waiting till 50k miles or more than begin doing any of the above.

[WendysOrBust]

great...so we're F'd is what you're saying?

No, not necessarily. Its important to know any issues will harm power and milage down the road. In the big scheme of things this is a relatively easy issue to maintain.

[SMiller]

A catch can is going to get about 80% of it, that should help a ton!

 

Direct injection is killing the EcoBoost, having the dealer remove the heads to clean the valves is costly, what happens when its your truck and you are out of warranty...

[Stoddard]

But I'm asking for evidence that this actually helps. Yes it does catch oil. We can see this. Has anyone had one on long term since new??? I don't buy snake oil gimmicks unless its proven.

[Silverado-Hareek]

GM has delt with this they sprays the fuel on an angle while the valves are down.

 

Thus washing them.

 

The only draw back is small amounts of oil make it back up and ends up by your throttle body. This is where it comes from.

 

This is also why running fuel injector cleaner helps.

 

https://www.youtube.com/watch?v=qd90yHlmfS4

 

Sorry man but this information you've stated is incorrect. The oil in the throttle body is not from back up as you describe it's from the PCV system. GM hasn't fixed this issue at all. They've attempted to address it by trying to add baffles that trap some of the oil before it gets to the valves but this has been proven not to work 100%. Another user has posted a thread with his valve covers removed on his 2014 silverado and he posted pictures of significant carbon buildup on his valves at only 20,000 miles. Toyota is the only manufacturer I know of that has addressed this and apparently Mazda according to this thread. Unless you have one of their engines, you will need an oil catch can to prevent the build-up on the valves from happening.