Possible Direct-Injection Issues
#1
01-08-2015, 01:56 PM
Possible Direct-Injection Issues
I have provided below an article in the February 2015 issue of Consumer Reports, concerning possible future problems with our new direct-injection engines. It's a worthwhile read and may help us prevent drivability issues down the road.
Dennis
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 Mazda 3'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 on mostly 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, Haldikis took his car to a local VW shop that cleaned the valves with walnut shells. (Yes, walnut shells; it's a method used by BMW.) The cost to Haldikis 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, Honda, 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. (S 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 use to, or it suddenly lakes power, ask your dealer about it. A fix may be available, and you may not have to pay for it.
Dennis
Better MPG …
But at a PriceDirect-injection engines improve performance and save fuel,
But you may spend more time in the repair shopFor example, the Mazda 3'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 on mostly 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, Haldikis took his car to a local VW shop that cleaned the valves with walnut shells. (Yes, walnut shells; it's a method used by BMW.) The cost to Haldikis 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, Honda, 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. (S 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 use to, or it suddenly lakes power, ask your dealer about it. A fix may be available, and you may not have to pay for it.
#2
01-08-2015, 02:45 PM
Sounds like a generic article. All of it is true though. The buildup of carbon is called coking. Normally the ECM will run the engine rich when cold or preset intervalto "wash off" any built up carbon. Adding fuel injector cleaner on recommended intervals can help to prevent this as well.
I myself always run mid grade 89 fuel, seems to have a better performance result than 87. I have an occasional minor stumble, but no bucking, hesitation, or stalling. This has been discussed before but I find 89 to be a more reliable blend than 87. using 91 or 93 blend yields no noticeable improvement.
I myself always run mid grade 89 fuel, seems to have a better performance result than 87. I have an occasional minor stumble, but no bucking, hesitation, or stalling. This has been discussed before but I find 89 to be a more reliable blend than 87. using 91 or 93 blend yields no noticeable improvement.
#3
01-08-2015, 02:46 PM
My TDI ("turbo direct injection") '00 New Beetle had 219,000 miles on it when I sold it (at a premium because it was in excellent condition). No issues with coking up at all. Don't know if this applies to gasoline DI engines, but the TDI loved and needed to be run hard from time to time.
es
es
#4
01-08-2015, 03:00 PM
I have provided below an article in the February 2015 issue of Consumer Reports, concerning possible future problems with our new direct-injection engines. It's a worthwhile read and may help us prevent drivability issues down the road.
Dennis
DI can lead to clogged fuel systems and engine carbon buildup.
Some carmakers, including BMW, Honda, 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.
Dennis
DI can lead to clogged fuel systems and engine carbon buildup.
Some carmakers, including BMW, Honda, 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.
2. How does name-brand detergent gasoline would prevent the intake valve contamination issue on direct injection engine in which the fuel is directly spraying into the combustion chamber?
3. In the U.S., who sells straight gasoline without ethanol?
#5
01-08-2015, 03:18 PM
1. Intake air is always dirty even with air filters. The less amount of fuel being injected creates a harder environment for the fuel to wash away these deposits. This has been known for decades about this tech. Various fuel detergents are formulated to remove these deposits if added to the fuel on recommended intervals.
2. Not all fuels are created equal. Some have more impurities than others. Another consideration is how dirty the air filter element is. Less liquid fuel and with impurities means less liquid to wash away or pass through the engine easier. Think of washing you hands with hand soap but with little to no water, a soap residue builds up on your hands that cannot be washed away right? Same principle applies here.
3. When you find this out, you let me know k?
2. Not all fuels are created equal. Some have more impurities than others. Another consideration is how dirty the air filter element is. Less liquid fuel and with impurities means less liquid to wash away or pass through the engine easier. Think of washing you hands with hand soap but with little to no water, a soap residue builds up on your hands that cannot be washed away right? Same principle applies here.
3. When you find this out, you let me know k?
#6
01-08-2015, 03:34 PM
Great Article About GDI Deposits
MOTOR Magazine - December 2014 - Page: 36
Tons of info here.
What I got from this...
1) Use top tier gas always.
2) Using synthetic oil helps prevent wear with the GDI high pressure pump.
Tons of info here.
What I got from this...
1) Use top tier gas always.
2) Using synthetic oil helps prevent wear with the GDI high pressure pump.
#7
01-08-2015, 03:36 PM
1. Intake air is always dirty even with air filters. The less amount of fuel being injected creates a harder environment for the fuel to wash away these deposits. This has been known for decades about this tech. Various fuel detergents are formulated to remove these deposits if added to the fuel on recommended intervals.
2. Not all fuels are created equal. Some have more impurities than others. Another consideration is how dirty the air filter element is. Less liquid fuel and with impurities means less liquid to wash away or pass through the engine easier. Think of washing you hands with hand soap but with little to no water, a soap residue builds up on your hands that cannot be washed away right? Same principle applies here.
The main cause of the intake contamination on D.I. engine is WHERE the fuel is injected, not so much how much fuel or what's in the fuel.
You can dump all the fuel you want with the best detergent available DIRECTLY into the combustion chamber. Still there is no way you can clean the intake valves/stems that would be sticking due to contamination.
3. When you find this out, you let me know k?
> I asked first!
2. Not all fuels are created equal. Some have more impurities than others. Another consideration is how dirty the air filter element is. Less liquid fuel and with impurities means less liquid to wash away or pass through the engine easier. Think of washing you hands with hand soap but with little to no water, a soap residue builds up on your hands that cannot be washed away right? Same principle applies here.
The main cause of the intake contamination on D.I. engine is WHERE the fuel is injected, not so much how much fuel or what's in the fuel.
You can dump all the fuel you want with the best detergent available DIRECTLY into the combustion chamber. Still there is no way you can clean the intake valves/stems that would be sticking due to contamination.
3. When you find this out, you let me know k?
> I asked first!
#8
01-08-2015, 04:09 PM
In reverse order:
3) Ethanol-free gas stations in the U.S. and Canada
2) Gasoline detergents will also help keep the injectors clean, regardless whether they are in a manifold or in the combustion chamber. There's a benefit, in other words.
1) I don't think the issue is with DI, actually. As stated above, a DI system is injecting directly into the combustion chamber (downstream of the valve stem area). Where I do think the problem is is a combination of that fact (vaporized detergent gasoline is not flowing past the backside of the valve face, thus keeping it clean) and of the fact that your engine extracts crankcase vapors (your "PCV valve") and pumps them back into the intake manifold, where the oil vapor can build up ("coke up") both in the manifold and on the valve stems. The TDI engine in my NB was notorious for doing this, and there were numerous hacks posted online on how to disconnect the system or clean out the intake if/when it got coked up.
We'll need some folks to get some higher miles on the engine and see if anything like this will be a problem long-term…
es
3) Ethanol-free gas stations in the U.S. and Canada
2) Gasoline detergents will also help keep the injectors clean, regardless whether they are in a manifold or in the combustion chamber. There's a benefit, in other words.
1) I don't think the issue is with DI, actually. As stated above, a DI system is injecting directly into the combustion chamber (downstream of the valve stem area). Where I do think the problem is is a combination of that fact (vaporized detergent gasoline is not flowing past the backside of the valve face, thus keeping it clean) and of the fact that your engine extracts crankcase vapors (your "PCV valve") and pumps them back into the intake manifold, where the oil vapor can build up ("coke up") both in the manifold and on the valve stems. The TDI engine in my NB was notorious for doing this, and there were numerous hacks posted online on how to disconnect the system or clean out the intake if/when it got coked up.
We'll need some folks to get some higher miles on the engine and see if anything like this will be a problem long-term…
es
#9
01-08-2015, 05:40 PM
As I've said in another thread with a similar topic to this one, when I had my Hyundai Genesis, this seemed to be a problem that would eventually be caused.
The "easy fix" a lot of people used is an oil catch can on the line between the crank case and the intake manifold. The oil deposits out on a screen and is emptied on a maintenance interval. Does it help much? Can't say. But some folks (especially the 2L turbo guys) showed the quantities of oil they were pulling from their cans to be somewhat significant (1-4fl oz per oil change).
Taking the manifold off my Genesis at 30k miles revealed an extremely light coat of oil that barely even gave off a sheen; would it be a problem at 100k? I couldn't say for certain. But I noticed no performance issues for the time I had the car.
The "easy fix" a lot of people used is an oil catch can on the line between the crank case and the intake manifold. The oil deposits out on a screen and is emptied on a maintenance interval. Does it help much? Can't say. But some folks (especially the 2L turbo guys) showed the quantities of oil they were pulling from their cans to be somewhat significant (1-4fl oz per oil change).
Taking the manifold off my Genesis at 30k miles revealed an extremely light coat of oil that barely even gave off a sheen; would it be a problem at 100k? I couldn't say for certain. But I noticed no performance issues for the time I had the car.
#12
01-08-2015, 11:03 PM
Unless you trade your cars in soon as the warranty runs out then that wont always be true. This is about the future of the car as it ages.
#14
01-09-2015, 09:45 AM
Most of this is all BS. It comes down to hype and scare tactics. Direct injection is a new fangled technology that most main stream pubact know nothing about. They are always leery or distrust or scared of something they are not familar with.
Now there is propaganda and fears in general over many makes of vehicles that this direct injection is somehow flawed and unreliable and unproven.
Direct injection is a technology borrowed from diesel engines. It simply involves a fuel pump injecting fuel directly into the cylinder at tremendously high pressure. It is technology directly adapted from diesel.
I make the argument that direct injection is probably a better and more reliable fuel delivery system than anything we ever had before in automobile industry.
A diesel engine is no doubt more reliable than a gasoline engine. BMW, VW, Honda, know how to make a diesel engine and make them well and make some of the best. Honda uses diesel engines in many vehicles in overseas markets. Including the FIT.
Direct injection diesel engines have been around for 20yrs. It's finally been adapted to automobiles. It's be slow in coming because a high pressure direct injection fuel pump adds significant cost to a gasoline engine. It's a big reason why a diesel is a pricey option on anything.
Direct injection is more fuel efficient. It also makes diesel and gasoline engines much more easier to start in extreme cold. I own a compact JD tractor with a diesel with direct injection. It will start at -20F no problem what so ever.
Now there is propaganda and fears in general over many makes of vehicles that this direct injection is somehow flawed and unreliable and unproven.
Direct injection is a technology borrowed from diesel engines. It simply involves a fuel pump injecting fuel directly into the cylinder at tremendously high pressure. It is technology directly adapted from diesel.
I make the argument that direct injection is probably a better and more reliable fuel delivery system than anything we ever had before in automobile industry.
A diesel engine is no doubt more reliable than a gasoline engine. BMW, VW, Honda, know how to make a diesel engine and make them well and make some of the best. Honda uses diesel engines in many vehicles in overseas markets. Including the FIT.
Direct injection diesel engines have been around for 20yrs. It's finally been adapted to automobiles. It's be slow in coming because a high pressure direct injection fuel pump adds significant cost to a gasoline engine. It's a big reason why a diesel is a pricey option on anything.
Direct injection is more fuel efficient. It also makes diesel and gasoline engines much more easier to start in extreme cold. I own a compact JD tractor with a diesel with direct injection. It will start at -20F no problem what so ever.
Last edited by cuemark8; 01-09-2015 at 09:59 AM.
#15
01-09-2015, 10:45 AM
I read the report. It makes one mentioned of customer and a problem. Sounds to me like he somewhere along the line purchased some crappy fuel.
It make note in the article it was suggested by automakers to use a quality brand name fuel. Gee, that's nothing new. Been that way forever! Read the fine print in your owner's manual. I bet it says somewhere to use a quality brand name fuel.
One negative way to look at direct injection is engine cost. Diesel engines are expensive because of high pressure fuel pumps. Diesel engines usually have turbo or multiple turbos. This added alot of cost over a gasoline engine.
Now we have many direct injection gasoline and turbo charged engines being the norm in automobile use. Now we a gasoline engine just as expensive as a diesel engine without nearly the fuel economy or reliability of a diesel engine! Yay!
It make note in the article it was suggested by automakers to use a quality brand name fuel. Gee, that's nothing new. Been that way forever! Read the fine print in your owner's manual. I bet it says somewhere to use a quality brand name fuel.
One negative way to look at direct injection is engine cost. Diesel engines are expensive because of high pressure fuel pumps. Diesel engines usually have turbo or multiple turbos. This added alot of cost over a gasoline engine.
Now we have many direct injection gasoline and turbo charged engines being the norm in automobile use. Now we a gasoline engine just as expensive as a diesel engine without nearly the fuel economy or reliability of a diesel engine! Yay!
#16
01-09-2015, 10:55 AM
I read the report. It makes one mentioned of customer and a problem. Sounds to me like he somewhere along the line purchased some crappy fuel.
It make note in the article it was suggested by automakers to use a quality brand name fuel. Gee, that's nothing new. Been that way forever! Read the fine print in your owner's manual. I bet it says somewhere to use a quality brand name fuel.
One negative way to look at direct injection is engine cost. Diesel engines are expensive because of high pressure fuel pumps. Diesel engines usually have turbo or multiple turbos. This added alot of cost over a gasoline engine.
Now we have many direct injection gasoline and turbo charged engines being the norm in automobile use. Now we a gasoline engine just as expensive as a diesel engine without nearly the fuel economy or reliability of a diesel engine! Yay!
It make note in the article it was suggested by automakers to use a quality brand name fuel. Gee, that's nothing new. Been that way forever! Read the fine print in your owner's manual. I bet it says somewhere to use a quality brand name fuel.
One negative way to look at direct injection is engine cost. Diesel engines are expensive because of high pressure fuel pumps. Diesel engines usually have turbo or multiple turbos. This added alot of cost over a gasoline engine.
Now we have many direct injection gasoline and turbo charged engines being the norm in automobile use. Now we a gasoline engine just as expensive as a diesel engine without nearly the fuel economy or reliability of a diesel engine! Yay!
#17
01-09-2015, 11:27 AM
Some carmakers, including BMW, Honda, 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. (S 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.
Ok, back to the article. Above was the suggested fix. Or should I say simple methods to avoid possible future repairs.
I do all of those! Except maybe avoid ethanol. Hard to do! Thank our fine government for that.
I always buy a brand name fuel. I do occasionally add a fuel system cleaner every so often.
So what other fix was there? I read the article and reproduced it here. And quoted advice and suggestions from the automakers.
Ok, back to the article. Above was the suggested fix. Or should I say simple methods to avoid possible future repairs.
I do all of those! Except maybe avoid ethanol. Hard to do! Thank our fine government for that.
I always buy a brand name fuel. I do occasionally add a fuel system cleaner every so often.
So what other fix was there? I read the article and reproduced it here. And quoted advice and suggestions from the automakers.
#18
01-09-2015, 11:44 AM
I own a JD tractor that is diesel. I am mechanically inclined and service my vehicles myself and service the tractor myself. I understand how a diesel engine works and they have been direct injection for a very long time. Decades! I never heard of a problem with them.
Most diesels are turbo charged. Maybe the turbo charging helps keep the valves clean? If normal atmospheric pressure is allowing oil and gunk to build up on the valves. Having a pressurised stream is air is enough to blow it off of there and keep it from building up.
Most diesels are turbo charged. Maybe the turbo charging helps keep the valves clean? If normal atmospheric pressure is allowing oil and gunk to build up on the valves. Having a pressurised stream is air is enough to blow it off of there and keep it from building up.
#19
01-09-2015, 11:46 AM
Ok, back to the article. Above was the suggested fix. Or should I say simple methods to avoid possible future repairs.
I do all of those! Except maybe avoid ethanol. Hard to do! Thank our fine government for that.
I always buy a brand name fuel. I do occasionally add a fuel system cleaner every so often.
The contamination of intake system occurs at the upper stream of the combustion chamber. Using non ethanol fuel or adding fuely system cleaner (to the fuel tank) ain't gonna clean it because the DI engine injects fuel directly into the combustion chamber. That's the biggest the downfall of the DI system - contamination occuring in the area where fuel is not passing through anymore.
Last edited by Chazman; 01-09-2015 at 11:53 AM.
#20
01-09-2015, 01:01 PM
Yeah, there's a bit of misunderstanding of how DI systems work in this thread. The buildup can't be cleaned by fuel, because the fuel never touches the valves. On Toyota's DI engines they have auxiliary injectors that fire occasionally to keep the valves clean.
On BMW and VW DI systems there is a long history of problems with this, so it's not just "BS". Cleaning requires a teardown of the head and physically cleaning the valves with a variety of methods, which is costly.
Improved EGR/PCV systems can mitigate most of the issues, and I think Honda did their homework on this on the Earth Dreams motors, or so that's what i've gathered online.
Diesel motors do not have PCV or EGR systems afaik, they're not required, so no problems there.
I do think there will be additional maintenance costs for the DI motors, but not nearly as bad as the older designs by VW and BMW... maybe not for 150k-200k, maybe never? Like has been said, the Accords seem to be doing just fine.
On BMW and VW DI systems there is a long history of problems with this, so it's not just "BS". Cleaning requires a teardown of the head and physically cleaning the valves with a variety of methods, which is costly.
Improved EGR/PCV systems can mitigate most of the issues, and I think Honda did their homework on this on the Earth Dreams motors, or so that's what i've gathered online.
Diesel motors do not have PCV or EGR systems afaik, they're not required, so no problems there.
I do think there will be additional maintenance costs for the DI motors, but not nearly as bad as the older designs by VW and BMW... maybe not for 150k-200k, maybe never? Like has been said, the Accords seem to be doing just fine.