Shakin my head…

Today’s vehicles without a doubt are an incredible technological marvel. You have antilock brake systems, traction control systems, air bag systems, collision avoidance systems, systems that will park the vehicle for you. The list goes on and on.

Most manufactures didn’t just “volunteer” to invent this stuff. Most if not all were mandated by the federal government to make cars safer and increase fuel economy while reducing emissions.

 

Lets take fuel economy for instance. Right now in 2017 the EPA is expecting a 34.1 MPG average. What this means is a manufactures, lets use GM for example has to have a corporate air fuel economy of 34.1 MPG. If this goal is not met they pay a hefty fine.
Now this is not to say that every vehicle they sell today has to get 34.1 MPG. What this means is ALL the vehicles the sell in a give year all combined together and divided by the total amount has to achieve the 34.1 MPG average.

 

So if GM sells lots of trucks that get only 30 MPG, they have to sell lots of little cars that get 40MPG so the end result is the 34.1 MPG average. Otherwise they get fined. There is also an element of reducing tail pipe emissions they are dealing with but that’s a hole other subject best suited for another day.

 

Getting back to the fuel economy issue I really do have to tip my hat to the auto makers. It’s a do or die situation for them. If they can’t comply they could potentially be put out of business. I can’t even imagine being put under that pressure.

 

I’m gonna shift gears here for a moment and talk about something. There is a flip side or a downside if you will to what is going on in the automotive industry. In order to the fuel economy up, auto makers are designing engines that are far more different than anything we have ever seen before. This new technology has its drawbacks. Especially for consumers.

 

The two big main differences we are seeing are internal engine sludge and carbon build up. In order to get the fuel economy up and the emissions lower, the auto makers have designed into their engines such things as variable valve timing, low tension oil piston rings and GDI “gasoline direct injection” fuel systems.

 

These engineering marvels work fantastic when they work, but unfortunately they have to be maintained or the screw up and they can screw up bad when they do.

 

Have you ever read your owners manual? How often are you supposed to do an oil change? every 7500 miles, 10,000 miles or even more? This is the problem. Not doing an oil change every 3000, to 3500 miles and ADDING an internal engine conditioner on every oil change (About every 3500 miles) AND adding a fuel injection cleaner, and an oil additive also about every 10,000 miles to keep it clean and running smoothly can and will break your car. Not to mention while ALSO keeping you from ruining the catalytic converter, (A very expensive part).

 

If you were to Google “the problems with GDI engines” you will come across pages and pages of problems the auto makers are having trying to fix this mess of a problem. Trying to comply with the federal government standards is not easy. I feel sorry for them actually.

 

Here is just one article I copied from a google search. It is a great article by Andrew Bell.

 

Ask An Engineer: GDI Problems In A Nutshell
By Andrew Bell on May 3, 2012

“Ask an Engineer” is hosted by Andrew Bell, a mechanical engineer and car enthusiast. Andrew has his MASc in Mechanical Engineering from the University of Toronto, and has worked on Formula SAE teams, as well as alternative fuel technologies in Denmark and Canada. Andrew’s column will explore engineering topics in the most accessible manner possible.

 

Even though every other car nowadays seems to offer gasoline direct injection (GDI), Mercedes-Benz was the first to exploit this technology in the 1955 300SL. But it wasn’t until the mid-1990’s that other automakers started to use GDI in mass produced vehicles. GDI promises marginal increases in fuel economy (3% reduction in BSFC ) but its real benefits include reduced cold start/low load emissions and higher power outputs. While the technology offers engineers incredible flexibility from an engine design perspective, it is not without faults. As with any new technology it is important to understand both the positives and negatives before you choose, say a compact car with GDI or one regular fuel injection. If you want to keep your car for a long period of time, the long-term reliability of a GDI engine is an important factor.
The effect of increased percentages of ethanol on injector longevity.

 

The percentage of ethanol in gasoline at the pumps is steadily increasing. Ethanol has a tendency to increase the corrosion rate of the various metals used in an engine. Add this to the elevated fuel pressure and the fact the injector is directly exposed to in-cylinder combustion events, and you have a recipe for a recall. Furthermore, these injectors are very sensitive to fuel quality due to outrageously tight tolerances. It is very important to use high quality fuels and keep the filters clean.
Higher pressures in general.

 

GDI requires significantly higher fuel inlet pressures than port injection. This puts a great deal of strain on every piece of the fuel delivery chain. This is not a problem on a new engine. 50,000 miles down the road, and it may be. Manufacturers have been relatively proactive in this department by specifying robust, stainless steel fuel lines and connections. That hasn’t stopped fuel pump recalls from already occurring
Carbon buildup on intake valves.

 

This is the big problem with most current GDI engines. Due to modern unburned hydrocarbon (UHC) regulations, vapors from the crankcase are usually vented into the intake stream in order to prevent oil droplets from escaping through the exhaust. In a port injection engine, these droplets are ‘washed off’ the neck of the intake valve by a relatively constant stream of gasoline droplets. In a GDI engine, the gasoline doesn’t touch intake side of the valve. As a result, the droplets have a tendency to bake onto the valve and significantly reduce performance. To add to this effect, many advanced GDI engines also include exhaust gas recirculation in order to lean out the combustion mixture and reduce in-cylinder temperatures for certain combustion modes (reducing NOx emissions). Since GDI combustion has the ability to produce far more soot than premixed combustion (port injection), the problem is magnified.

 

Even more alarming is that these deposits can dislodge and damage other downstream components (turbochargers, catalytic converters, etc.). Manufacturers have added systems to capture these oil droplets and particulates, but no system is 100% effective. As a result, there are many disappointed early adopters with large repair bills. Even diesel engines haven’t been immune to these issues.

 

The reason these issues have slipped through to production is that they won’t show up in a 500,000 mile torture test. These types of issues will appear after years of short trips (preventing the engine from reaching operating temperature), bad batches of fuel, etc. As we approach the efficiency limits of the internal combustion engine, the engines themselves (and associated support systems) have become more complex. As with the transition from carburetors to electronic fuel injection, there will be some overlap between relatively bombproof port injected engines and the unproven, first-generation GDI engines.

Posted in Industry, News Blog
Tagged as andrew bell, ask an engineer, Direct Injection, Engineering, fault, gasoline direct injection, gdi, problem, Recall

 

So basically  the only real way we know of so far (As of this writing) in keeping an engine clean and working correctly is to do additional cleaning services at the oil change intervals AND do the oil changes way sooner than the maintenance schedule shows to do it. Every 7500 miles is way to long!

 

We do offer these additional services here at Westwood when we perform an oil change. We can install oil conditioner every oil change and at the 10,000 mile interval we can do the “works” which cleans the engine internally, cleans the fuel injectors and add the engine conditioner.

 

COST: Additional $24 every oil change for conditioner. and additional $69.95 plus tax. every third oil change (Every 10,000 miles). .

 

OPTION: Don’t clean it and spend hundreds and possibly thousands of dollars when it finally breaks. Some cars have been known to go only 15,000 to 20,000 miles before they have had to have major repair! Just ask the dealers.

 

Oh and one more thing. This has absolutely nothing to do with whether you use standard or synthetic oils. The problem is with the design
of the engine, not the type of oil you use.

 

Hugh