The primary cause of these problems is that fuel and added detergents are not hitting the back of the intake valves.
Something as simple as checking the DTCs can go off the rails when the code isn’t translated properly by your scan tool.
This engine is unique due to the high-pressure fuel pumps driven by the crankshaft using a chain that turns the oil pump.
While understanding the symptoms of a failure are key to diagnosing the failure itself, replacing an expensive component based upon a symptom rather than a set of factual data is a very risky and expensive proposition. So, in the world of advanced diagnostics, it’s important to begin dodging the Silver Bullet solution as a diagnostic tool.
If your primary workflow consists of pre-2008 models, terms like “Gasoline Direct Fuel Injection (GDI), Homogenous Charge Compression Ignition (HCCI), Variable Compression Ratio (VCR) and Spark-Controlled Compression Ignition (SpCCI)” might sound like engine technologies lurking somewhere in the distant future. But, given that many import repair shops are just beginning to see these engines for advanced driveability diagnostics, your “distant future” might suddenly become your “here and now” when these futuristic engines show up in your service bays.
Remember the old carnival game where a dealer hides a pea under one of a half-dozen walnut shells? After the dealer artfully shuffles the six shells, you’re supposed to pick the shell with the pea hidden under it. Good luck with that. As veteran diagnostic technicians know, diagnosing a no-code intermittent stalling complaint can be like playing the old carnival shell game. We know it’s one of maybe six sensors, but why can’t we find the diagnostic trouble code (DTC) that tells us where to find the pea?
Replacing a head gasket is a significant investment for the customer. It also represents significant risk for a shop if the replacement gasket fails. To do the job right, you have to ask why the gasket failed in the first place and what it will take to prevent it from happening again.
One of the ways automakers squeeze more horsepower and torque from an engine is by adding variable valve timing (VVT) to the valvetrain. A conventional camshaft has fixed valve lift, duration and timing; so, the grind is always a compromise between fuel economy, performance and emissions. But with VVT, duration, valve overlap and timing can be changed on the go to optimize engine performance at different RPM, loads and operating conditions.