What causes low speed pre-ignition?

Have you ever been right in the middle of the most amazing story you’ve ever told and someone walks up and starts a new conversation right before your punchline?

Of course you have. We all have. And… it’s so frustrating!

That’s exactly what’s going on with GDI (gasoline direct injection) engines today. Engine oil is invading the combustion chamber and fuel deposits are interrupting the injectors’ fuel spray. These really annoying events are causing engine misfire.

What’s an engine misfire?

First, let me explain what the engine needs to NOT have a misfire. A near perfect balance of Fuel+Oxygen ignited with a Spark. If any of these are lacking, your engine will misfire.

GDI engine misfires are usually associated with engine oil getting into the combustion chamber, or fuel deposits restricting the injection system. (If you’re wondering if you have a GDI engine, if you’re driving a gasoline engine that’s 2010 and newer, chances are, it’s got a GDI engine.)

Low Speed Pre-Ignition LSPI

The official automotive term for this type of misfire is LSPI, or Low Speed Pre-Ignition. LSPI occurs when low speed, heavy engine load operation creates a high rpm environment inside the engine. When engine oil contaminates the combustion chamber, the engine misfires.

Tiny droplets of engine oil igniting with the fuel causes two separate explosion events within the combustion chamber. This creates an uncontrolled explosion (misfire) which can create enough force to damage pistons and connecting rods, causing catastrophic engine failure.

So unless engine oil is prevented from contaminating the combustion chamber, and unless fuel injection spray can operate without deposits on the injector tip, LSPI will occur.

How to Stop LSPI From Destroying Your Engine

Don’t let deposits and oil contamination stop the conversation happening in your engine! Maintain your engine. With regular use, BG EPR® and BG Platinum® 44K® go a long way in keeping these engines clean, while preventing problems like those associated with LSPI.

BG EPR®, Engine Performance Restoration® will keep the engine from allowing excess engine oil from getting into your combustion chamber. It is especially effective in maintaining cleanliness and the sealing function of low-tension piston rings. By reducing engine oil migration into the combustion chamber, you eliminate the possibility of the oil burning with the fuel and causing misfire.

BG Platinum® 44K® fuel treatment will keep the high pressure, precision-driven GDI fuel injectors clean and spraying fuel as designed. Clean injectors spray very tiny, well-dispersed fuel droplets. When fuel injectors get dirty, their fuel spray pattern is disrupted, causing misfire and engine damage.

With GDI engine technologies here to stay, it is more important than ever to maintain your engines to be as clean as possible.

By Michael Belluomo
Technical Service Manager
Mike has 35 years of experience in fuel and lube technologies. He manages all product-related inquires and assists with BGU and Distributor-specific training. He is a regular contributor of articles on product understanding and technical industry trends.

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