Suche
Mein Konto
No more LSPI
In a conversation with Liqui Moly development manager DAVID KAISER, we get to the bottom of the phenomenon of low speed pre-ignition and find out what can help affected engines.
No more LSPI
BY PHILIPP BEDNAR
Motor vehicle economy: Mr. Kaiser, what is meant by LSPI?
David Kaiser:The abbreviation LSPI stands for “low speed pre-ignition” and describes the premature ignition of the gasoline-air mixture in the combustion chamber before the ignition spark occurs – a knock. Unlike high-speed knock, LSPI occurs at low speeds under full load. For example, if you step on the gas just above idle in second gear.
Opel has openly addressed the LSPI problem on some engines. Are other brands also affected?
Yes, definitely. It's true that Opel addressed the issue aggressively at first, but other engines from other manufacturers are also affected. LSPI occurs primarily in high-compression gasoline direct injection engines with high turbocharging. It only affects gasoline engines.
How to detect LSPI?
Since it is not yet 100 percent clear how LSPI occurs, the diagnosis is also difficult. With a normal diagnostic tool it is difficult to identify the premature ignitions. As a driver, you may notice the engine running more unevenly. If you measure the cylinder pressure, you can see the phenomenon because there are dramatic pressure spikes that are literally equivalent to a detonation of the fuel-air mixture.
What are the causes of LSPI?
Although it has not yet been fully clarified, it is assumed that there are impurities and oil residues in the combustion chamber, which self-ignite due to the high temperatures and pressures in the combustion chamber and thus prematurely ignite the gasoline-air mixture. Poor fuel quality can also be a reason. We at Liqui Moly therefore have two approaches to dealing with the problem. On the one hand, with a special motor oil, the Liqui Moly Special Tex DX1, which meets the latest Opel and General Motors standard “Dexos 1 Generation 2” and prevents LSPI thanks to its special recipe. The second product is our fuel additive Pro-Line Direct Injection Cleaner. This contains the active ingredient polyetheramine (PEA), a highly effective cleaning chemical that also removes stubborn deposits on injectors, pistons and in the combustion chamber and thus prevents LSPI. The deposits that cause premature ignition are removed.
What damage can LSPI cause?
Significant damage. Especially since customers usually only notice something about it when it is too late. The consequences are broken connecting rods, damaged top lands on the pistons and complete engine damage. There is currently no 100 percent protection against LSPI, but with the right oil and our cleaning additive you can significantly reduce the risk. The first problems became known around 2010, and the problems have increased significantly since 2012 to 2014.