In this article we’ll share some of the tips and methods for easier starting of the diesel car in winter that has worn out glow plugs. These are not permanent solutions, but will do in a pinch. Things like winter fuel additives, weird method with hot air gun and start fluid spray will be covered and explained.

List of content:

What are glow plugs?

A glow plug is an essential component in diesel engines, designed to aid in starting the engine, particularly in cold conditions. It works by preheating the air in the combustion chamber to ensure the diesel fuel ignites efficiently when compressed.

How Glow Plugs Work?

  1. Diesel Engine Basics: Diesel engines rely on compression to ignite fuel rather than spark plugs (used in gasoline engines). The air in the combustion chamber is compressed to high pressures, increasing its temperature to a point where injected diesel fuel ignites.
  2. Cold-Start Problem: In cold weather, the air temperature and the cylinder walls can be too low for reliable ignition. This is where glow plugs come in.
  3. Heating Element: A glow plug is a small, electrically heated element (similar to a filament) that sits inside or near the combustion chamber. When activated, it heats up to very high temperatures (up to 1000°C or more) within seconds, warming the air in the chamber.

Types of glow plugs

  • Metal Glow Plugs: Made of heat-resistant metal, these are the most common and durable.
  • Ceramic Glow Plugs: Higher performance and faster heating, they are often used in modern diesel engines for better efficiency.

Functions of Glow Plugs

  • Preheating: Before starting, glow plugs warm the combustion chamber for smoother ignition.
  • Post-Heating: In some modern engines, they stay on after the engine starts to reduce emissions and improve performance.
  • Support in Extreme Cold: Glow plugs are crucial in subzero temperatures, preventing misfires or difficult startups.

Common issues caused by bad glow plugs

  • Failure to Start: A malfunctioning glow plug can lead to hard starts or failure to start in cold weather.
  • Decreased Fuel Efficiency: Bad glow plugs can reduce engine efficiency and increase emissions.
  • Wear Over Time: Glow plugs naturally degrade and need periodic replacement, usually every 80,000–100,000 kilometers.

Tips for easier starting with worn glow plugs

Disclaimer: we are not sponsored by any of the products mentioned in this article

1. Using a start spray

A diesel start spray, often called starting fluid, is a chemical aerosol spray designed to assist in starting diesel engines, particularly in cold conditions or when the engine has difficulty starting due to other issues. It is typically composed of highly flammable substances, such as ether, combined with lubricants and anti-corrosion agents.

CAUTION

Excessive and improper use of starting fluid can cause severe damage, including:

  • Engine Knock or Detonation: The high combustibility of ether can cause abrupt and forceful ignitions, potentially damaging pistons, rods, or cylinder heads.
  • Glow Plug Damage: In engines with glow plugs, starting fluid can ignite prematurely, risking damage.

It’s intended only for emergency or occasional use.

How to use Mannol Motor Starter spray?

While the instructions for using the start sprays could be quite similar, we’re just going to explain how to use the one from Mannol. Take a look at your product packaging and read about differences in method of use.

  • Shake the spray can.
  • Spray the product directly into the air filter or intake duct for up to 2 seconds at distance of about 20 cm, and then start the engine immediately.
  • Do not spray on the spark plugs and parts of the heating system.

2. Using winter fuel additives

There are special fuel additives that are adjusted in chemical structure to aid in starting in low temperatures. When temperatures drop, diesel fuel forms wax crystals that can clog the filter and block the flow of fuel. The result? Noisy engines that struggle to start.

Such additives usually contain a diesel fuel anti-gel additive and cetane improver. Like a diesel anti-freeze for your engine, the anti-gel helps prevent the formation of wax crystals, while the cetane improver aids cold start performance even in extreme conditions.

How to use winter fuel additives?

They are used as all the other fuel additives, just by adding the additive directly to the fuel tank, the ratio of the fuel and the additive varies from manufacturer to the manufacturer, therefor please read the instructions on the product for proper usage.

3. Hot Air Gun

A genius method by the creator TequilaGarage, ran into it on Youtube and was blown away with his video.

The process is really simple:

  • Take something that produces hot air, a hair dryer or a hot air gun.
  • Find your intake manifold pipe and disconnect it from the air box
  • Turn on the heating device and put it in the intake manifold
  • Wait for 30s to a minute, connect the intake pipe and try to start the car
  • Repeat the process until the car starts

Why this works? Well, you’re pretty much doing the job that glow plugs are supposed to do, you are just heating up the air that is going to be used in combustion process, as simple as that.

The full process you can see in this video

Hopefully some of these tips will help you out in tricky situations and you can decide which ones you want to use depending how much time and which tools you posses.