How to fix a Diesel that’s hard to Start Cold?

If your diesel is hard to start in cold weather, it usually gets worse as engine deposits build up over time. Types of operation such as excessive idling, short run times, light work and city driving all contribute to deposit formation, which can result in poor cold starts. None of these operating conditions allow efficient diesel combustion. Poor maintenance and general age will also contribute to deposit build-up.

Have you noticed your vehicle taking longer and longer to start in cold weather? Is it winding over and over and won’t start at all? When it finally turns over, is it blowing white diesel smoke out the exhaust and running rough until it’s warm? White diesel smoke at start-up is an obvious sign that things aren’t quite right — and if left untreated, it can become a much bigger problem.

Short answer: a diesel that’s hard to start cold is usually suffering from carbon, cylinder glaze or worn injectors. FTC Decarbonizer burns off these deposits and helps the fuel ignite faster — no major repairs needed.

Why Won’t My Vehicle Start in Cold Weather?

There can be many reasons for a vehicle not starting in cold weather. Some are as simple as a weak battery that needs replacing. Other contributing factors are a bit more complex, but can be easily fixed or avoided:

• Worn injectors not atomising correctly
• Excess carbon around glow plugs or spark plugs
• Old petrol or diesel not combusting correctly

Other, more serious issues can be compression-related:

• Engine oil sludge or stuck rings
• Excessive carbon build-up
• Increased cranking resistance

How Does FTC Decarbonizer Fix a Diesel That’s Hard to Start Cold?

FTC Decarbonizer acts as a combustion catalyst to help fuel burn FASTER and CLEANER. At start-up, the active component in FTC Decarbonizer ignites before the fuel, which in turn catalyses the fuel burn — resulting in faster cold starts. (For the full picture, see our guide on how FTC Decarbonizer works.)

Typically, deposits build up in several critical regions:

• Injector tips. This prevents optimum fuel spray atomisation, and distorts the spray pattern.
• Cylinder glaze. A fine build-up that fills the cylinder cross-hatching with carbon, making the bore glassy smooth, reducing cylinder compression and increasing blow-by. Good compression is essential for cold starts.
• Piston ring deposits. These also reduce crucial cylinder compression.
• Combustion and exhaust deposits. Carbon build-up in combustion spaces, especially on piston crowns, interferes with efficient mixing of the fuel spray and air. Exhaust deposits reduce the engine’s ability to breathe efficiently.
• Sludge and gummy piston rings. Apart from increasing internal drag — which adversely affects cold cranking and efficient lubrication — loss of compression can be quite severe.

Rather than carrying out expensive mechanical work to remove, clean and replace affected parts (or effectively overhaul the engine and fuel system), all of the above deposit types can be removed by safe chemical means, with minimal downtime. In fact, much of the clean-up occurs during normal driving. Many of these same deposits also cause engine blow-by, so the fix often overlaps.

The products below are well proven and recommended:

• FTC Decarbonizer. A combustion catalyst that ignites fuel more easily during cold starts and burns off carbon at lower temperatures than otherwise possible — clearing cylinder glaze, combustion, exhaust and even turbocharger deposits.
• Cleanpower Fuel Treatment. Fuel system detergents that restore cleanliness to pumps, lines and injectors, correcting distorted spray patterns for optimal fuel misting.
• Flushing Oil Concentrate. Detergent-based (not solvent-based) cleaning for heavy deposits — removes stubborn sludge and hard carbon to restore full compression and clean lubrication. See our guide on using Flushing Oil Concentrate.
• AW10 Antiwear. Added to clean engine oil, it reduces frictional drag throughout the engine, lowering the battery’s cold-cranking demand.

For more information on a diesel that’s hard to start, give the team at Cost Effective Maintenance a call on +61 7 3376 6188.

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