Photo by Tim Mossholder

Originally Posted On: https://wefixdieseltrucks.com/what-starting-problems-can-mean-for-a-diesel-engine/

 

Does your diesel truck have starting problems every time it’s cold outside? Or, does it have trouble starting no matter what the weather is like?

If so, we can help. Or rather, we’ll help you help yourself.

You see, there are a lot of different issues that might be causing your diesel engine problems. So, we’re going to show you how to check for these issues and diagnose what’s wrong with your engine.

We’ll even show you how you can solve some of these issues by yourself. Of course, if you can’t fix the problem yourself, we can help with that, too. (We are, after all, experienced diesel repair specialists.)

Still, before you bring your truck into the shop, try troubleshooting these diesel engine starting issues first.

Cold Weather Issues

There are many, many diesel engine starting problems that are caused by cold weather. Some of these can be fixed without professional help. But it’s easier to prevent them in the first place.

To start with, cold temperatures lower your battery output. This means there are fewer amps available for cranking your engine.

Secondly, the cold thickens the oil in your crankcase. Certain oils become so thick in winter that it hinders the cranking of your engine. Thus, oil that’s fine in warm weather, like 15W-40, should not be used when temperatures reach freezing or below.

Troubleshooting Cold Weather Starting Problems

If thickened oil is the problem, you’ll hear your engine cranking more slowly than usual when you attempt to start it. In this instance, pop open the hood and check the dipstick.

If the oil is clumpy instead of fluid, you need to change it out with a lighter oil. 10W-30 should be fine. Or, for extreme cold, you can try a CG-4 rated synthetic oil.

Furthermore, if you can get the truck into a warm garage, it may allow the oil to warm up and become liquified again.

Of course, the slow cranking could also indicate a battery problem. Check the battery connections and clear away any corrosion on the terminals.

Test the battery to make sure it’s in good health. If it isn’t, replace it.

Glow Plug Issues

On the other hand, your diesel truck may be equipped with glow plugs to prevent cold-weather starting problems. However, these glow plugs can burn out over time and cease to function properly.

Troubleshooting Glow Plug Issues

If your truck is having cold-weather starting problems when it never did before, that could be a sign that your glow plugs are wearing out. Other signs are rough idling and white smoke emanating from the exhaust pipe after startup.

You can test the glow plugs to make sure they’re working if you have a multimeter. Otherwise, you can take your truck in for a checkup. Then, simply replace the defunct glow plugs.

Fuel Delivery Issues

Perhaps the problem is a fuel delivery issue. This could be from a clogged fuel filter, incorrect injector timing, air bubbles in the fuel, or other causes. There are many parts involved with fuel delivery so there are a lot of things that can go wrong during the fuel’s journey to the engine.

Troubleshooting Fuel Delivery Issues

First, check your fuel filters. Clogged filters can cause a lot of fuel delivery issues. Thus, your primary filter should be changed approximately every 30,000 miles and the secondary every 20,000.

Next, use a scan tool to make sure the injector timing is correct. Your owner’s manual will help with this.

Lastly, check for air bubbles in the fuel. You can do this by installing a clear return hose on the injector pump and then cranking the engine. If you see air bubbles, you probably have one or more leaks in your fuel lines.

Fuel Injection Issues

Your diesel injector can get clogged up with varnish/gum deposits and all sorts of other gunk. A lubrication additive in the fuel could help to prevent this, though. Additionally, the pressure in your injector can diminish over time.

Troubleshooting Fuel Injection Issues

If you have a pop tester, you can test the opening pressure of your injector. It should be at 300 psi or above.

Otherwise, check the symptoms. If your injector is dirty, you’ll notice rough idling and a loss of power.

This can also cause white smoke to emanate from the exhaust pipe. On the other hand, if your injector is leaky, you’ll see black smoke in the exhaust. In any case, you should have your truck examined by a diesel repair professional if you’re experiencing injector problems.

Fuel Contamination

Unlike regular gasoline, diesel fuel provides ideal living conditions for certain microbes. Bacterial growth is more likely to happen in warm weather and especially if there’s water in your diesel fuel tank.

These colonies will coat the inside of the tank with a black or green slime that smells like rotten eggs. This is seriously bad news for your fuel system, which can get clogged up by these contaminants.

Troubleshooting Fuel Contamination Issues

If you see these signs in your fuel tank, you’ll have to thoroughly clean it out and disinfect it.

First, empty the fuel tank completely. Then, clean it out with a biocide that’s intended for this purpose. Lastly, refill the tank with fuel, plus a little bit more of the biocide.

Does Your Diesel Truck Have Starting Problems?

If you’re experiencing any of the starting problems on this list, follow the steps above. Or, if you’re still having trouble, let us help.

We have the expert knowledge and experience to solve any issue you’re having with your diesel truck. Call us at (916) 652-9457 or send us any questions you have through our contact page.