blog post

Diesel Fuel Filter Replacement at Jamestown | Independent Auto and Diesel Repair

Diesel Fuel Filter Replacement: Frequently Asked Questions

You may have heard that diesel engines need more maintenance than gas engines – and that is true, mostly because of the diesel fuel. Diesel is not refined as much as gas, so it’s inherently dirtier. Most diesel vehicles have two fuel filters, and you need to change them every 10,000 to 15,000 miles as opposed to a gas fuel filter, which can go for 100,000 miles or better. Independent Auto and Diesel Repair in Jamestown, TN can change the fuel filters on your diesel vehicle.

Diesel Fuel Filter FAQ

Our techs have answered some of the questions we frequently hear from our customers.

Does my diesel vehicle have two fuel filters?

Most diesel vehicles have two fuel filters: a Pre-filter, which is usually located between the fuel tank and the fuel pump. You’ll most likely find the pre-filter on the frame rail under the vehicle. The second diesel fuel filter is usually in the engine bay. Its job is to further clean the fuel of any contaminants. When you come into Independent Auto and Diesel Repair in Jamestown, TN, for diesel filter replacement, we’ll replace both diesel fuel filters.

How much fuel will I lose when you change the diesel fuel filters?

Not much. You will lose the fuel in the filter, filter housing and fuel line.

Another mechanic changed my diesel fuel filter some time ago, and it’s leaked ever since. Why?

The most common cause of leaks from a fuel filter is because the auto technician did not install the O-ring properly. If it is not seated against the ridge all the way around, it will leak. The diesel fuel filter must be removed and the O-ring replaced.

Another reason is that the mechanic may not have torqued the cap properly. If it is under-torqued or over-torqued, it will most likely leak.

What happens if I don’t change the fuel filter?

If you don’t replace the fuel filters, they can get clogged and cause pressure on the filter. Once that happens, the pressure will break the filter, which is usually paper or cloth, and those particles will enter the engine.

Additionally, the restricted flow of fuel will cause the engine to run poorly and cause a hard or no-start condition.

Finally, the debris could damage additional components, including the fuel injectors.

Can I bring my own fuel filters for you to install?

No, as we cannot provide a warranty if you bring your own parts.

Why do I need two fuel filters?

The pre-filter, or primary diesel fuel filter, removes most of the water and contaminants in the fuel. It protects the transfer pump, if there is one. It also protects the secondary filter, which is usually located in line after the transfer pump. The secondary fuel filter also removes the fine particles that get past the primary fuel filter. While they are small, they are still large enough to cause the injectors to malfunction.

Should I use additives in my diesel fuel?

Some additives contain alcohol, which degrades diesel fuel. Unless your vehicle’s manufacturer recommends an additive, you shouldn’t use them. If you feel you need them, you can also ask your diesel specialist which additives you need. For example, if it gets cold enough, the wax component in diesel fuel could solidify and clog the diesel fuel filter and lines. While this usually happens with farm diesel and not road diesel, you should ask your diesel specialist which is the best additive to use.

Contact Independent Auto and Diesel Repair

When it’s time for diesel vehicle maintenance, including changing the fuel filters, contact Independent Auto and Diesel Repair at (931) 863-2888 for an appointment. We are conveniently located at 4859 S. York HwyJamestown, TN 38556.