Tips for Keeping Your 6.6 DuraMax In Tip Top Shape

May 20th, 2024 by

Front view of the GMC Sierra 3500 HD Denali towing a trailerThe GMC Sierra Heavy Duty lineup of trucks features the tried-and-true 6.6-liter Duramax turbo-diesel, one of the most respected and appreciated motors on the market. Truck buyers all over the country will happily tell you how much they love their Duramax diesel truck and how it’s helped them. Whether you are towing for fun or as a profession, having a diesel engine like the 6.6-liter Duramax can help you succeed. 

Proper Maintenance Is Key

Like any engine, the Duramax must be properly maintained to help ensure its long, long life. There are loads of stories about Duramax Sierra trucks lasting hundreds of thousands of miles without any major issues. It’s easy to say this is because GMC is professional grade and stop right there, but it goes beyond the catchy slogan. The engineers at GMC take great pride in designing and building the 6.6-liter turbo-diesel to be something that can be relied on. 

An Overlooked Item To Replace

Something that is not checked often enough on both gas and diesel engines is the fuel filter. The recommendation here is to change it every 15,000 miles to ensure that your fuel pump isn’t working harder than necessary to filter out impurities from going into your engine and permanently damaging it. Every 7,500 miles, an oil and oil filter change should be done with a high-quality 15w-40 or 5w-40 diesel oil, depending on the climate that you live in. You shouldn’t wait any longer than 10,000 miles between oil change intervals. When changing your oil, you should also check on your engine air filter, which should be changed, if not every oil change, about every six oil changes. It should be changed sooner if you live in an area with lots of sand and dirt. 

2020 GMC Sierra 2500 HD Denali

The Cooling System

The cooling system is also an often forgotten but essential part of an engine. Coolant is a necessary element in keeping your engine from overheating. Check your coolant expansion tank every time you change your oil to be sure there is enough in the system and that it does not look dirty. It should be changed about every 3-5 years. The trick is never to let your coolant run low, or you can seriously damage your Duramax and incur a massive bill from a service shop to fix it. If you notice during oil changes that your coolant is at the minimum mark every time, then that means you have a leak somewhere or your water pump needs to be replaced. While this isn’t exactly a common problem on a brand-new truck, it is something to keep an eye on. 

Pay Attention To Your Serpentine Belt

A new serpentine belt should be fitted roughly every five years or sooner if you hear squeaking from the engine as you start your truck or drive away. Squeaking can signify premature wear and potential imminent failure. 

Side view of the GMC Sierra 3500 HD Denali towing a trailer

Engineered To Be Reliable

Plenty of owners swear by the 6.6-liter Duramax’s reliability and usability. It is a popular engine choice for professionals as it is engineered to last a very long time and withstand loads of stress over the course of ownership. The physical demands that owners put their Duramaxes through prove that it’s a great motor to tow and haul with. 

At Valley GMC, we pride ourselves on offering the best sales and service possible. With dozens of new and used vehicles available, our incredible sales team and finance department can help you find the best car for you and your family. And our fantastic service department will work hard to maintain your vehicle to the highest standards.

We look forward to serving you.