A Guide to Overhaul Duramax LB7 Injectors
Dec 2015 03

The Duramax engine is one of the finest ever to have been made for pickup trucks. But even the best can have a few faults. The original Duramax engine that rolled out back in 2001 and every variant that rolled out in the subsequent three years have a serious flaw. The fuel injectors are not among the sturdiest. The injectors have a substantial chance of failing, much before a hundred thousand miles. Should the LB7 injectors fail, they can leak substantial amount of fuel and dump it into the engine. This can happen when you are driving but also when your truck is idle. If the excess fuel leaked doesn’t get burned, then it can affect the oiling system and the engine will start to get filled with diesel. That is definitely not something you want!

While GM has offered an extended warranty to cover up to two hundred thousand miles, the injectors failing can be a bummer! LB7 injectors are pricey and they cannot be replaced unless one is very well trained. The injectors are so hard to reach that most people wouldn’t even be able to get to them, much less replace them.

When should you replace Duramax LB7 Injectors?

You must be observant of signs that your LB7 injectors have failed or have worn out. You may notice white smoke. Be careful because white smoke can also be a symptom of coolant loss or oil seeping into the radiator. But usually, white smoke is considered to be a cause of LB7 injectors’ failure in Duramax engines. Get your truck to a technician and one can test the balance rates of the injectors to know for sure if they must be replaced.

How to overhaul or replace Duramax LB7 Injectors!

First, the intake has to be removed. Then one must remove the fuel filter along with the housing and lines. One would then get access to the valve cover. The fuel injection control module has to be removed. It is typically mounted on the valve cover at the passenger side. There are several electrical and rubber connections that must be removed. Then you would get to the injector line. Take out the lower and upper valve covers and you would have access to the injectors.

The next steps involve removing the electrical connections, taking out the injector return line and then removing the injectors. You may need an injector puller for the job. Once the injectors in need of replacement are removed, new ones can be installed.

Leave a Comment