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Common Duramax 6.6L Diesel Engine Problems

Drive a 6.6L Duramax diesel? Then you might have to face the following common problems. If you do, we here at United Diesel Repair can help. We specialize in diesel engines of all shapes and sizes, and our technicians are experts in Duramax maintenance and repair. Over the years, we’ve found these common problems to be the biggest hassle for our customers who drive the 6.6L engine. 

Fuel Line/Starvation Problems

There are two keys issues with the Duramax 6.6L that we come across frequently, and they are air in the fuel lines and fuel starvation. The fuel filter’s housing design is the culprit. Because the Duramax engine doesn’t have a lift pump, the fuel filter’s housing can crack easily under the injection pump’s pressure.

Water Pump Problems

The most common problem with the water pump in the Duramax diesel 6.6L engine is total failure, and this spells serious trouble for you. We won’t candy-coat it, the water pump’s design is flawed. Consequently, you’ll likely need a new water pump after 80,000 to 100,000 miles of driving.

Overheating Engine

Naturally, if the water pump is failing your Duramax engine will overheat, but some customers still have overheating problems even if the water pump is fine. If your Duramax diesel truck is a 2005 or older, you may find the engine overheats quite a bit in the summer because the fan clutch fails.

Failing Injector

This problem is also common in older models, primarily 2001 to 2004 Duramax LB7 trucks. The injector failed prematurely in these years and model because of a design flaw. Newer Duramax diesel engines have an updated injector designed not to fail prematurely, but all injectors are contaminant-sensitive.

Glow Plug Problems

If you drive a 2006 Duramax LBZ or LLY, you might have problems with the diesel engine’s glow plug. This problem is well-known and most owners have already had it fixed. In this case, the glow plug module over-cycled the glow plugs, which, consequently, deformed and broke them.

Turbocharger Oil Contamination

Finally, because of the PCV design, many Duramax diesels end up with oil contamination in the turbocharger. The oil can degrade the intercooler boots because it coats the intercooler and its tubing. Oil is introduced into the turbocharger via the PCV, which wasn’t designed as well as it could’ve been.

There’s only one shop in Flowery Branch, GA, that you need to take your Duramax diesel to for preventative maintenance and repair and that shop is United Diesel Repair. We know all things Duramax, so call us today at 770-967-8333.

Photo by Groceris from Canva Pro
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