Diesel Diagnosis: Common Problems With Diesel VGT Turbos & Actuators

You're having trouble with your diesel engine, and all signs seem to point to your VGT. 

But is that really what's failing?


Diesel VGT Turbo

Sometimes it's not as simple as you might think. It might actually be the actuator that's giving you trouble, depending on your application and the type of failure. 

So, before you spend a bunch of money on a new turbo, make sure you're correctly diagnosing the problem. 

Want to know how to tell if your actuator is the culprit? That's what we're taking you through in this post.

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Is it Your Actuator or Your VGT?

You're probably wondering, is it my actuator that's bad? Or is it my VGT? Could it be both? Here's some ways you can tell what's going on:


Removing the Actuator

One of the easiest ways to determine what's actually failing is to pull the actuator off. 

You might be getting codes that seem to indicate an issue with the actuator, but you still can't tell if it's a problem with the actuator or the turbo. 

So, we take off the actuator and take hold of the sector gear to move it from stop to stop. If it doesn't make a full travel, it's an issue with your turbo that's causing an actuator failure. 


What Indicates an Actuator Failure?

If you do that test, though, and everything moves easily when you move the sector gear, you're probably not looking at a turbo failure. It's more likely an issue with the actuator itself.

That's why removing the actuator is a good place to start. If you've got a turbo that moves normally, then it's probably an issue with the actuator, if not, you're likely going to want to replace the turbo, and possibly the actuator as well.


Other VGT Turbo Problems

If it is your turbo that has failed, you're going to want to figure out what's going on in the engine. There are several things that can lead to turbo failure, including:


1. Excessive Oil Consumption

Your engine might start consuming more oil than usual, possibly from a failed bearing, hot shutdowns, or extended drain intervals with incorrect or contaminated oil. 

It's also possible that you have a blocked crankcase filter that is pushing oil into the turbo. 

These are outside issues causing the turbo to fail, so they will need to be addressed, otherwise you'll keep having turbo failure.


2. Mechanical Faults

VGT turbos are complex components, and there are a lot of possible points of mechanical failure. If your turbo isn't shifting from a big turbo to a small turbo, you might be looking at a mechanical failure.


3. Electrical Faults

Many VGTs have electronic actuators. You might experience an electronic failure on these actuators.


What to Do If Your Having VGT Trouble

If you're experiencing turbo failure, you'll first want to figure out what's causing it: the turbo, the actuator, or both. 

Then, find out if it's another engine failure leading to your problems, so you can help prevent future failures from the same issue. 

If you need to replace your VGT or components, give us a call! Our ASE Certified Technicians can help you diagnose your diesel engine problems and make sure you get the right parts!

We have a huge inventory of diesel engine parts, so we'll make sure you're getting the components that will work with your engine. And we'll get them to you fast!

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