Turbocharger Failure Diagnostic Checklist

Your turbocharger not only helps your engine have more power, but it also helps with efficiency and emissions. When it fails, though, you can be left with more than just an inconvenience. Many systems in your engine can be affected by a damaged turbo, so it's important you identify and fix the correct issue to prevent any major failures. To help catch problems before they become a failure, check out our blog post, Signs You Should Have Your Turbocharger Serviced. The following list provides the most common symptoms related to turbocharger failure and possible causes. Before replacing your turbocharger take a look to see what might be giving you trouble!

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Engine running hot

If your engine is running hot, it may be because your turbo is overheating. Below are some things to check that could lead to this turbo problem:

Dirty air cleaner: Clean or replace element according to manufacturer’s recommendations.
Restricted compressor intake duct: Remove restriction or replace damaged parts as required.
Restricted air duct from compressor to intake manifold: Replace seals, gaskets or tighten fasteners as required.
Restricted intake manifold: Refer to engine manufacturer’s manual and remove restriction.
Air leak in feed from compressor to intake manifold: Replace seals, gaskets or tighten fasteners as required.
Air leak between intake manifold and engine: Refer to engine manufacturer’s manual and remove obstruction.
Restricted exhaust system: Remove restriction or replace damaged parts as required.
Failed diaphragm: Replace using correct actuator service kit.
Seized valve: Free valve/replace complete turbine housing sub-assembly.
Leaking hose: Replace hose and clips.
Wastegate mechanism set incorrectly: Get correct setting details.

Poor Transient Response

Another symptom that something could be wrong with your turbocharger is poor transient response, or difficulty changing between stages. Some things that might be causing this include:

Dirty Air Cleaner: You might be able to clean this, or you could replace it. Refer to your manufacturer instructions for more information.
Restricted compressor intake duct: Remove the restriction. Check for any damage and replace the necessary parts.
Restricted air duct from compressor to intake manifold: Find the cause of the block and remove it. Replace parts as needed.
Restricted intake manifold: Remove the restriction from the manifold and refer to the manual for further instructions.
Air leak in feed from compressor to intake manifold: This might require replaced seals or gaskets.
Exhaust manifold cracked, gaskets blown or missing: Refer to engine manufacturer’s manual and replace gaskets or damaged parts as required
Gas leak at turbine inlet/exhaust manifold joint: Replace gasket or tighten fasteners as required.
Gas leak in ducting after turbine outlet: Refer to engine manufacturer’s manual and repair leak.
Fuel injection pump or fuel injectors incorrectly set: Refer to engine manufacturer’s manual and replace or adjust faulty components as required.
Seized valve: Try to free the valve. It might require a replacement of the turbine housing sub-assembly
Wastegate mechanism set incorrectly: Reset to proper setting details.

Smoke

Smoke is never a good sign, especially when it could point to an issue with your turbo. Be sure to check out the following:

Dirty Air Cleaner: Clean or replace as needed.
Restricted compressor intake duct: Clear the restriction and complete any necessary repairs.
Air leak in feed from compressor to intake manifold: Replace the affected seals or gaskets, or tighten the fasteners.
Air leak between intake manifold and engine: Check out your engine manufacturer’s manual for more information.
Exhaust manifold cracked, gaskets blown or missing: Refer to engine manufacturer’s manual and replace gaskets or damaged parts as required
Gas leak at turbine inlet/exhaust manifold joint: Check for cause of leak and replace or tighten as needed.
Fuel injection pump or fuel injectors incorrectly set: Adjust or replace the components following proper guidelines from your manual.
Wastegate mechanism set incorrectly: Contact agent to get the right settings.

Engine Lacks Power

Have you noticed a decrease in your engine power recently? If your turbocharger isn't working properly, it's likely you'll have this symptom. Watch out for the following:

Dirty Air Cleaner: The element should be cleaned or replaced
Restricted air duct from compressor to intake manifold: Replace seals, gaskets or tighten fasteners as needed to fix the restriction.
Restricted intake manifold: Checking the engine manufacturer’s manual, remove the restriction.
Air leak in feed from compressor to intake manifold: Replace seals, gaskets or tighten fasteners as required.
Air leak between intake manifold and engine: Troubleshoot the source of the leak and replace the necessary parts.
Foreign object in exhaust manifold (from engine): Locate the object and carefully remove. Check your manual for more detailed instructions.
Restricted exhaust system: Remove the restriction or replace the damaged parts if required.
Exhaust manifold cracked, gaskets blown or missing: Replace the parts that were damaged.
Gas leak at turbine inlet/exhaust manifold joint: Depending on the location of the leak, replace the gasket or tighten the fasteners to address the problem.
Fuel injection pump or fuel injectors incorrectly set: Broken or malfunctioning components should be adjusted or replaced.
Engine valve timing incorrect: Refer to engine manufacturer’s manual for correct settings and adjust as required.
Worn engine piston rings or liners: Refer to engine manufacturer’s manual.
Burnt valves and/or pistons: Refer to engine manufacturer’s manual and repair as required.
Excessive dirt build-up on impeller and/or diffuser vanes: Clean in accordance with the appropriate repair manual.
Turbocharger damaged: Find and correct cause of failure, repair or replace turbocharger as necessary.
Wastegate mechanism set incorrectly: Make sure you have the proper setting details.

Black Exhaust Smoke

The color of your exhaust smoke says a lot about what's wrong in your engine. Here are some reasons your turbo might be causing black smoke:

Dirty Air Cleaner: The element should be cleaned or replaced.
Restricted compressor intake duct: Remove restriction and/or replace any damaged parts.
Restricted air duct from compressor to intake manifold: Replace the affected seals and gaskets, or tighten the fasteners as required.
Restricted intake manifold: Checking your engine manufacturer’s manual, remove obstruction.
Air leak in feed from compressor to intake manifold: This may require you to replace seals and gaskets, or to tighten your fasteners.
Air leak between intake manifold and engine: Refer to engine manufacturer’s manual and remove obstruction.
Foreign object in exhaust manifold (from engine): Clear the block following instructions from your manual.
Restricted exhaust system: Remove restriction or replace damaged parts as required.
Exhaust manifold cracked, gaskets blown or missing: Replace any damaged parts.
Gas leak at turbine inlet/exhaust manifold joint: Replace gasket or tighten fasteners as required
Fuel injection pump or fuel injectors incorrectly set: Adjust the components, or replace them if necessary.
Engine valve timing incorrect: Your manual should have the recommended settings. Adjust accordingly.
Worn engine piston rings or liners: Replace as necessary.
Burnt valves and/or pistons: Repair or replace the affected parts.
Excessive dirt build-up on impeller and/or diffuser vanes: Clean in accordance with the appropriate repair manual.
Turbocharger damaged: Find and correct cause of failure. You may need to repair or replace turbocharger, depending on the extent of damage.

Blue Exhaust Smoke

Similarly, a faulty turbo could also lead to blue smoke. Here are some reasons why:

Dirty Air Cleaner: Clean if possible, otherwise replace. As always, follow the manufacturer's recommendations.
Restricted compressor intake duct: Clearing the obstruction might help, but you also might need to replace the parts.
Air leak in feed from compressor to intake manifold: Replace the damaged parts, or tighten as you can, following manufacturer's recommendations.
Air leak between intake manifold from engine: Identify leak and tighten according to your manual's instructions.
Foreign object in exhaust manifold (from engine): Following proper procedures, carefully remove the foreign object.
Restricted turbocharger oil drain line: Depending on the extent of the damage, you might have to replace all affected parts, or you might be able to simply clear the block.
Restricted engine crankcase breather: Make sure you're referring to the proper manual for instruction on clearing the restriction.
Turbocharger bearing housing sludged or coked: This could require a complete turbo overhaul or replacement, but start by changing the oil and filter.
Worn engine piston rings or liners: Check out your manufacturer's manual.
Burnt valves and/or pistons: Repair as necessary, following instructions from your manual.
Excessive dirt build-up on impeller and/or diffuser vanes: Use your repair manual to help figure out the proper cleaning procedure.
Turbocharger damaged: Find and correct cause of failure, repair or replace turbocharger as necessary.

High Oil Consumption

A lot of things could cause high oil consumption, and a problem with your turbocharger is one of them. Here are some issues you could check:

Dirty Air Cleaner: Clean or replace element according to manufacturer’s recommendations.
Restricted compressor intake duct: Remove restriction or replace damaged parts, depending on the damage.
Air leak in feed from compressor to intake manifold: This may require you to replace the seals and gaskets or tighten fasteners.
Air leak between intake manifold and engine: Refer to engine manufacturer’s manual and replace gaskets or tighten fasteners as required.
Foreign object in exhaust manifold (from engine): Refer to engine manufacturer’s manual and remove obstruction.
Restricted turbocharger oil drain line: Depending on the extent of the block, you can either clear the restriction or replace the parts.
Restricted engine crankcase breather: The restrictions should be cleared according to proper procedures from your engine manufacturer's manual.
Turbocharger bearing housing sludged or coked: You'll need to change both the oil and the filter to help correct this. You might also have to overhaul or replace turbocharger to get this functioning normally again.
Worn engine piston rings or liners: Your engine manual should have the proper procedure for correcting this.
Burnt valves and/or pistons: These parts may need to be repaired or replaced. Refer to your manual for more information.
Excessive dirt build-up on impeller and/or diffuser vanes: Clean the build-up to help restore proper function. Check for any additional signs of damage.
Turbocharger damaged: Identify what caused the damage to your turbo. Repair or replace all affected parts.

Noisy Turbocharger

Is there a strange sound coming from your turbo? You might want to get that checked right away. Below are some reasons why your turbocharger could be making noises.

Restricted compressor intake duct: Remove restriction or replace damaged parts as required.
Restricted air duct from compressor to intake manifold: Replace seals, gaskets or tighten fasteners as required.
Restricted intake manifold: Check the manifold for cause of restriction and remove if possible, paying attention to your operating manual.
Air leak in feed from air cleaner to compressor: Replace seals, gaskets or tighten fasteners as required.
Air leak in feed from compressor to intake manifold: Check for proper sealing and tighten or replace as necessary.
Air leak between intake manifold and engine: Refer to engine manufacturer’s manual and replace gaskets or tighten fasteners as required.
Foreign objects: Carefully remove the obstruction and check for signs of damage.
Exhaust manifold cracked, gaskets blown or missing: Check for signs of damage and replace or repair according to your manufacturer's manual.
Gas leak at turbine inlet/exhaust manifold joint: Replace or tighten to help this issue.
Excessive dirt build-up on impeller and/or diffuser vanes: Clear the buildup to allow for proper function.
Turbocharger damaged: Locate the damage. This could result in the need for a new turbo.
Failed diaphragm: Replace using correct actuator service kit.
Leaking hose: You'll probably need to replace these parts.
Wastegate mechanism set incorrectly : Contact nearest distributor for correct setting data.

Cyclic Sound from Turbocharger

If you're hearing a more cyclic sound coming from your turbo, you might have a similar issue. Some causes might include:

Restricted compressor intake duct: Clearing the block or replacing damaged parts should help with this.
Excessive dirt build-up on impeller and/or diffuser vanes: Ensure that components are properly cleaned.

Oil Leak from Compressor Seal

A damaged turbocharger could also lead to an oil leak from your compressor seal. If you think that's the cause, you should take a look at some of the below issues:

Dirty Air Cleaner: Clean or replace element according to manufacturer’s recommendations.
Restricted air duct from compressor to intake manifold: Replace seals, gaskets or tighten fasteners as required.
Restricted exhaust system: Find and remove what's causing the block or replace the affected parts.
Exhaust manifold cracked, gaskets blown or missing: Depending on your engine model, replace the necessary parts. Look at your manual for additional instructions.
Restricted turbocharger oil drain line: You might be able to fix this by simply removing the restriction, but it also might require some parts to be replaced.
Restricted engine crankcase breather: Look for the restriction and clear if possible. Refer to your operating manual for specific instructions.
Turbocharger bearing housing sludged or coked: Change engine oil and oil filter, overhaul or replace turbocharger as required.
Worn engine piston rings or liners: Check out your engine manual.
Burnt valves and/or pistons: Your manufacturer's manual should have the proper information for replacing these.
Excessive dirt build-up on impeller and/or diffuser vanes: Clean in accordance with the appropriate repair manual.
Turbocharger damaged: Look for signs of damage on your turbo and fix if possible. Otherwise, you may need to replace it.

Oil Leak from Turbine Seal

There could also be a leak from the turbine seal related to turbo damage. Again, make sure you are thorough in your inspection to find the actual cause of the issue:

Restricted turbocharger oil drain line: You might be able to clear the restriction, but it might also require parts to be replaced.
Restricted engine crankcase breather: Clear out the restriction, but be sure to refer to you owners manual.
Turbocharger bearing housing sludged or coked: Start by changing the oil, but it might lead to a full turbo replacement.
Worn engine piston rings or liners: Take a look at your manual for proper identification of issues.
Burnt valves and/or pistons: The manufacturer's instructions can help you fix/replace these.
Excessive dirt build-up on impeller and/or diffuser vanes: Be sure to check your manual for proper cleaning instructions
Turbocharger damaged: If your turbocharger itself is physical damaged, make sure you identify and fix the issue.

Source IPD

Whatever is wrong with your turbo, it's something you'll want to address right away. We have a large selection of turbochargers to help you fix your turbo failure.

If you're not sure where to start, or need help verifying that a turbo will work on your engine, be sure to give one of our certified techs a call at 844-215-3406. Or, you can request a quote online. We're here to help with all your diesel engine needs!

Originally posted October 29, 2015, Updated July 29, 2019