Holset Wastegate Failure Diagnosis

A quick and easy guide to identifying the causes of Holset Wastegate Turbocharger failures

From a Holset pocket pamphlet - Part Number 3580799

Introduction to Holset Wastegate Turbochargers

   Engine emission legislation has forced manufacturers to improve their efficiencies, particularly at low speeds where low air: fuel ratios cause high smoke levels.
   The Holset integral Wastegate turbocharger is a cost effective solution to this problem and for a small increase in complexity, a simple variable flow turbine housing has been achieved.

The Importance of Correct Settings
    The Wastegate turbocharger is a technical piece of equipment requiring accurate setting by the Original Equipment Manufacturer (OEM). Contact your local Holset dealer for details of which pre-set kit you should use to overhaul your turbocharger. It is very important to adhere to the settings of the kit when servicing your turbocharger, as failure to do so could result in turbocharger or engine damage.

Effects of Incorrect Settings
Possible consequences if the actuator is set to give less boost than is required.

Possible consequences if the actuator is set to give more boost than is required

Wastegate Check List Guidelines

Holset turbochargers are designed to last the lifetime of the engine, and with the minimum amount of maintenance i.e. regular oil and filter changes should be a trouble free engine component. Should you encounter a problem with your Wastegate turbocharger, it is advisable to check the following:

Leaking Actuator

  • Too much boost
  • Turbo overspeed
  • Engine overheating
  • Excess noise

Seized Wastegate Valve (Open)

  • Low boost
  • Poor fuel consumption
  • Excessive smoke

Never attempt to rotate the end adjuster as it will seriously affect the performance of the engine

Seized Wastegate Valve (Closed)

  • Too much boost
  • Turbo overspeed
  • Engine overheating

Never attempt to rotate the end adjuster as it will seriously affect the performance of the engine

Damaged or Cracked Valve Seat

  • Exhaust gas leakage

 

Fault Finding Chart
Note: R = Refer to engine manufacturer's manual
 Symptom#
1
2
3
4
5
6
7
8
9
10
11
Dirty air cleaner
Clean or replace element		 * * * * * * *     *  
Restricted compressor intake duct
Remove restriction or replace damaged parts as required 		* * *   * * * * * *  
Restricted air duct from compressor to intake manifold
Remove restriction or replace damaged parts as required 		* *   * *     *      
Restricted intake manifold
R - and remove restriction 		* *   * *     *      
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
Replace seals, gaskets or tighten fasteners as required 		* * * * * * * *      
Air leak between intake manifold and engine
R - and replace gaskets or tighten fasteners as required 		*   * * * * * *      
Foreign object in exhaust manifold from engine)
R - and remove obstruction 		      * * * * *   *  
Restricted exhaust system
Remove restriction or replace damaged parts as required 		*     * *         *  
Exhaust manifold cracked, gaskets blown or missing . .
R - 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
R - and repair leak 		  *           *      
Restricted turbocharger oil drain line
Remove restriction or replace damaged parts as required 		          * *     * *
Restricted engine crankcase breather
R - clear restriction 		          * *     * *
Turbocharger bearing housing sludged or coked
Change engine oil an(foil filter, overhaul or replace turbocharger as required 		          * *     * *
Fuel injection pump or fuel Injectors incorrectly set
R - and replace or adjust faulty components as required 		  * * * *            
Engine valve timing Incorrect
R - for correct settings and adjust as required 		      * *            
Worn engine piston rings or liners
R - and repair as required 		      * * * *     * *
Burnt valves and/or pistons
R - and repair as required 		      * * * *     * *
Excessive dirt build up on compressor wheel and/or diffuser vanes
Clean in accordance with details in the appropriate Holset publication 		      * * * * * * * *
Turbocharger damaged
Find and correct cause of failure, repair or replace turbocharger as necessary 		      * * * * *   * *
Failed diaphragm
Replace using correct actuator Service Kit 		*                    
Seized valve
Free valve/replace complete turbine housing subassembly 		* *           *      
Leaking hose Replace hose and clips *             *      
Wastegate mechanism set incorrectly Contact approved agent for correct setting details * * * *       *      

 

Symptom Key
# symptom
1 Engine Running Hot
2 Poor Transient Response
3 Smoke
4 Engine Lacks Power
5 Black Exhaust Smoke
6 Blue Exhaust Smoke
7 High Oil Consumption
8 Turbocharger Noisy
9 Cyclic Sound From the Turbocharger
10 Oil Leak from Compressor Seal
11 Oil Leak from Turbine Seal

The Holset web site has much more information, diagnostics charts, pdf service manual, etc.

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Last Update: March 27, 2000