Diesel Engine - Turbocharger Diagnostic Tips
NUMBER: 11-003-04GROUP: Exhaust
DATE: July 30, 2004
SUBJECT:
Turbocharger Diagnostic Tips
MODELS:
2002 - 2004 (VA) Sprinter
PARTS REQUIRED:
DISCUSSION:
Care must be taken when diagnosing turbochargers. Whistling-like sounds are not usually caused by the turbocharger itself. More common sources of whistling-like sounds can often be found at line connections. A leaky flange, an improperly positioned seal, a line connection at the turbocharger, or a line connection where there is an "offset" in the charge air system are possible sources of a whistle-like sound.
It is typical to notice a small amount of engine oil in the air inlet system. This comes from the crankcase ventilation and may weep out of hose connections that are not clamped properly. This does not mean that the turbocharger requires replacement.
As a mechanical component, the turbocharger has a relatively simple structure and, depending on the installation, can be checked either in the vehicle or after disassembly.
Before replacing a turbocharger, be sure to check the following:
CAUTION:
The engine must not be running (off) when performing these diagnostics.
1. The turbocharger compressor/turbine shaft should spin easily.
2. The compressor/turbine shaft must never scrape against the turbocharger housing.
3. Visually inspect all the blades of the compressor and turbine wheel for damage or scraping marks on the housing. Damage may have been caused by foreign particles. For example; if the air filter was improperly installed or an incorrect filter was installed, this would allow foreign particles to enter the turbocharger. Be sure the correct air filter is properly installed. Refer to the Parts Required table for correct part numbers.
4. Ensure that all of the air charge duct connections are sealed and properly clamped. This will insure that no air is allowed to enter without passing through the air filter.
5. Check the bearing clearance of the compressor/turbine shaft by deflecting upward or downward while rotating the compressor/turbine at the same time. When doing so, the compressor/turbine shaft must not scrape against the housing. Usually if there is excessive bearing clearance, there is compressor/turbine wheel damage.
Turbochargers with compressor/turbines damaged by foreign particles are not covered by warranty.
POLICY:
Information Only
Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.