Turbocharger/Intercooler - Oil Leaks/Consumption
Date: April 1998Order No.: S-SI-MBNA-09/08
Supersedes:
Group: 09
SUBJECT:
ENGINE 606.962, TURBOCHARGED DIESEL ENGINE REPAIR INFORMATION
This bulletin covers important points regarding component repair and servicing of the intercooling and turbocharger Systems.
A. Intercooling system
^ Oil soaked intercooling hose connections
^ Intercooling hoses slide off
B. Turbocharger
^ Oil consumption
^ Flange sealing between turbocharger and exhaust manifold
^ Noise complaints
^ Testing and inspection criteria
A. Intercooling System
Numerous changes have been introduced since the start of series production, for example:
The attachment length on the piping has been increased in length from 22 to 30 mm (Figure 1).
Only the latest version is available as a spare part.
Addition of a groove for improved clamping and hose retention (Figure 2).
Hose clamps with integrated tension spring (Figure 3).
Tightening torque: 4 Nm.
Parts Information
Oil soaked Intercooling hose connections
Oil vapors originating from the oil separator form a coating of oil inside the intake port on the cylinder head and all the intercooling passages. This oil coating lubricates the valve head preventing wear and breakage. A small quantity of oil may collect in the intercooler. It is acceptable that oil may settle in small pockets in the creases of the intercooling hoses (the oil must not be swept away with the charge air stream).
If complaints are received, only seal the affected Intercooling hose connections. This is not justification for turbocharger replacement!
Please use Damage Code 50 306 04.
Procedure
Visually inspect the attachment area and connecting surfaces for scoring, especially the raised section adjacent to the groove on the pipe. Light scoring can be removed using fine emery cloth in a circular direction around the circumference of the pipe.
Prior to assembly, clean all mating surfaces (must be free from grease and lubricants). Use a suitable cleaning agent, e.g. part no. 001 986 28 71.
Install the latest version hose clamps with the integrated tension spring.
Intercooling hoses slide off
In case of repairs, please observe the following points.
Intercooler:
Measure the sealing bead height on the intercooler inlet and outlet.
Minimum height is 1.5 mm.
Remove any light scoring and/or scuffmarks using fine emery cloth in a circular direction around the circumference of the pipe.
Install intercooler and intercooler piping with the 30 mm attachment length (Figure 1) and grooved ends (Figure 2).
Inspect connecting points on plastic mounting sleeves
Inspect and verify the presence of the inner seat of the mounting sleeve.
Hose seats which are out of round or distorted must be replaced.
Installation note:
Prior to assembly, clean all mating surfaces (must be free from grease and lubricants). Use a suitable cleaning agent, e.g. part no. 001 986 28 71.
Install the latest version hose clamps with the integrated tension spring.
Please use Damage Code 50 307 38.
B. Turbocharger
Oil consumption
Upon inspection, the majority of returned turbochargers were found to be o.k. with respect to oil consumption. Oil found at the compressor inlet and consequently at the compressor outlet is an indication of oil venting out of the oil separator.
Please observe the following points before replacing the turbocharger.
Verify that the correct oil dipstick is installed in the engine.
Perform an oil consumption test. Refer to Workshop information System (WIS), group 18, AR 18.00-P-0025-01D.
Visually inspect the exhaust. If blue smoke is observed;
^ Inspect cylinder with light probe. Refer to SMS job number, AR 01 .00-P-0200 HA.
^ Inspect camshaft housing and first bearing cap. Refer to Diagnostic Directory, job number, AF05.20-U-3600AU.
Flange sealing between turbocharger and exhaust manifold
Small traces of exhaust do not require repair or resurfacing. There must be a leakproof seal between the turbocharger and exhaust manifold at normal operating temperatures. If noise complaints are received, remove turbocharger and exhaust manifold. Using a straight edge and feeler gauge measure both surfaces for distortion. In case of repair, use Damage Code 09302 04/19.
Maximum distortion: 0.08 mm.
Noise complaints
Before replacing the turbocharger, first inspect the components of the intercooling system and the front section of the exhaust system for any leaks. See damage code microfiche tables, 09.40 and 09.41.
Testing and inspection criteria
The turbocharger as a mechanical component can be removed and tested as follows:
Visually inspect the turbine and compressor wheels for damage.
Turbocharger vanes must not make contact with the housing.
Check for play in the turbine shaft bearing. The turbine and compressor wheels must move together simultaneously when pressed up or down. No noticeable play should be detected. The turbine shaft must turn without resistance.
In case of repair/replacement use Damage Code 09301 and the most applicable damage type. See Damage Code microfiche table 09.40.