It will be your oil cooler at fault, causing the oil and coolant to mix. Our workshop has done 3 in the last 3 weeks. Also the VW T5 vans with the same engine have the same fault. Here is the technical bulletin.
Transaction No.: 2007699/4
Oil in coolant/coolant warning light on (5 cyl.)
Release date: 07-Sep-2007
The coolant warning light is on, although sufficient coolant is available.
The coolant in the reservoir is contaminated with oil, this falsifies the display value of the coolant level sender.
Internal leak on the oil cooler.
Optimised oil cooler from engine number:
BAC no longer in production
BLK no longer in production
If there is oil in the coolant, the oil cooler must be replaced.
Add G 052 188 A3 at a 1:1 ratio to remove the oil from the cooling system.
Clean the cooling system for about 10 minutes at operating temperature after the thermostat opens. Perform a test drive. Drain the coolant drain and flush the cooling system with water. If necessary, repeat the cleaning.
For a complete draining the cooling system must be opened on the heating transition point at the right front drive shaft/steering rack. For the draining of the engine take off the right screw on the water pump worm gear as this is the lowest point of the cooling system.
Perform a 40 km test drive and check whether the complaint is fixed.
Do not replace any further parts (such as cylinder head gasket or cylinder head ), as this does not cure the problem.
If it becomes necessary, only replace the coolant reservoir after the cleaning.
Service number /damage code/ manufacturer: 1740/ 050/ ...
17 40 19 70
Remove and install oil cooler
01 50 00 00
Guided fault finding / guided function
2) TU according to diagnosis protocol
19 01 29 99
Clean cooling system
19 38 17 99
Drain and fill up coolant
19 40 55 99
1) Use the specified time only for this TPL.
2) The necessary time for using the VAS tester is not included above, these times are assessed separately.