BMW 125i M Sport Convertible Engine Rebuild Due To Oil Sludge Contamination
This client brought his BMW 125i M Sport Convertible in to GP Motor Works because the engine was overheating. Excessive overheating causes significant damage to the engine.
Our initial visual investigation of the oil cap showed evidence of oil and water mixture which is never a good sign. This invariably indicates the head gasket has blown. The head was removed and sent to engineering for refurbishment.
The story got worse when the tappet (valve) cover was removed (photos at the end). The inside surface of the tappet cover and the engine were completely covered with oil sludge and other contaminants. We have seen many cars with this problem at our workshop.
What Causes Oil Sludge?
Oil sludge is a thick slurry which is formed by oxidation as well as contamination of the oil. This slurry is carried around the engine and sticks to the various engine parts. If not removed quickly it tends to bake onto the surfaces.
There are many reasons why the engine oil turns to sludge:
- not following manufacturer’s oil change schedule
- mixing mineral based oils with synthetic oils
- topping up with the incorrect oil
- using a lower grade, inferior oil
- causing the oil to operate out of the specified heat range for extended periods
- not servicing your car as scheduled
- oil contamination
- not checking oil levels on a frequent basis
Water Leaks Found
Once the head was received the engine was rebuilt and new parts were added where necessary. This was followed by a coolant pressure test which showed radiator and heater pipe leaks. These were fixed.
Recommendations
We have written several articles about the importance of oil in your car’s engine (refer to list at the end of this article).
Suffice to say the oil can be likened to our blood. When our blood is “contaminated” it causes damage to the blood vessels which leads to blockages and clots and if not detected can be fatal.
From your car’s perspective, this happens when you don’t ensure your oil is changed on a regular basis. Unfortunately, either way, the cost to fix the problem is expensive!
Arrange an oil check and service and save yourself the cost of an engine rebuild!
Using Liqui Moly Products to Improve Performance by Removing Engine Sludge
