Replacing a charge air cooler after turbocharger damage
Do I also have to replace the charge air cooler after a turbocharger damage?
Faced with a defective turbocharger, you should first identify the cause of the problem. In many cases, you’ll need to replace the charge air cooler as well. Read on to find out when and why this is necessary.
Charge air coolers are key components involved in turbocharging gasoline and diesel engines. In direct charge air cooling circuits, they sit in the vehicle front between the turbocharger and the engine’s intake manifold, where they cool the hot, compressed intake air.
This increases the oxygen content of the air to improve fuel combustion in the engine. In indirect charge air cooling circuits, the air is cooled by coolant. This second type of cooling circuit has a significantly lower temperature than the engine cooling circuit (approx. 90°C).
Whether direct or indirect, charge air coolers increase engine efficiency and performance.
Fragments in the charge air cooler
The charge air cooler circulates not only the heated air but also everything that comes out of the turbocharger. A turbocharger defect can have many causes: damage due to foreign objects, contaminated oil, a clogged oil or air filter, interruptions in the oil supply, clogged oil return lines, insufficient oil pressure, or excessively high exhaust gas temperatures.
Any of these issues will take its toll on the turbocharger—ultimately leading to mechanical damage.
If this happens, metal swarf or fragments—e.g., from the impeller—can accumulate in the charge air cooler. If you only replace the turbocharger at this point, these metal particles—depending on their size—may find their way out of the charge air cooler, even after a long period of time, and enter the combustion chamber. Once there, they can damage the cylinder running surfaces and exhaust valves or even cause engine damage.
In addition, metal parts that leave the combustion chambers via the exhaust valves can get into the turbine wheel of the new turbocharger and damage it.
Charge air coolers are crisscrossed by narrow pipework. If metal particles get into a charge air cooler, they can’t be reliably removed by cleaning or flushing. That’s why replacement is essential in the event of a mechanical turbocharger defect in order to avoid expensive consequences later on.
Check installation and components
If a turbocharger suffers mechanical damage, you not only need to replace the charge air cooler but it’s also crucial that you check all the components.
Make sure that you inspect the hose lines as well and remove contaminants such as metal swarf. This is the only way to prevent the turbo from failing again. It’s also important to always follow the turbocharger and vehicle manufacturers’ installation instructions.
Take the following points into account when replacing a charge air cooler:
- Check the air intake upstream of the turbocharger for contamination/foreign objects/blockages/cross-sectional constrictions.
- Check the air duct between the turbocharger and charge air cooler for contamination/foreign objects/blockages/cross-sectional constrictions.
- Check the air ducts between the turbocharger and intake manifold for contamination/foreign objects/blockages/cross-sectional constrictions.
- Clean/replace damaged, blocked, or clogged air ducting parts or attachments.
- Replace any seals on the air ducts and coolant connections (in water-cooled charge air coolers).
- Make sure all connection elements fit tightly, there are no leaks, and no excess air is sucked in.
- Check the boost pressure and other parameters in the engine control unit.
MAHLE turbochargers
On the aftermarket, MAHLE offers a wide range of turbochargers for the commercial vehicle sector covering more than 70 percent of fast-moving applications. The range is constantly being expanded, and a corresponding mounting kit is available for virtually every turbocharger. MAHLE turbochargers are manufactured in line with the highest standards, using the latest processes in state-of-the-art facilities.