Does replacing a turbocharger require an oil change?
3 Answers
Replacing a turbocharger does not require an oil change. Function of a turbocharger: The turbocharger operates using engine exhaust gases. The exhaust passes through the intake housing, where the nozzle ring increases airflow speed and lowers temperature. It then flows at a specific angle through the impeller blades, driving the rotor to rotate. The exhaust further increases speed and cools before being expelled, which can also be considered as a scavenging effect on the turbine side. The co-axial compressor wheel draws in fresh air, which becomes high-temperature and high-pressure after passing through the inducer and compressor wheel. However, the air density is still low at this stage. The air then passes through a diffuser to lower its temperature, and most of it is further cooled by an intercooler. This increases the air density, thereby achieving the purpose of increasing air intake volume. Turbocharger removal steps: Before disassembly, mark the corresponding positions between the compressor housing and turbine housing, as well as between the turbine housing and bearing housing. Loosen the compressor housing clamp screws and remove the housing. After removal, inspect the compressor wheel for damage. Mark the corresponding positions between the turbine shaft tip, compressor wheel, and shaft nut. Do not erase these marks during cleaning to avoid imbalance during reassembly. Loosen the turbine housing clamp bolts and remove the turbine housing. Inspect the housing surface for cracks and the turbine blades for damage. Use a wrench to hold the turbine end head, then use another wrench to loosen the shaft nut. Twist the impeller left and right while pulling it upwards to remove the compressor wheel. Gently tap the compressor shaft end with a wooden hammer to extract the turbine shaft. After removal, inspect the shaft neck for signs of burning or wear, as well as the relative positions of the sealing rings in their grooves (the correct position is with the ring openings offset by 180 degrees). Remove the heat shield, loosen the backplate bolts, and remove the backplate and O-ring. Inspect the O-ring for damage. Remove the oil baffle and thrust bearing plate, checking the oil grooves and holes on the thrust bearing plate for blockages, and inspect for any crushing or cracking. Remove the thrust washers, spacer sleeve, and bearing retainer ring, checking for signs of burning. Extract the floating bearing and inspect the wear on the bearing, as well as the inner and outer surfaces of the bearing housing. Also check the wear on the sealing rings and clean any carbon deposits from the bearing housing oil return cavity. Remove the shaft seal sleeve and sealing rings, ensuring the sealing ring openings are offset by 180 degrees. Inspect the wear on the ring grooves and the weakening of the sealing ring tension.
I think replacing the turbocharger definitely requires an oil change because the oil circuits of the turbocharger and the engine are interconnected. When removing the old turbocharger, metal fragments or impurities are often mixed in the oil. If you install the new turbocharger without changing the oil, those contaminants can get into the bearings or gaps between components, causing scratches or blockages. A new turbocharger is very expensive, and if it breaks, you'll have to spend more on repairs. Engine oil is much cheaper—just a few hundred bucks for a change, and replacing the oil filter at the same time is even safer. I've seen this happen several times—owners who skipped the oil change later ended up with squealing or leaking turbochargers, and their engines suffered too, doubling the repair costs. That’s why whenever I work on this, I insist on a full oil change to avoid future trouble. For daily driving, maintenance is a small investment—don’t risk big losses over minor savings. Also, check the oil line seals to ensure there are no leaks, so the entire system stays reliable.
Last time I had the turbocharger replaced, the mechanic insisted on changing the engine oil too. At first, I was reluctant—the old oil still looked pretty clear. But then I learned that turbochargers operate at high speeds, and the oil doesn't just lubricate; it also helps with cooling. If the oil contains impurities, heat transfer efficiency drops, and the turbocharger can easily overheat and fail. Real-world cases show that after installing new parts, circulating old oil can introduce contaminants, leading to reduced performance at best, or seizing and complete failure at worst. I regret not changing it sooner. Now I've learned my lesson—I always replace the oil and filter. The maintenance costs add up, but it saves you from major repairs. A car is like a partner; treat it well, and it'll last longer. Oh, and after the change, take a short drive to check the oil pressure and make sure there are no leaks in the system.
