A well-maintained turbo can last as long as the engine it's fitted to. Most turbos that fail early are killed by something preventable: oil, dirt, heat or a fault elsewhere on the engine. Here's how to avoid all four.
1. Oil: the right spec, on time, at the right level
The turbo shaft spins at well over 100,000 rpm on a thin film of engine oil. Nothing else on the engine depends on oil quality as much as the turbo does.
- Use the exact specification in your manual, not just the right viscosity. Many modern diesels with a DPF need a low-SAPS oil (for example ACEA C2/C3 or the manufacturer's own approval). The wrong oil damages the DPF, and a blocked DPF damages the turbo.
- Change the oil filter at every service. A cheap filter or a blocked filter starves the turbo just as surely as low oil does.
- Check the oil level every couple of weeks. A falling level is an early warning, whether from oil consumption, a leak, or oil getting past the turbo seals.
2. Use the severe-service schedule if it applies to you
Most manufacturers publish two service schedules: normal and severe. In South Africa, many vehicles fall into the severe category without their owners realising. Severe-service conditions include:
- Regular towing or carrying heavy loads
- Gravel roads and dusty conditions
- Mostly short trips or stop-start town driving
- Fleet, delivery and work use with a lot of idling
If that describes your driving, shorten the service intervals to match. Your turbo will last much longer for it.
3. Keep dirt out: air filter and intake
At turbo speeds, a grain of sand hits like a bullet. The compressor wheel takes the damage first.
- Check the air filter often on gravel or farm roads, and replace it more often than the schedule says if it's dirty.
- Use a quality filter that fits properly. A cheap filter that doesn't seal in the airbox lets dirty air straight past it.
- Check intake hoses and clamps for cracks and looseness, especially after any work in the engine bay.
4. Use the right diesel
Modern diesels with a DPF are designed for low-sulphur diesel (50 ppm or 10 ppm). Higher-sulphur fuel increases soot and ash. That loads the DPF, raises exhaust back-pressure and makes the turbo work harder and hotter. Use the grade your manufacturer specifies, buy from reputable sites, and replace fuel filters on schedule. Contaminated diesel damages the injectors, and poor combustion from damaged injectors ends up as soot in the turbo.
5. Cool down properly, but don't overdo it
Switching off a hot engine stops the oil flow while the turbo is still at extreme temperature. The oil left in the bearing housing cokes, and you get bearing wear and blocked oil passages.
- After normal driving: no cool-down is needed. Driving gently for the last minute or two is enough.
- After towing, a long climb or hard highway running: idle for 30–60 seconds, and up to two minutes after very heavy work.
- Don't idle for long periods. On modern diesels, extended idling builds soot, loads the DPF and dilutes the oil with fuel.
6. Warm up before working hard
Cold oil is thick and flows slowly to the turbo. Drive gently until the engine reaches operating temperature before you tow, overtake hard or climb at full power. You don't need to idle to warm the engine up: gentle driving does it faster and better.
7. Let the DPF do its job
The DPF regenerates (burns off soot) during sustained driving. If the vehicle only ever does short trips, it never gets the chance, and the DPF and VGT vanes slowly fill with soot.
- Take a regular 20–30 minute run at steady highway speed if most of your driving is in town.
- Don't switch off during an active regeneration if your vehicle shows one, for example with a raised idle or the cooling fan running.
- Don't ignore a DPF warning light.
8. Avoid lugging and treat the engine sensibly
Turbos are built to work under load, so towing and long trips aren't the problem. Labouring the engine is: being in too high a gear at very low revs under heavy load. Change down and let the engine rev. If your vehicle has been tuned, make sure the tune stays within the turbo's safe limits. Overboost and excessive exhaust temperatures shorten turbo life fast.
9. Don't ignore the warning signs
Have your vehicle checked promptly if you notice:
- A whistling, whining or siren-type noise
- Blue smoke (oil) or excessive black smoke
- Loss of power, or limp mode
- Oil in the intercooler pipes
- Rising oil consumption
- Boost-related fault codes or a check-engine light
Have the fault codes read before anyone condemns the turbo. A boost leak, a faulty sensor, a sticking actuator or a blocked DPF can make a healthy turbo look like it has failed.
10. When the turbo does need replacing: fit it properly
This is the most important section on this page. Most "new turbo failed" complaints come down to how it was fitted, not the turbo itself.
- Find the root cause first. That might be oil starvation, contamination, a blocked drain or breather, foreign objects, or a DPF or EGR fault. If you skip this step, the new turbo will fail the same way.
- Replace the oil feed line and flush or replace the drain line. Don't reuse carboned lines.
- Change the oil and oil filter, and check that the breather system works.
- Clean the intake and intercooler. Debris from the old turbo will wreck the new one.
- Use new gaskets and the correct fasteners. Never use liquid sealant on oil lines, because excess sealant can block the passages.
- Pre-fill the turbo with clean oil through the feed port before fitting the line.
- Prime the oil system: crank the engine without starting it (with the fuel disabled) until oil pressure builds, then start and idle for a few minutes while checking for leaks.
- Calibrate or set the electronic actuator if the turbo has one, following the correct procedure.
Need a turbo or fitting kit?
Turbo Diesel Components supplies turbochargers, CHRAs, actuators, oil lines and gasket kits for passenger, commercial and industrial applications. Search our catalogue or contact our team for help.