Has your car or truck suddenly and inexplicably experienced a decline in performance? Your first thought might be, oh, maybe the seals blew. But in reality, you're probably looking at a more common turbo problem—an oil leak.
Most turbos will experience a leak at some point. So long as these leaks are identified and addressed posthaste, they won't cause too much damage to your turbo, but if they remain undetected or untreated, they can result in turbo decline, and eventually, failure. But how do you identify a turbo leak? What causes these devastating leaks, and how do you fix them at the source? Here are some things to check if your turbo leaks oil, so you can get your turbo back to peak performance.
How To Know if You Have a Turbo Leak
You would think that an oil leak would be obvious, but leaks often start off small and are virtually undetectable, apart from a few hard to notice (or easy to ignore) signs. So, what are some signs that your turbo is leaking oil? The most common symptoms of a leaking turbo include a lack of power, random misfires, blue or black exhaust smoke, and peculiar noises.
The blue and black exhaust smoke is the biggest indicator of an oil leak. The other symptoms mentioned can be caused by a wide range of engine and turbo problems, but blue smoke specifically indicates burning oil due to an oil leak.
Common Reasons Your Turbo Is Leaking
A turbo leak can happen for a wide range of reasons, from a too-small feed and excessive oil pressure. Here we explore some common causes of oil leaks and things to check if your turbo leaks oil.
Which End of the Turbo Is Affected?
Not sure where to start? You can narrow down your list of potential culprits by determining which end of the turbo is leaking.
If the compressor side is leaking, it could be because of:
- A blocked air intake filter, pipe, or hose
- A contaminated air filter
- A split intake hose
- An incorrectly fitted intake pipe or hose
- Damaged compressor housing
- Exhaust system blockages
- Incorrect pressure on the compressor side
If the turbine side is leaking, keep an eye out for:
- A collapsed turbine piston ring
- A warped exhaust flange
- Cracks in the turbine housing
- Incorrect pressure on the turbine side
- Leaks in the exhaust system
- Low-quality or incorrect gaskets
If both sides are leaking, the source could be:
- Excessive beading clearance
- High oil pressure
- Incorrect gasket
- Increased crankcase pressure
- Physical damage to the rotating parts
- Too much oil
- Twist or bent oil return pipes
- Worn piston rings or bores
But more generally, some of the most cited causes of turbo leaks are caused by the following.
Small Feed Line or Return Line
The turbo and turbo bearing require a specific amount of oil flow in order to operate smoothly. Generally, a journal bearing will use more oil than a ball bearing. The feed lines and return lines are what feed oil into the bearing housing and later drain it away. If these lines are too small, it can result in leaking. This usually occurs because oil gets stuck trying to exit the bearing cartridge, thus leading to blockages.
It's important to note that "oversized" feed and return lines won't cause leaking, because it's impossible to truly oversize these parts. The larger the feed and return lines, the more oil they provide, and the better they return oil to the pan.
Poorly Routed Return Line
The return line should provide a downward path to the oil pan. If the return line has uphill routing or spots that are level or damaged in any way, shape, or form, it can lead to problems such as leaking. Rerouting the line normally solves this problem, but in cases where the line can't be rerouted, you can install an oil scavenge pump instead. These suction-powered pumps remove oil from the drain line to keep it clear.
Too Much (Or Too Little) Oil Pressure
Too much oil pressure can result in seal failure, and as a consequence, leaking. But too little pressure can also be catastrophic to the seals and other internal parts of the turbo.
An Angled Center Bearing Cartridge
Most bearing cartridges can be tilted to a certain degree, but problems can arise if they're tilted too much. It's much more difficult for oil to leave the drain flange when the bearing cartridge is slanted, which can lead to build-ups, blockages, and eventually, leaks.
How To Prevent Turbo Leaks
Do you have a turbo that's leaking like a faucet? You'll need to determine the source of the leak and take the necessary actions to mend the problem. Don't want to deal with a leak ever again once this one is fixed? You can't completely erase the chance of getting a turbo leak, but there are measures you can take to make them less likely.
Don't worry; these measures aren't costly or time-consuming. In fact, most of them are simple and straightforward. To prevent future leaks and expensive repairs or replacements, make sure to regularly:
- Inspect the oil system for blockages
- Ensure there are no leaks in the exhaust system
- Never use silicone on oil gaskets, since it can become detached and block oil passages
- Make sure the diesel particulate filter (DPF) and the catalytic converter aren't blocked
- Check to ensure the housings have the correct oil levels and are using the correct pressure
You also want to make sure your turbo components are top-notch and in excellent condition. Always use the correct kind and standard of gaskets, O-rings, turbine housings, and compressor housings. By taking these precautions, you can stop oil leaks in their tracks.
Unfortunately, a leak caught too late can destroy your turbocharger. It can be devastating when your turbo fails on you, but there is one upside—you still have the opportunity to replace that turbo with a newer and better one. If you're looking for new, used, rebuilt, or refurbished turbochargers for sale after a fatal leak or simply because you want to upgrade, come and check out Turbo Turbo's selection of reliable and high-quality turbochargers and turbocharger parts today!