Expert Opinion: How to treat your turbo-charged engine
Today, ladies and gentlemen we have ourselves a new feature…
This is where we will try and answer many/most questions you may have on cars without telling you GFE (Google Effin Exists)…
I will try as much as possible to have an expert in a specific field to answer your queries and keep my 2 bob opinions to myself i.e Body kits are for guys with small ninis… So for any car related queries, comment below, email, tweet or write on our facebook page and we’ll get that addressed.
I enlisted help from ze Master expert, Mista Lobsta…
The admin of the largest & most active car forum in the country, Legends (my opinion) and a well rounded DIY guy who has modded his car on his driveway on a shoestring budget, plenty of ideas and great execution skills.
Without much further ado… #Leego
Expert Opinion: How to treat your turbo-charged engine…
by Mista Lobsta
Many people may own and drive turbocharged cars but few have the faintest clue on how to treat them for a longer service life and worry-free running. Here are a few tips to help you give your turbo-assisted engine the best treatment for that awesome driving pleasure… like a bauss! (-_-)
Engine oil choice
For most drivers/owners, they never know or understand what oil they should use for their engine. What do the letters and numbers on the oil can mean? 15w-40..? 5w-30..? 20w-50..? What are those..?! In a nut shell, and not to sound too geeky, those are the oil temperature handling characteristics; lower- and upper-limit handling characteristics to be more precise. In essence, during manufacturing, the oil is tested for how it would behave/react under certain temperatures, both cold and hot. In both of these situations, the oil needs to have enough flow characteristics to keep your engine bits lubricated, but at the same time, not break down & cease its core function, which is lubrication.
So then, what is light oil and what is thick oil? When you see a ‘W’ on a viscosity rating it means that this oil has been tested at a colder temperature and is safe for use in colder climate regions. The numbers without the ‘W’ are all tested 100 degrees C which is considered an approximation of engine operating temperature… also known as single grade oils. Most oils available in the Kenyan market are multi-grade oils and are cold-rated despite us not needing them given our vehicles never see winter-type climate. It is, however, safer to run cold-type oils to give better cold-start protection
When cold, oil is harder to flow than when hot (as it thins out with increased temp) and this is what creates oil pressure. Contrary to popular belief that the oil pump is what creates the pressure, it isn’t. It only creates flow. The resistance (to that flow) given by the oil galleries and components is what creates the pressure. The older an engine gets and if still using the same oil, the lower the pressure will get at operating temperature since expected component wear and tear will have tolerances altered thus reducing overall resistance to flow.
Ideally, you should always give an engine a few minutes to warm up with light driving in order to preserve your oil circuit/system. Hard-revving an engine when cold will surely give you trouble, either immediately or in the not-so-distant future. Given our local weather patterns and driving culture, here are a few things for you to consider when choosing engine oil. Please note that there is no single oil grade that will work for everyone, for that, one would need specifics to give the best suggestion;
If you drive mostly short distances and in free-flowing traffic, lighter oils would be better as the engine in most cases will not have had time to warm up fully/quickly enough. If you drive hard and are a racy driver, lighter oils will also ensure that even if you decide to ‘hoof it’, your critical components are protected as they will be receiving proper lubrication.
Engine age (mileage):
If you have an older car or one that has covered lots of miles/kms, you are better off going for slightly thicker oil. This is because engine tolerances will have changed given that components will have worn out over the years/miles. A thicker oil ensures that the necessary film of oil keeps them running. The best bet is to run an oil as close to your manufacture spec as possible.
Gasoline- or diesel-powered:
Oil choice will also depend on whether your motor is a gasoline/petrol or diesel-powered one. Modern technology though, allows oil manufactures to develop oils safe to use across the board. Fully synthetic oils are recommended for both engine types.
Oil change intervals
Most people locally have developed a rather bad habit of having and keeping a static service interval of 5,000 km regardless of the cars’ use or condition. I disagree. I would suggest that oil changes be based on either a time- or mileage-chart, whichever comes first. For instance, if you have a car that does 20km at most over a period of more than a month or two, the engine oil will have far deteriorated by the time it hits the 5k km mark. For a daily driver (car), I’d suggest oil change intervals every 3,500 km or 4 to 5 months — whichever comes first. Remember, oil not only lubricates, but cools and cleans your engine as well. You have nothing to lose by running more frequent changes.
With every oil change MUST come an oil element (filter) change. There’s no point of running fresh oil on an old/used filter. These are cheap as chips in comparison to the trouble you’d have if you ran a used filter which then proceeded to clog and starve your engine of lubrication. Most modern fail-safe oil elements will come with a safety bypass that will (still) let oil through should it be used to a point where its element is completely clogged. Better to have an engine running on dirty oil than no oil at all. When topping up the fresh oil, anything above 3/4 and slightly under the ‘F’ mark on the dip-stick will do. Avoid overfilling — this is one of those instances where more isn’t always better…
Like all the other engine components that work together to give you that epic feeling of boost, the most important is the turbo. They spin at ridiculous rpms (Revolutions Per Minute) and handle a lot of heat. Proper turbo lubrication requires the proper oil for the engine application. Without delving too much into how they work, most modern day turbos are both oil- and coolant-cooled. Oil to lubricate and cool it while the coolant ensures that it doesn’t get past its’ safe operating temp, which for most is a sweltering 900 degrees C…
In this regard comes the question about whether or not one needs a turbo timer — which is basically an after-market electronic module that allows your engine to idle for a preset amount of time prior to shutting down (even after you pull the key from the ignition). Whether or not you need one will depend greatly on how you drive. With hard driving on-boost for extended periods, it’s best to have the turbo ‘cool-down’ for a bit. it’s always best to drive off-boost for the last leg of your journey to the point where the car will be parked — this is because compared to ‘cooling down’ while stationary, driving gently will help the radiator and turbo have air flow going over them to further aid with cooling.
The primary concern revolving around this is that if you suddenly switch off a car that has just come from a spirited run, due to the extremely high temps in the turbo (& engine in general), there is a chance that the oil that was flowing through the turbo will literally be ‘cooked’ as it will be sitting (without flow) in the very extreme temperature environment found within the turbo. This can, over time, develop into narrowed oil galleries within the turbo similar to clogged blood arteries because of the sedimentation layers each time the oil sits, ‘cooks’ & layers itself in the galleries.
Because of the extra heat that the turbo setup generates, engine cooling is critical! Always ensure you are running proper coolant* levels and that your entire cooling circuit is in mint form. It will be easy to spot signs of trouble on a turbo-assisted engine as they tend to run hotter than their natural aspirated counterparts. Routine inspection of the radiator hoses, overflow bottle and joints will help ensure that all is well. Every 10,000 km or so, flush the system with fresh fluid… at this point, you should also check that your thermostat is still in proper working order.
*coolant can be water or any other cooling agent, not necessarily, the red-stuff or green-stuff coolant types that comes with our cars
For any engine to make the most power, it will require good fuel. Ensure you get the best locally available fuel for your motor. Remember, you only get what you pay for… 🙂
Good fuel will not only ensure that you get the rated power the engine is capable of, but it will also protect your fuel pump and injectors from unnecessary damage.
Enhancements / mods
At least 2 out of 5 turbo-assisted car owners have modified their vehicles, even if just as simple a mod as dropping in a high-flow air element or just an aftermarket exhaust system. With every modification done to any engine setup, there must be proper and required supporting modifications for them. For instance, turning up the boost level should not just be done without ensuring that there will be proper fueling to support the new boost levels and avoid running lean. Alongside this come other minor checks such as whether your aspiration system (intake and exhaust) will be able to efficiently handle the new power levels, whether your cooling circuit will be able to safely eliminate the extra heat generated etc. If you do decide to modify any bit of the engine setup, ensure it is done correctly so that the engine is still running within acceptable parameters to protect it.
Want your turbo-powered engine to last for as long as it can, here’s what you need to do;
- Get the recommended oil for your setup, and abide by frequent change intervals — this is by far the most important thing you’d want to do.
- Ensure you car stays as cool as possible — proper engine bay ventilation and a properly functioning cooling system will enhance this.
- Drive gently when the engine is cold. For most cars, not revving above 2.5k revs will ensure you are within safe oil pressure thresholds.
- If you’ve had a spirited run, go easy on the throttle for the last few miles/km to allow a controlled cool-down.
Use good fuel & try not to drive on-boost for extended periods when on reserve fuel (very low fuel levels).
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