Factors effecting long term engine life.

The following is a copy of a document I wrote for a Volvo forum in the UK, but it might be of general interest and applies to most car engines except some modern hybrids. ENGINE LIFE FACTORS There are three basic areas to consider when trying to figure out how to make your engine last as long as possible before requiring a major rebuild. All of them are roughly as important in engine life terms as each other. TYPE OF USE What type of use your car is subject to in terms of the amount of time spent stuck in traffic jams or cruising on a motorway is very important. Motorways are good for an engine, as some of the carbon deposits in the cylinders and exhaust system tend to burn off and because the engine stays nice and warm, no new deposits form. The oil temperature will also be high enough to evaporate any fuel contamination and to clean the internal oil pathways more efficiently. Getting stuck in traffic is a real horror story for any engine type except a hybrid. The cylinders get dirty from incomplete combustion products and that effects the wear of the rings, cylinders and exhaust valves in particular. Having to do a lot of stop start driving is never good news and the more short trips you do the more wear your engine is subject to. Shutting down for a short while is not as much of an issue as shutting down for enough time to cool the engine down. Oddly enough driving on dirty roads is also bad news as no air filter is perfect and Silicon crystals that are small enough to pass through the air filter will not be caught by the oil filter and are one of the worst contaminants of engine oil. Every engine has a certain amount of blowby, so traces of fuel or dirt entering the cylinders will always show up in the engine oil. DRIVER STYLE A lot of people know that drivers with a big right foot like the average boy racer wear out their engine faster, but the story is more complicated than just considering how hard you accelerate or how fast you stop. About half of the wear an engine is subject to results during the first cold start of the day, when even an 0W rated oil is too thick to fully protect an engine. Any use of the accelerator during start or for about 30 seconds after start is very bad news and it also bad news to use high revs before the engine is fully warmed up, which might take as long as 10 minutes driving in winter. Switching off a turbo charged engine suddenly without allowing the bearings to cool down is also unwise, although it tends to cause much more damage to the bearings that are spinning at incredibly high revs when the oil supply stops, than it does to the rest of the engine. Most owners manuals say at least 2 minutes at idle is required before shutting down from a high power run. OIL AND FILTER CHANGES Failing to change the engine or filter before it degrades or the filter blocks is obviously a negative factor, but the story is a rather more complex one and involves determining the best oil and filter change intervals to suit the use and driver style your car is subject to, in addition to the condition of the engine. It makes very little difference which major brand or even type of oil you choose, but it does help to choose the right viscosity range and most older V40’s should be using 5/40 engine oil (Although Mobil do list 0/40) and nearly all major brand oils will fulfil the requirements listed in the owners manual. In general terms you get what you pay for and buying supermarket or oil brands you don’t recognise from e-bay is not a good idea. The major oil companies like Liqui Moly, Castrol, Mobil and Shell all have web sites with oil finder guides to help you select the best oil. The quality of the oil filter is as important as the quality of the engine oil and buying a real Volvo one is money well spent. The difficult part of optimising your oil service procedure is not which oil or filter to buy, but when to change them. Blind obedience to the recommended oil service interval is not the best idea unless your engine is in very good condition, not subject to any kind of severe service use such as traffic jams and you are using a top quality manufacturers recommended oil, which for most Volvos means an expensive fully synthetic oil. In general terms if the Volvo recommended oil & filter change interval is 10K miles, then if your engine is in poor condition, you spend a lot of time driving in a city or have to do a lot of short trips then half the figure to 5K miles. If you have an old engine in poor condition and spend a lot of time stuck in traffic, then reduce the interval further to 3K miles. Oddly enough changing the oil filter too often is not good as a dirty filter is more efficient than a clean one right up until the moment the oil pressure relief valve opens. So if you are changing your oil every 5K miles, there is in fact no real need to change the oil filter until the full manufacturers recommended change interval I have used in this example of 10K miles. Strangely enough changing oil too often is also bad news as the oil that is always left behind during an oil service tends to interfere with the function of the new oil additives for a while, so if you change your oil too often you increase the wear factors and not reduce them. Topping up the oil is good, as apart from reducing the risk of running out if the engine develops a leak, the extra additives in the new oil help top up those in the old oil when oil is added in small amounts. OIL ANALYSIS I am a fan of Blackstones the main oil analysis lab in the US and send off a sample of used oil every 20K km when I do a full service on my 1.9D (I change oil only at 10K km) and for 25 dollars they e mail me a full report showing just what condition the oil is in so I can figure out if I am changing oil too late or wasting money by changing it too early. They also comment on the what condition my engine is in and even list a set of averaged out results for the F9Q block for me to compare with. I am using an expensive fully synthetic oil at present, but because I am not pushing the boundaries of the 20K km recommended oil change interval and my oil analysis results are good, I will switch to using a cheaper conventional oil next year. The proof of the pudding is always in the eating as regards the results from the mass spectograph used to count the parts per million of the different wear metals in used oil and I will then cross check the results from the cheaper oil next year, just in case it turns out the fully synthetic oil is better. IN CONCLUSION The engines used in most V40’s are based on main blocks chosen because they are capable of a very long life if not abused and well maintained. Unfortunately very few engines reach the 300K plus type figures that are very possible if you can stay on the right side of all three main factors that effect the life of an engine. My own car suffers a lot of short stop starts and driver abuse, but it only uses half a litre of oil between services and produces oil analysis results that have half of the average wear metal figures, so the previous owner must have driven like a granny mostly on the autobahn (Grannies drive quite fast in Germany). PS: Don't forget the cam belt service or the lower radiator hose clamp, as a lot of cars finish up in a scrap yard because their cam belt failed or the engine was fried. --------------------------------------------------------------------------------
 
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Originally Posted By: skyship
About half of the wear an engine is subject to results during the first cold start of the day, when even an 0W rated oil is too thick to fully protect an engine.
You're assuming that it's a lack of oil flow that causes initial startup wear, but that's not necessarily the case. Here's a post from another member from a thread that covers the subject.
Originally Posted By: edhackett
Quote:
So if it's not that oil flow is less right after start up, then what causes wear?
The largest contributor to wear when cold is the fact that the operating clearances are not to specification. Different metals expand at different rates. Until the engine is fully heat stabilized the clearances are off. The most striking example is pistons being oval. They are machined out of round so that as the various thicknesses of metal heat up the piston achieves a round shape. A cold piston can have clearances that are four to five times normal operating clearance on one axis. Some anti-wear additives are not effective until the oil warms up. Rich mixtures wash oil from cylinder walls. This is less of an issue with fuel injection, but is returning as a real problem with direct injected engines. Ed
The thread can be found here and is a good read: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2145915&page=1 Other than that, I think your post is pretty good.
 
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When did Blackston become the "main oil analysis lab" in the US? I would take Polaris/UOA over B/S any day, and I believe given the choice between B/S and Polaris most industrial or commercial mechanics would also choose Polaris. Has there been any testing to verify that driving on dirt roads causes excessive engine wear?
 
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Originally Posted By: Donald
Has there been any testing to verify that driving on dirt roads causes excessive engine wear?
I noticed this too, and my own experience concurs with what some OEM's have actually put into manuals that OCI should be decreased when driving in "dirty, dusty" conditions. Many of you guys know I go offroading quite a bit. A few years ago I did more street time (as opposed to trailer) and ran more unmaintained roads than usual. My UOA had a spike in sodium (but not K) & a bit of silicon and Gary, myself, and a few others thought it was from driving on these old dirt roads that had been severely salted in winter. Despite my sealed, solid filtration, it still managed to get in my engine. The next UOA after that season showed sodium had returned to normal. Engine "wear" had remained pretty normal though! Better safe than sorry?
 
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Agree except for the oil analysis. Basically useless for the average person in determining whether an engine will go 100,000 0r 300,000 miles. too many variables, inconsistent lab interpretations and in most cases there is nothing you can do about the wear except change the oil every 2000 miles which is not a solution just a cover up. In the long run, on today's cars, something other than the engine will be the cause of the vehicle's demise. we simply overthink oils and OCIs today when it is rare the engines are the reason we dump a vehicle at some point.
 
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Originally Posted By: Spector
Agree except for the oil analysis. Basically useless for the average person in determining whether an engine will go 100,000 0r 300,000 miles. too many variables, inconsistent lab interpretations and in most cases there is nothing you can do about the wear except change the oil every 2000 miles which is not a solution just a cover up.
Yeah, I agree with this. Remember BuckGN's good UOA with half a piston in the pan? His oil condition was good though!
 

skyship

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Originally Posted By: Spector
Agree except for the oil analysis. Basically useless for the average person in determining whether an engine will go 100,000 0r 300,000 miles. too many variables, inconsistent lab interpretations and in most cases there is nothing you can do about the wear except change the oil every 2000 miles which is not a solution just a cover up. In the long run, on today's cars, something other than the engine will be the cause of the vehicle's demise. we simply overthink oils and OCIs today when it is rare the engines are the reason we dump a vehicle at some point.
It is definitely worth doing an annual UOA as it is rather like an insurance policy in detecting fuel or coolant contamination in addition to faulty air filtration. Even if you think you will be able to detect such contamination of the oil without a UOA, it is good to do a single UOA with TBN included just to confirm your OCI is sensible or to save some money by extending it. Oddly enough a lot of old engines fail because they suffer additional wear from contaminated oil that could have been avoided by reducing the OCI, which might have been OK in previous years but if you don't do the occasional UOA there is no way of detecting some types of oil contamination. In applications like aviation where the life expectancy and reliability of an engine is of the utmost importance, UOA has been very important for some years and for owners who think of their car or trucks engine is as important as an aircraft one there is a good case for doing them.
 
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"Factors effecting long term engine life." Valve train wear is a factor thats not covered often because it's only a factor for long term engine life. Valve train wear affects engine performance and excessive wear hurts power and fuel economy. What are factors that affect the oils lubricity and anti-friction properties. Contamination, shearing, extended OCI?
 

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Originally Posted By: Zaedock
The OEM's already did the testing, which is why we have recommended oil change intervals.
The trouble is with manufacturers recommended OCI is that they are under pressure from the marketing folks to quote a high figure because it looks good. Obviously they don't quote figures that might cause failures during the power train warranty period, but they don't have much interest beyond such a time period. The manufacturers recommended OCI is based on an engine in good condition not subject to severe duty use and for some odd reason not many manufacturers quote a severe service oil change interval, although those that do seem to quote a figure half the normal one. Many folks in the Volvo forum have old engines not in the best of conditions and spend a lot of time driving in heavy traffic and for those folks using the manufacturers figures is one bad idea, as they often need to cut their OCI to 3K miles which for reasons I do not understand is still popular in the US. In the UK they seem to use 5 or 6K miles and the Germans use 15 or 20K km as a general figure, so you have to consider the OCI habits of the nation concerned as they are different.
 
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", as they often need to cut their OCI to 3K miles which for reasons I do not understand" Motor oil Is inexpensive, and available EVERYWEAR . Even supermarkets like Safeway offer their own brands. Vehicle maintenance is also in the culture, I remember even Dept Stores like Simpson Sears would offer an engine rebuild service for popular engines, 40 years ago, many, many guys were shade tree mechanics. Today, there is not much the average guy can do at home, But he can still change Oil, Just like Dad used to do! :-) In the UK the MoT forces people send there car to a service station once a year, my guess is many people use the opertunaty to get a service and oil chane at the same time (which is proberbly much longer than a 3k OCI )
 
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Change/check the oil on a regular timely basis and don't overheat the motor. Drive moderately. The engines last longer than the owner(s).
 
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Cooling system failures can quickly cause serious damage to an engine. Many people don't appreciate that engine coolant doesn't last the life of the engine. Their mechanic never suggests it either. So their coolant degrades, deposits accumulate, and perhaps one day while driving merrily down the road a hose fails from the pressure. The engine overheats severely. An otherwise perfectly good engine is lost. But their mechanic of 12 years, who sees this car twice a year since new, makes big money swapping in a used engine. A real pity IMO.
 
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