4 Cylinder engine problems

Study finds increasing problems with 4-cylinder engines

In its most recent Vehicle Dependability Study, J.D. Power found an industry-wide increase in vehicle problems for the first time in 15 years. The vast majority of the problems are with 4-cylinder vehicles.

In its most recent Vehicle Dependability Study (VDS) J.D. Power and Associates found that engine and transmission problems were on the rise. Looking at the data more closely the study reveals that the issue is really with 4-cylinder engines and the transmissions they are powering.

The study looks back three years to 2011 model year vehicles. It polls drivers and asks what problems they have experienced. The study then ranks vehicles, automakers, and defects in a scale of problems per 100 vehicles (PP100). In other words a score of 68, the best score which Lexus received, means that 68 problems were reported for every 100 Lexus vehicles. A lower score is better on this scale. This year marked the first time since the 1998 study that vehicles' problems grew overall on average in the industry. So what changed?

Over the past two decades, but much more in the past five years, automakers have been shifting away from V8 and 6-cylinder engines. Instead they are turning to 4-cylinder engines in general, and 4-cylinder turbocharged engines for performance oriented vehicles. The reason most commonly given for this by manufacturers is fuel savings. Mandates by the federal government have forced automakers to start reducing fuel usage overall. However, our own look at the move to 4-cylinder engines, particularly turbocharged engines, shows that when compared to modern 6-cylinder designs there are very few examples where the newer 4-cylinder matches both the fuel economy and power of a newly designed 6-cylinder. The smaller engines can do one or the other, but rarely can match both.

In any case, the study found that 4-cylinder engines have increased their problem rate by nearly 10 problems per 100 vehicles (10 PP100). That is a very significant jump. J.D. Power found that this problem by itself accounted for almost all of the 7 PP100 increase that the overall industry had. The study also noted that large diesel engines were higher in their rate of problems. Commenting on this increase David Sargent, vice president of global automotive at J.D. Power said "Automakers are continually looking for ways to improve fuel economy, which is a primary purchase motivator for many consumers, particularly those buying smaller vehicles. However, while striving to reduce fuel consumption, automakers must be careful not to compromise quality. Increases in such problems as engine hesitation, rough transmission shifts and lack of power indicate that this is a continuing challenge."


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I find no mystery here. Higher compression, higher RPM shift points, and a small displacement engine running at higher temperatures = trouble in the automotive world. Back to the drawing board. An E-CVT would remedy some of the problems but not all. Internal combustion engines and the modern cookie- cutter car has an " appliance" shelf life.
Meh. I do not think most 4 cylinders should be turbo, a lighter-weight, less expensive, clutched, multistage or dual super-charger would be better. The real problem probably has to do with lighter materials and new mechanical designs, post-recession economics effecting quality, and perhaps, in preparing for better efficiency standards where 4 cylinder systems had been underdeveloped because they already got decent mileage. Four cylinder horsepower and torque has increase in the last decade, while remaining fairly efficient. V8 and V6 vehicles have become lighter and blocks improved, this explains why they may be running better efficiency as of late versus the good old 4 cylinder. It seems the largely static EFI systems in 4 cylinders have been redesigned with improved efficiency modes that could explain lag, as well as with changes in lower grade gas. Transmission design might be at fault with the increase in HP in these cars while also needing to run in efficiency mode. Turning a more capable, higher hp transmission can create problems for lower hp efficiency modes. Just a couple thoughts.
Thanks to Parks and CTCusick for these comments. That people with your depth of knowledge are reading my work and taking time to comment makes my day. I appreciate it.
This report quotes, "...smaller 4-cylnder engine problems reported typically are that “The engine hesitates, the automatic transmission shifts roughly, and a lack of engine power.” I wonder if the J.D. Power report separates out reliability problems from these drivability concerns. I find it odd that such concerns would noted in a "Vehicle Dependability Study."
You make an excellent point. Having filled out JD Power studies I can tell you that they want to know if owners took the vehicle to a dealer for a problem. If so, they want to know what the problem was as best the customer could describe it. In the case of the 4-cylinder engines, customers complained that the vehicles didn't seem to run properly. Call it poor design or an unenjoyable driving experience. Either way, customers are not happy and the trend is clear. Thanks for adding this.
I have faced the same problems with I-4 engine mentioned in this article. Recently i got a Camry ( it has the same 3.5L V6 engine used in the lexus models: 2GR-FE). What a difference in the acceleration, smoothness and noise. I dont think i am going back to 4 cylinder again!
It's all about sturdiness in the long run, the same way a diesel might be more expensive to purchase, compared to a petrol unit, it has a number of advantages that, if driven properly will really improve fuel comsumption and increase shelf-life. What, with most of the streets today being filled with more cars than they were originally meant to support, with the solution being to reduce the number of vehicles, change the structure or people adopting more public transport, but I do find myself loving cars too much to abandon them all of a sudden even if it meant it would reduce emissions yadda yadda.
I believe that the low-friction internal components, exceptional synthetic lubricants and engine management systems such as Honda's direct injected i-VTEC technology changes the game. It's quickly becoming a non issue as all major auto manufacturers look to fewer cylinders, supercharging and turbcharging as a reliable method of energizing personal transportation. Did you ever think we'd live in an age of high performance 4 cylinder Cadillac, Ford, etc? It's all changing.
Actually i'm surprised to see somebody is surprised that 4 cylinders are problematic !!! 4 Cylinders are rubbish , that's no surprise and not breaking news , one just has to make a little study to find out 4 cylinders are naturally, greatly lacking in balance and smooth operation ,guess what that causes your engine to wear and crumble over time , and don't start with the Toyota and Honda make some good 4 cylinder S*** blah blah blah , here they're all over the place in repair shops ! and yet i see so few and almost none 6 cylinders manufacturers make your car smooth by installing shock absorbers and balance shafts on the engines to absorb all the vibration that goes into the cabin , but it can't make the engine naturally balanced and vibration-free , that's the basic nature of Inline 4 Architecture , it never goes away , and i think turbocharging them to do the job of a massive V8 engine makes it even worse ... it's just environmentalist pushing them hard, and them using the opportunity to make a big profit out of it by selling you, cheap 4 cylinder turbocharged pieces of crap with the price of a say V6 , and in the name of "FUEL ECONOMY OF A 4 CYLINDER AND THE POWER OF V6 " no no no, let me make this very clear , it's the production cost of a 4 cylinder and the profit of a V6 !!! it's the price of a V6 car for the Crapiness of a 4 cylinder with a lot of environmental bull**** on side... 4 cylinders can never replace V6 or V8 , they aren't smooth , they lack the quality , they lack the charisma and characteristics , and the whole fuel economy and environmental friendliness seems to be only a Hype . they don't really make a huge difference.
4 cylinders can be harmonically balanced by putting balancers on both ends of the crank turbo chargers put a hit temp hi rpm hi cost fan which needs cooling and oil changes done on a timely manner, it will not be done by the normal owner. auto makers like this because they like 2000 dollar repairs in their dealer s turbo could be avoided by putting in light weight cranks, piston rods, pistons, and cams but this we eliminate the 2000 dollar turbo repairs and provide a 300,000 mile engine
My Toyota Echo is noisy and if she drives smoothly or not depends on the roads...lol...I avoided an accident a couple years ago by going up on the sidewalk, which meant my front end hit the curb really hard, over the front lawn of this business and then down off another curb...bottom line is that my tires/rims were fine and I had a mechanic look my car over and he said the front end was tight...I was shocked my car was fine after that incident!...my car can go fast like 130 km and she sounds quiet...when I'm on smooth roads, my car drives smooth as silk...quite frankly, she's reliable as heck and I love the fact I can drive all month on about $25 of gas...my car has power, I've passed 6 cylinder vehicles on the highways and I just look over and grin, the person was probably thinking what was that that just went by me LOL...what's the point of having all this so-called power when, if you use it, you risk getting a speeding ticket?...most people with powerful vehicles do want to show off...I just care about getting from point A to point B.
KK, i am glad that you are happy with your ECHO. You should have stopped before you started with the ignorant statements about passing 6 cyl cars. I have passed Porche 911's, which simply and only says that i was driving faster. Did you get a ticket when passing this 6cyl car? Where you showing off?Lol how do you know why people buy what they buy. Are you jealous of these folks.
I think it's the dealer that benefits the most from the repairs. I think the manufacturer adds the turbo to extract more power while still meeting CAFE regulations. Mazda probably has the best approach with their Skyactiv technology --- tweak everything for lightness and efficiency to pick up a small percentage increase in many places. Probably costs them more in engineering time, but probably provides a more reliable product. I've also read that one of the reasons so many manufacturers are going to CVTs to get better mileage is that they cost a lot less than many-speed conventional automatics. Of course, the customer's fuel savings all go toward increased maintenance of the CVT. I'm coming to the conclusion that a Mazda3 with manual transmission is one of the best cars today.
The car companies will sell you anything, currently they are all trying to sell you the engine configuration from an 80's Group B rally car ...minus the free mechanics..when it goes wrong it is gonna cost ya big time.
The biggest problem I see here with almost eveyone's comments and comparisons is the expectation that a 4 cylinder should perform like a v6 or a v8. Let's start comparing apples to apples here folks. I've driven 500hp v6's supercharged, 350hp v8 hemi's, and 1000hp 4 cylinders and each had advantages and disadvantages. When I bought my little 4 cylinder, in no way did I expect that little car to run like my v6 minivan or expected my v6 minivan to run like my v8 hemi 300. It would be ludicrous to do so. Drive a 4 cylinder like it was meant for and accept the noise/vibration (very little in my car) and you'll have an engine that can easily run 400k with no issues. Drive it and expect v6 performance/vibration (and yes, most even fire v6's are naturally unbalanced and require measures to lower the vibrations) and you will be disappointed.
Turbocharged 4 cylinder : very high torque per piston, high torque variation during 1 engine cycle (>200% overshoot). NA V6/L6 : moderate torque per piston, moderate torque variation (<150% overshoot). NA V8 : low torque per piston, low torque variation (<100% overshoot). Now, consider the flywheel has to be lightened : these torque variations will go right in the gearbox. The gearbox itself is designed for a given maximum torque, which a turbocharged L4 will largely exceed with its spikes if not considered -> it should come equipped with a massive gearbox and/or flywheel (flywheel being highly inefficient since its effect grows with engine speed, while peak torque is at low-mid revs), eliminating its advantages in weight and efficiency. That's not even accounting for clutch slipping, and having killed one in 60000km with an insanely powerfull NA 80hp 4-pot, I know there are cost cuts here too. The result is V6 should be mainstream, perhaps even small (<2000cc) turbocharged V6 for comfort reasons (low rev torque = large useable band) and fuel efficiency (low load = no boost = small NA engine). Simulation helps determine "optimal" dimensions, a typical B segment car needing less than 50hp max cruising power would therefore require a 800~1000cc engine, no wonder why everybody (Ford, PSA, Renault, FIAT) chose to design various 900~1200cc turbocharged engines, and you'll find kei cars (turbocharged 660cc) somewhat comply with this, too, being lighter.