BMW 335i "Engine Malfunction: Reduced Power" - Reasons and Solutions

If you are a BMW fan, you will get a lot of pleasure when driving your 335i. This is a legendary vehicle with a lot of compliments from buyers. Yes, it still has a lot of flaws, and its durability is very questionable, but you are ready to forgive everything once you experience what this vehicle is made for.

Engine malfunction, reduced power message highlights

• Common reasons:problems with engine sensors, software glitches, low battery problems, etc.
• How to fix:turn the car off and on, disconnect the battery, use scanner tool
• Possible consequences:if reset doesn't help, the problem may be serious and require urgent attention
• Priority level:High
• Can you drive?Yes
• DIY repair:Impossible
• Repair price range:$150-$1,000

What does it mean when you see the "Engine Malfunction" error message?

Once you see this message on the dash of the BMW 335i, you will know that something is wrong with the electronics of your engine. It may be a malfunctioning sensor or it may be that the self-diagnosing system located a problem with the combustion process and warns you about it.

Unfortunately, the vehicles at that time weren't as clever as we would want them to be, so they will not deliver you any further message saying what exactly is wrong with the engine. For understanding this, you will have to go to the shop and ask a specialist to use computer diagnostics equipment for reading codes.

Here are the symptoms and features of this error:

• when the error comes on, the vehicle will let you know about it producing a special sound, then the message will appear on the dash: "Engine Malfunction: Reduced Power";
• basically, this means that the engine goes to the limp mode which results in limited power and acceleration and also in numerous minor changes in how your car goes;
• after you turn the engine off and then on again, the error will not disappear, it will still keep the engine in the limp mode for safe driving;
• in most cases, this will save you from any kinds of abusive driving, so you can safely drive to the service station, repair shop, or to a BMW dealer to solve the problem;
• it doesn't always mean that a big problem has happened with the engine, sometimes, it's just about a minor wiring issue or a sensor failure;
• if you don't have any special equipment for diagnostics, you will not be able to clean the error code and make your vehicle work in a general mode.

Well, if you read forums, you may find there some scary information. BMW 335i owners often say that after they saw this error message, they went to a shop and a specialist there told them the engine needed overhauling or something like this. Calm down, this error doesn't always mean something is completely wrong with the car.

But yes, driving and doing nothing with the error is not an option. You have to do something because driving in the limp mode on the BMW 335i is something like a sin in the world of BMW drivers, isn't it?

What problems could have triggered the "Engine Malfunction" error in the 335i?

Well, the problem can be connected with different units and parts, so, we can't point to a certain problem. But we can tell you how to find the issue. You basically have two ways of dealing with the vehicle after you see this limp-mode message:

1. Go to one of the auto parts stores and just buy a simple code scanner. This scanner is able to read a certain code that triggers the message on your dash. Once you have the code, you can google for a unit that causes this problem. In most cases, this simple diagnosis will save you some money and time. A good scanner may cost up to $50 and this is cheaper than one visit to the dealer.
2. Go to a specialized shop and ask for proper diagnostics. You will get all the information on which part is causing problems and how you can deal with the issue. This is much easier for you, but this is not the cheapest way to cope with the problem.

Well, we would certainly go for the first option because we are car geeks. If you are not, then you should probably find someone who will diagnose your car. Maybe, you can do it in your local BMW community because many BMW owners have these scanners and readers.

Now, we'll come up with the most common reasons why the "Engine Malfunction: Reducer Power" message may appear on the dash.

1. Misfiring engine

This is a very common problem for the BMW 335i. Its straight-six engine is really powerful allowing a driver to enjoy 302 horsepower and 400 lb-ft of torque which is great. But the engine is known to be less reliable than it's usually expected by the owners of the 3 Series.

Misfiring may occur because of spark plugs, ignition coils, injection problems, etc. You should check if all those parts work well and don't influence the way the engine works. Well, there are plenty of other reasons why the engine may misfire, so proper diagnosing will be a good idea.

Also, if the problem is in the misfiring engine, the error should occur when you accelerate sharply. After that, after some time, the code may disappear and the vehicle may work well until your next quick acceleration or highway driving.

2. Vanos solenoids

Oh, yeah! These things will get on your nerves after your 335i is over 100,000 miles. We believe nearly all BMW 335i cars are now over this mileage and that's why all of them suffer from this Vanos system. Solenoids get clogged and don't work as they should. That's why the engine works poorly, acceleration may suffer, and gas mileage is not good.

If this is the case, all you need to do is to clean the Vanos solenoids or replace them. For cleaning the solenoids, we know a DIY method:

• take them off your vehicle;
• prepare a cup with gasoline;
• put one of the solenoids into the cup submerging just its working part, not the contacts;
• use any automobile accumulator to send power to the contacts of the solenoid;
• if it clicks quickly, it's working.

Check and clean all the solenoids or better have them cleaned or replaced if you are sure they are the main reason for the error message.

3. Turbocharger issues

One more thing that can go wrong in your car is the turbocharger. We can't say that the turbo in your BMW 3-Series is very bad. But due to abusive driving, it can break down pretty often. Also, bad regular maintenance may be the reason why your turbocharger is not working properly.

If your turbo is getting on your nerves, we are sure you should replace it with a new or remanufactured one. BMW turbochargers tend to ask for a lot of repairs once they start failing.

4. Fuel injectors malfunctioning

This engine has direct injection which is one of its curses. Over time, it gathers a lot of carbon deposits in the intake and this may be the reason for your problem. Carbon deposits are pretty hard to clean, in most cases, you will need to replace your fuel injectors. And there are 6 of them in this engine.

Once injection fails, misfiring occurs. But this is not the only problem. The engine may also develop other problems with poor injection like loss of power, bad gas mileage, numerous error messages on the dash, etc.

5. Engine sensors

One more thing that can malfunction and cause the "Engine Malfunction: Power Reduced" message is one of the sensors. BMW engines have a lot of them and each may fail. It's one of the easiest things for diagnosing because you just need a proper scanner for getting the certain code and seeing which sensor is failing.

In most cases, the best decision is to buy a new OEM sensor and install it instead of the old one. This will get you back on the road.

Final words

We wouldn't continue driving a lot once we see the message saying that the 335i turned to limp mode. The first thing you should do is diagnose the issue and find the proper solution. After that implement that solution and only then you can keep driving your BMW and get pleasure from the vehicle.

Otherwise, a small problem with a sensor or a Vanos solenoid may lead to bad issues with the engine itself. And these problems will be much more expensive to deal with!