My Car Makes Fluttering Noise When Starting: Reasons and Fixes

If your engine makes a fluttering noise when cranking, the problem is most likely with the starter motor, solenoid, or ring gear on the flywheel. Locating this issue and repairing it is not a DIY job for most of us. But if you have some technical knowledge, you should be fine if you decide to repair the issue.

Starting engine noises highlights

• Level of urgency:High
• Can you drive?Mostly, yes
• DIY inspection:Almost impossible
• DIY repair:Impossible
• Price for repair:$250 - $900
• Common Reasons:Starter, flywheel, engine problems, belts, pulleys
• Ways to fix:Inspect everything that rotates when starting the car, replace the broken units

How to understand the type of fluttering noise?

In this article, we'll be talking about the type of noise that appears when you crank the engine. This is the fluttering metal noise that is hard to ignore. It seems that something is badly broken in your engine when you hear it. But then suddenly the car starts and the engine runs as smoothly as it should without showing any other problems.

But the scenarios may be different. The nature of the sound depends on what exactly is broken.

Here's what you may need to take into account:

• Do you hear the noise constantly when the engine is being cranked? If so, the problem may be with the starter motor itself.
• Does the engine still start? If it doesn't start, then the bendix gear may be just grinding the ring gear without actually turning it.
• Is the sound permanent? If you hear the sound every time you start the engine, the problem is with the starter or gears. But if it disappears and then comes again, it may be the solenoid.
• Do you hear strange noises when the engine is running? The starter may get stuck with the flywheel and this is a serious issue.

Unfortunately, just understanding the nature of the sound doesn't allow you to make any certain conclusions on what is going on under the hood of the car. You may be pretty sure though that if you hear the fluttering metal sound when cranking the engine, this is exactly the starter-flywheel issue and you should dig in this direction.

Again, I want to warn you that repairing the starter motor without any experience is not the best idea - you can end up having the broken starter in your hands and no idea on how to repair it.

The common reasons for fluttering noise in your engine

To locate the problem, you need to know where to look. We've already come to the conclusion that the fluttering noise is all about the starter motor unit. But there are several possible reasons why this can bother you in your car.

Let's see what can be the reason:

1) Bendix gear is worn out

The bendix is the part of your starter that connects it to the flywheel. This part moves left and right. In one position it touches the ring gear and rotates the engine. But when the engine is started, the bendix sharply moves to the side and it shouldn't touch the flywheel anymore. If it does, you will have a broken starter by the end of your short trip.

So, the bendix may get in the wrong position and it can get stuck. Also, its gear may be destroyed which will also lead to the fluttering noise forming when you are trying to start the engine.

Fortunately, replacing the starter bednix is not that hard, in the majority of the vehicles. But you will still need to take the starter motor off the car which may take some time.

2) Ring gear on the flywheel

The starter cranks the engine by gripping its flywheel. For this, the flywheel has the ring gear on it and it's exactly the ring gear that comes in contact with the starter motor bendix gear. The ring gear is almost never broken in cars. But if your bendix gear is damaged, the ring gear may slowly get damaged, too.

If the ring gear is broken, things are not that good, You will need to have the transmission removed to get to the flywheel and replace the ring gear. This is a labor-intensive and quite expensive job.

3) Starter mounting problems

Your starter is mounted with the use of several bolts. All of them should be tightened with the proper torque. Otherwise, the starter may move when trying to crank the engine. Changing the position of the starter motor to even several millimeters will result in complete disaster when trying to start the car.

To check the bolts that hold the starter motor in place, you will need the torque wrench. If you don't own one, it's much easier to go to the nearest independent shop or dealership and ask one of the mechanics to do this. The checks will take 2-3 minutes and won't cost you a lot (or maybe even will be free for you).

4) Starter solenoid

It's not uncommon for starter solenoids to go bad. These parts are not eternal and they can get broken because of contact with water or just because of the age and mileage of the car. The solenoid actually commands the bendix to move and it can give wrong signals to the equipment.

Replacing the starter solenoid is easy, in the majority of cars, but again, you should do this only if you know what you are doing. Otherwise, your starter motor may be broken right after the next time you start the engine.

5) The starter motor itself

In cars with more than 150,000 miles, the original starter motor may be completely worn out. Trying to repair it is not the best idea, so you may want to just replace this unit whenever you hear a fluttering metal noise when cranking the engine. It's quite obvious that there are many parts in the starter motor that can go bad. So, the repair may eventually cost you more than the replacement.

Also, buying a cheap aftermarket starter motor is not a good option because such units won't last long and may not be reliable enough.

6) Bad battery

It's worth checking the battery voltage. If the voltage is low, the starter may not get enough power and it may crank the engine intermittently. This may be the source of the fluttering noises, especially in some older models of engines.

If the voltage is lower than 12.2 volts when the car is off, the battery should be recharged or replaced.

Can you still start the engine when there are fluttering noises?

Well, the question is pretty hard. If you are stranded in the middle of nowhere and the night comes and you are afraid that coyotes can come from the desert and have a good snack eating you, then it's worth trying to start the car in this condition.

But if your vehicle is now in the garage or in the parking lot near your office, it may be more reasonable to leave it there, use a taxi, or some other way of commuting and when you have more time, you may get the vehicle directly to the dealership or a good repair shop.

If you try starting the engine, you may get several serious problems:

• the broken starter motor may damage the gear ring on the flywheel;
• the bad bendix gear may eventually kill the entire starter motor;
• the starter motor may get stuck which will lead to additional issues;
• the battery may die leaving you without any chances to start the car.

I would only try starting the vehicle if there was no choice. Like if I'm on the highway and there is nobody who can help me, I will try starting the engine whatever sounds it makes. In all other cases, I would just call for help.

Repairing the fluttering metal noise in the engine

While it may feel really complicated to repair the starter motor, sometimes, the repair is easy. You need to locate the problem and then decide if you can do all the work on your own. Even if you decide to take the vehicle in for repairs, you will know the problem and will save some money on inspections.

Anyway, if your experience doesn't allow you to confidently repair the starter motor, you should go to specialists and have the problem solved for you.

Sometimes, the repair will be pretty expensive. The starter motor may cost you a fortune if you need to replace it entirely. Also, the labor will still cost some money. I strongly recommend OEM parts if you want to ensure that the car is durable and reliable.

Final thoughts

I don't think that the fluttering noise in your engine when you crank it is a very serious issue. But still, it won't allow you to ignore it. The issue may be not so expensive to repair unless you keep driving like that. Once you destroy the gear ring on the flywheel, this is not going to be affordable anymore.

Also, remember that you shouldn't try starting the engine if it makes a fluttering noise. It's much wiser to pay a hundred or two for the tow-truck service but avoid paying a thousand for parts that you initially didn't need.

If you still have questions about the sputtering noise, please ask them in the comments. Also, share your experience in dealing with this problem.