Engine Won’t Turn Over
One of the rudest shocks in the morning is to wake up and discover that while your car ran just fine yesterday, this morning it’s as lifeless as decaf coffee.
Fortunately, when an engine won’t turn over it is typically due to 5 common causes:
• The battery is dead or dying
• The anti-theft immobilizer (if your car has one) is malfunctioning
• The neutral safety switch is bad or your shift lever is not in place correctly
• Have a blown fuse or relay in the electrical system
• The starter is dead or dying
And this is fortunate, because all of the above causes are within the abilities of a DIY home mechanic given a few tools and some basic instruction.
The following is summary of what you should do before calling a tow truck or mobile service center to take care of your problem. For more details, check out the ChrisFix YouTube video below that offers one of the best video tutorials I have ever seen not only for telling what to do, but how to do it safely.
Stay in the Car First-Things-First Approach
When diagnosing the causes of your problem, I would recommend following what I consider to be a first-things-first approach, chief of which is investigating what I can that keeps my hands and clothes clean until I really need to risk getting some smudge on myself when away from home. Plus it’ll save yourself from some embarrassment as I will explain below.
Make Sure the Shifter is in Place
Much to my embarrassment, this actually happened to me once. I got distracted while parking my car and failed to shift the lever completely into park before turning off the engine. When I returned to the car and it would not start, I spent a good half hour messing around with the battery until I realized that the neutral safety switch was not engaged because I had the automatic shift lever between Reverse and Park. Doh!
Check the Dash Warning Lights
Another keeping clean first-things-first approach is to turn on the key and pay attention to what your dash warning lights are doing. Depending on the model of your car this may differ, but typically the warning lights will all come on briefly and then shut off when things are normal. When things are not normal, however, a warning light may flash repeatedly without turning off, trying to get your attention.
If for example, your car has an anti-theft immobilizer system it should flash repeatedly on the dash display if there is something wrong with it electronically or with your key fob. A check engine light as well may flash continuously if there is some other electrical problem, in which case you should check your car’s manual.
Time to Open the Hood
At this point, it’s time to open the hood and take a look at what else could be going on. The majority of the time the problem is with a dead or dying battery; or, battery post corrosion that is preventing electrical current from flowing from the battery to the starter. In either case, a good start is just to look at the battery cable connectors for obvious corrosion, and give the battery cable connectors a twist to see if they are loose and causing a poor connection.
I would recommend checking this link on how to assess a battery problem for more battery-related details when a dead battery might be your problem.
Another quick check under the hood is to go the fuse box and see if any of the fuses are blown. In addition, checking the relays usually situated beside the fuses by turning the key and listening for an audible click within the relays is a clean and simple way to narrow down the diagnosing of why your engine will not turn over.
Time to Crawl Under the Car
Once you’ve pretty much eliminated the above sources of potential problems, now is the time to crawl under the car. Going back to the safety neutral switch, you can go to the wiring that connects the switch to the transmission to see if the connector is still in place and has not been damaged.
And while you are doing that, it is also a good time to check the wiring that connects to the starter to be sure that the wires are firmly screwed onto the starter terminals and have not loosened causing a poor connection and thereby failure to turn on the starter.
If all appears fine, then there is a good chance that your starter is dead or dying. I say dying because if the problem is with worn armature components, sometimes just by repeatedly turning the key, a starter will engage enough to start the engine.
In fact, in the ChrisFix video, Chris recommends giving a starter a few whacks with a hammer to coax a worn starter to engage, but this really is a stuck-in-the-middle-nowhere Hail Mary attempt to get your engine to turn over and started so that you can make it home or to an auto parts store to buy a new starter.
When The Starter is the Problem
When all of the aforementioned first-things-first items have been examined and tested, that leaves a worn starter as the likely problem to why your engine will not turn over. The good news is that in many models of cars, this is still a DIY car repair job most car owners can handle on their own.
For this part, I will refer you to the ChrisFix video below as he offers the best demonstration I have ever seen on how to replace a car’s starter that includes safety practices and practical tips for getting to that notorious third bolt that makes starter removal a headache and knuckle buster.
How to Diagnose and Replace a Starter
Caveats to the Video
One caveat to the video is to note that the terminal connecting bolts on a starter are made of copper; and as such, will easily strip its threads if you attempt to tighten the nuts on it too tight. It is best to tighten the nuts just a quarter of a turn past snug and no further.
Another caveat to the video is to be sure to check the cable running from the battery to the starter to make sure it has not broken or cracked from wear and heat due to riding against the engine block.
For more DIY car repair articles, be sure to check out the following links about “Transmission Problem Diagnosis With This Simple Tool” and “What You Need to Know About Mixing Car Tires.”
COMING UP NEXT: Save money by knowing when to hire it out and when to do it yourself.
Timothy Boyer is Torque News automotive reporter based in Cincinnati. Experienced with early car restorations, he regularly restores older vehicles with engine modifications for improved performance. Follow Tim on Twitter at @TimBoyerWrites for daily automotive-related news.