My Lincoln Aviator won't start, is it the battery?

Today's question is following our No-Start Diagnostics theme, an aspect of our cars that often comes with many unanswered questions.

"Hi there. I'm having some problems with my aviator. I just bought it private and it seems to be fine when I looked at it. Then I got it home and the next day I cleaned the inside and then wanted to go into town but it wouldn't start. I turn the keys and all it does is a clicking noise. So I boosted it and it runs fine until I shut it of again and leave it for about 20 min then it does the same thing. I'm wondering if it has something to do with the battery?  I thought it could be the alternator but that would mean as soon as I boost it and take the cables off it would slowly die on me again which is not the case. Please help me before I spend more money on a mechanic.
Thank you so much!"

Dear No-Start-Navigator, 
        Thank you for your question! In this instance, while I wouldn't rule out a potentially dying battery, I would say your alternator is the culprit in this case. You are correct that if the alternator was completely bad, the car would slowly run out of juice after being jumped, but that's often at the extreme end of life for an alternator, and most folks get it replaced before it gets that bad. In this instance, if it were your battery and the alternator were fine, it would start charged up for a couple of days at first, and then for at least a few hours and then slowly get to the point of not starting at all. This would be pretty noticeable in it's symptoms.

Obviously, there are elements that I could only diagnose through looking at your Lincoln myself, but just from your description, I would definitely go to the alternator first, as that's what the symptoms point to it right off the bat.

If you have tools available to you, or someone who does, you can do a basic check in both your alternator and battery using an voltmeter. It should be 14.5 for the alternator and around 12.5 for the battery.

Alternatively, you could also take the alternator and battery into a local auto parts store and have them load test them, most do it for free. It'll cost you a little bit of time, but save you money in the long run.

Let me know how things go!

Yours truly,

The Free Mechanic

Is it time for a new battery?

After writing a hub about 5 potential signs that your car battery is dying, I've had an influx of messages and emails asking about different combinations of symptoms and their connection or non-connection to a dying battery in various vehicles. 

"Hi, just read your excellent article on diagnosing battery problems. One symptom I didn't see was the one that's happening to me right now.....the car won't start and my speedo and rev counter needles are going haywire. This just happened out of the blue. Is it time for a new battery???"

Dear Haywire Gauges, 
           
       First, thank you for your question! 

Here's your answer: Having the speedometer and rev counter gauges go haywire, is not necessarily an indication of a bad battery, but it can indicate a connection issue or it could just be sensitive gauges. In some vehicles, the moment you start the car, the gauges will fluctuate when the engine starts, even if the car isn't moving or the engine isn't being accelerated.

In this instance, without knowing more, my first stop would be to check the battery cables and terminals. Even a minutely loose terminal connection could cause the car to not start. You'd be surprised at the list of potential no start symptoms that are caused by loose, corroded or old terminals and cables. Some of them are downright strange.

Make sure that the terminal posts are not loose themselves and that they are corrosion free. Then check the terminal cables and make sure they aren't too old and worn out, and that when you tighten them onto the terminals, they cannot turn at all. It's also wise to make sure the cable wires are still in good shape and fully connected to the terminal connectors.

Once you've checked all that, if the car still will not start, then it's time to check the battery out. A simple way to do that, is to jump start it. If it will start up and stay running without the jumper cables, let it run for 45 minutes to an hour, even drive it around close to home if you want, and then turn it off for fifteen minutes. Then you can check to see if it will start again. If it doesn't, then it's definitely time to replace your battery.

Alternatively, if even jumping the vehicle won't get it started, then there are other components you'll want to look to, such as your starter or fuel pump.

Let me know if you have more questions or need any more assistance! 

Yours truly,

The Free Mechanic

My first question! Nitrous & Compression Ratio

Alright! I must first say much love to the first question asker, you are awesome (and you know who you are!)

Now, the question is "Will running nitrous at 5 pound wet boost, change my compression ratio of my engine?"

To start out on the right foot, I must admit that Nitrous boosting is not something I'm extremely familiar with, so please do correct me if you think I could have provided a better answer. I sought some help from a few mechanics who know this topic better than I do, and the short answers is NO, using nitrous (wet or dry) will not change your compression ratio.

While it seems logical that nitrous would change your compression because it changes the speed at which your cylinders hit the "boom" (combustion) cycle, it does not effect compression at all. What it does, is to make better use of the compression you have, instead of changing it.

Nitrous does effect your timing though, and it has been suggested that you should retard your timing a few degrees depending on how much pressure your exerting during a boost.

Welcome to my new blog, where I have decided to offer my skills as a mechanic and educator. With this blog I intend to give you in depth consultations for free, to help you get through any transportation troubles you may be having.

You can leave a comment on this blog, or come get social on the facebook fan page  The Free Mechanic, and leave your questions for me to answer. I can help with DIY repair advice, diagnostics and estimated-reasonable price quotes. I have plenty of friends who can help me answer other questions about your vehicle accessories as well, so don't shy from any question simply because it isn't listed here!


Just remember to leave your vehicle make, model and year, and what city you live in. This will help me get specific stats for your vehicle, including contributing environmental factors. I can't promise my help will be perfect, but it will be free and will at least bring you one step closer to finding your fix.