2008 Explorer - Car starts, drives but then won't start later but then starts again magically

[AzaWaza]

I'm hoping you can help me since I'm not finding anything with my google searching or even a way to best say the problem.

Car: 2008 Explorer XLT 4x4 with about 135K miles.
Major work: rebuilt transmission in Jan 2020
Minor work: new interstate battery April 2020
TL;DR problem: Car has begun a pattern of randomly not starting and then without any work, starts fine later.

Problem:

First noticed in March 2020. My mother drives this car and she went to visit my brother and his family. When she went to leave that evening, the car wouldn't start. After playing with cables and cleaning off some corrosion, the car started. She drove home and parked. She drove the car another trip or two without problems. Then when leaving for an appointment, the car would not start again.

Since we live in Arizona and batteries just die, I replaced the battery with a new one in April. Once that was done, the car would still not start.

Behavior when trying to start: All lights come on and the key turns. There is no clicking sound or attempt to turn over the engine.

Also - There are no lights on if the car starts. Diagnostic says all systems are fine. No lights come on when driving.

After the battery, I had a mobile mechanic come take a look. He cleared the cables, the starter and the alternator. His diagnosis was a loose wire on the starter - he did some bypass type test and the car started right up. Repeated this multiple times. Disconnected his bypass and car would not start. He tightened this wire and left.

Car was used two times for running around (not many places to go in lockdown, right?) and there was no problem.

Went out last week and the car is again not starting. Same behavior.

Trying to get the mobile mechanic out.

Car has been sitting untouched since about Wednesday of last week. Went into the garage last night and tested the car and it started right up. Again, nothing has been done or the car even moved.

I'm at a loss on what this could be. Maybe the wire came loose again? Could it be a fuse? Has anyone ever heard of this before? Could the transmission job have messed up something?

What would cause a car to not start then start later just fine?

This has been a great car and it's still in really good shape. I drove it for a number of years and gave it to my elderly mother a few years back when I got a newer vehicle. It's not driven a lot anymore.

For the record, I know just enough about cars to mildly protect myself at a mechanic. I don't do any repairs. Replacing the battery and topping off fluids is about as aggressive as I get.

 

[MotorCityFats13]

wow this is crap..... do you have 2 or more keys and does it do this with all programmed keys also when you turn the key on and let it sit does the security light turn off... this would rule out a pats issue other than that I would suspect a starter issue but when you turn over the key and it doesent start can you hear the fuel pump turn on

 

[AzaWaza]

wow this is crap..... do you have 2 or more keys and does it do this with all programmed keys also when you turn the key on and let it sit does the security light turn off... this would rule out a pats issue other than that I would suspect a starter issue but when you turn over the key and it doesent start can you hear the fuel pump turn on

Good idea on the keys! I would not have thought of that. I tried my second set and no difference.

I'm not sure how to tell if the fuel pump is working or not. The security light is not on when the car is running.

My regular mechanic said it sounded like a starter or solenoid problem. I could have sworn I replaced one of those a few years ago, but guess parts just wear out.

I tried to look at what fuses may control the starter, but I'm not sure how to tell if they are bad or not.

Thank you for your reply. It was helpful.

 

[MotorCityFats13]

if it starts then the security light would definitely go out but if you turn the key forward and not start it and the light stays on then the system is not accepting the key... and when it wont run have somebody put their ear under the truck by the fuel tank and listen for the pump whine and after about 3 seconds it will turn off when pressure builds

for people that love fun stuff you can jack it up place the key in the run position and find the 2 12v+ posts on the starter and bridge them with a wrench or 2 if it starts then its a relay or the solenoid

 

[3C24]

Double check the battery cables. Even the slightest kink can do it. From personal experience.

 

[WaltZ]

similar thing happened to me. Go into a store for a while, come out and turn the key - nothing. Waited 15 - 30 minutes more and it turned right over. For me, it was a bad starter

 

[BamaRaised]

Had a similar issue with our 2010 for quite some time. Multiple mechanics and the dealership could never find the problem. For some time we thought it was a starter relay overheating, so we kept extras to swap out, as it seemed to happened more often in the summer, and it seemed to work most of the time, for a while at least. Anyway, it finally got to the point where I couldn't stand it anymore as it was happening more and more frequently. After a couple of days of troubleshooting the starter/switch and literally everything in between, I stumbled across what I thought was a loose fuse. Turns out it was a thing called an OTIS (One Touch Integrated Start) diode. The slots that it sat in had become loose over time and caused a failure to crank/start. I fixed it by taking the fuse box apart and simply compressing the slots so they made solid contact with the pins. It hasn't happened since. If everything else has failed you may want to check this. I haven't heard of anyone else having this issue though.

See if the OTIS diode has any resistance when you try to remove it.

You may want to test your starter relay as well, make sure the pins are clean. There are tons of videos on testing relays, it's pretty simple.

 

[fingers crossed]

I suggest it may be the starter solenoid.

What you described has happened with a few vehicles I've owned including an 09 exploder.

A quick way to check requires 2 people and a ratchet or crowbar or something to use to tap on the solenoid while another person turns the key.

While one person is turning and holding the key attempting to start engine, tap repeatedly on the side of starter solenoid being careful not to hit the wires or electrical terminals on the front end of solenoid.

If this works, the contacts within the solenoid are likely corroded or pitted from arcing to the point they can no longer make consistent electrical connection.

Depending on your particular model of starter, there may be a replacement solenoid available. I replaced the entire starter assembly with a reman part from local auto parts store. Took about 45 minutes.

Hope that helps.

 

[ashner19]

I'm hoping you can help me since I'm not finding anything with my google searching or even a way to best say the problem.

Car: 2008 Explorer XLT 4x4 with about 135K miles.
Major work: rebuilt transmission in Jan 2020
Minor work: new interstate battery April 2020
TL;DR problem: Car has begun a pattern of randomly not starting and then without any work, starts fine later.

Problem:

First noticed in March 2020. My mother drives this car and she went to visit my brother and his family. When she went to leave that evening, the car wouldn't start. After playing with cables and cleaning off some corrosion, the car started. She drove home and parked. She drove the car another trip or two without problems. Then when leaving for an appointment, the car would not start again.

Since we live in Arizona and batteries just die, I replaced the battery with a new one in April. Once that was done, the car would still not start.

Behavior when trying to start: All lights come on and the key turns. There is no clicking sound or attempt to turn over the engine.

Also - There are no lights on if the car starts. Diagnostic says all systems are fine. No lights come on when driving.

After the battery, I had a mobile mechanic come take a look. He cleared the cables, the starter and the alternator. His diagnosis was a loose wire on the starter - he did some bypass type test and the car started right up. Repeated this multiple times. Disconnected his bypass and car would not start. He tightened this wire and left.

Car was used two times for running around (not many places to go in lockdown, right?) and there was no problem.

Went out last week and the car is again not starting. Same behavior.

Trying to get the mobile mechanic out.

Car has been sitting untouched since about Wednesday of last week. Went into the garage last night and tested the car and it started right up. Again, nothing has been done or the car even moved.

I'm at a loss on what this could be. Maybe the wire came loose again? Could it be a fuse? Has anyone ever heard of this before? Could the transmission job have messed up something?

What would cause a car to not start then start later just fine?

This has been a great car and it's still in really good shape. I drove it for a number of years and gave it to my elderly mother a few years back when I got a newer vehicle. It's not driven a lot anymore.

For the record, I know just enough about cars to mildly protect myself at a mechanic. I don't do any repairs. Replacing the battery and topping off fluids is about as aggressive as I get.

I had this problem as well. Thought it was a battery issue or fuse. It turned out it was the starter. It would lock up and not allow the engine to turn even after starting minutes before. After letting it sit for hours it would eventually start. Once i figured out it was the starter i would crawl under the the explorer and hit it with a wrench and it would start. I bought a new starter but after a few times of hitting it when it wouldnt start the problem went away before I replaced it. I think the gears in the starter were getting stuck somehow. Worth looking into. Good luck