06 Mustang has started taking longer to start, but runs seemingly fine after

I’ll try to give as many details as I can. A little history to start, I bought it in October of 2018 so I’ve owned it for almost 2.5 years with excellent performance. I’ve driven it half way across country twice and it is my daily driver. It’s sitting at 55k miles. No, that isn’t a typo. It had 34k when I bought it from an old lady who had a midlife crisis, bought it brand new and never drove it. She did provide me with all of the records proving that she kept up with servicing, oil changing, all that good stuff and I have kept up on it as well.

It started a week or so ago. Sometimes, but not every time, it will take a few extra cranks or acts like the battery is low when I start it, but does eventually start. The battery is only about a year and a half old. I have no issues with radio, lights, or anything else. Even after sitting with the radio on for half an hour before work. Battery gauge shows normal.

I have noticed no consistency in conditions it happens in. It’s happened in both hot and cold weather. Sometimes it will start fine after being off for 9hrs while I work, sometimes it struggles. Sometimes it will even struggle to start after just being off a few minutes (like after getting gas). Sometimes it doesn’t struggle as long.

Once it’s on, I notice no issues. No overheating. ~25MPG. No surging. No loss of power (and I do climb a very steep hill going to work). Passed Cali smog last year with flying colors. No apparent noise coming from tank area. It DOES have a rough idle sometines, but has had one since day 1 of owning it. It DOES sometimes shift hard, but again, day 1. I did suspect a vacuum leak, because of the idle, the amount of sitting during the last ownership and a little tss tss tss (maybe not day 1, but maybe month 2) noise coming from the engine bay… but it wouldn’t have passed smog if there was one.

I know it may seem minor, but I’d rather fix whatever it is now than end up stranded in the middle of the night on my way home from work where there is no “convenient place” to break down at, possibly even miles from cell service.

I’d start with the basics. Check and read codes. Have the battery tested, make sure the charging system is charging, check and clean both ends of both battery cables. Check fuel pressure and fuel pressure bleed down. Then

If there are any codes then it will be displayed on the console telling you so.

Seems very excessive that this stage.

This is possible. Even on a 1 year old battery. And just because all other electronics work doesn’t mean it’s not the battery. Starter motor draws several hundred times more amps then you car radio or dome lights.

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Years ago when I had a longer commute I was averaging over 40k miles a year. So after 3 years I’d be over 120k miles…55k is really not that high. That’s not even 20k miles a year. During Covid I barely go into the office. But before Covid I was averaging about 25k miles a year.

A LOT of text but little useful information… What engine? What transmission? Is the check engine light on? If it passed Cali smog, it wasn’t on at that time. Have you tried fuel injector cleaner in the fuel tank?

A shop with a good scan tool can plug it into the car and watch what happens when you try and start it to determine why this is happening. I’d attach fuel pressure gauge and a vacuum gauge, too. I suspect a dirty injector or bad fuel pump check valve allowing the fuel pressure to bleed down overnight.

That’s not even 5k miles a year.

OP has only put 20k on in 2 1/2 years.

Ah…20,000/2.5 = 8,000.

But was just responding to his comment about 55k miles being high for a vehicle that’s 3 years old. It’s above the national average, but not really that high.

I think the OP was commenting on how LOW the mileage was… at least that’s how I took it.


It’s a 15 year old vehicle

I have to stop trying to multitask. You are correct. Read it too quickly

V6, Automatic, no check engine lights at all. Could it be a spark plug as well? Last night, it really struggled after getting gas and it was literally turned off less than 5 minutes

Nope, because then you’d have a Check Engine Light.

Test it, don’t guess. You’ll spend time and money and still won’t fix it. If you don’t have the tools or the skills to check fuel pressure and a scanner to read what is happening, take it someone who does have both. Pay them.

It will be cheaper than guessing and just tossing parts at it hoping one might fix it.

I wasn’t saying it is high. The opposite actually. I can’t take it into any shop without the techs having to confirm that the milage is correct. Most would think I meant to type 155k, not 55k. So I just made the clarity ahead of time

“takes a few extra cranks” - do you mean the starter motor has to turn over the engine for a longer time than it used to? Or does it mean you turn the key from Start to Off then back to Start more than once?

“acts like the battery is low” - because the starter motor is turning at a slower speed than it did before? or the speed of turnover is uneven, as if the starter motor is straining at some moments?

Where are you getting that ? They don’t really care about the mileage , they are just going you try and find out the problem .

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