Please help, 2018 Mustang GT weak starts sometimes

[hope5oh]

Hey guys I'm still experiencing weird/bad start ups when starting the car. This tends to happen only when the car is warm and has not happened during cold starts. After 5-10minutes of driving and parking at the parking lot, I would get weird startups that sounds like my car isnt gonna start but eventually does.

The noise started 4 days ago..
I decided to do a 2nd gear pull going 35mph when the car ended up losing power (dont believe I was redlining), out of panic I shifted from S to D and the car was fine.
I pulled over and turned my engine off to take pictures of the car when I noticed that my cooling fan was working hard, I owned a 2016 Mustang GT before this so I knew it wasnt normal. I understand that the fan would run a few minutes after engine is off but the fan was really loud.

Here are video clips of the weak startups that only happens from time to time. First one you can hear a click when you turn it on, second and third video you can hear it struggling to start. I also added the fan working hard clip:

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[moosestang]

I would start by making sure the battery terminals are clean and making a solid connection. Then load test the battery. I've had both conditions cause problems with a warm stsrt.

 

[hope5oh]

I would start by making sure the battery terminals are clean and making a solid connection. Then load test the battery. I've had both conditions cause problems with a warm stsrt.

Hey, thanks for your response. The car is currently at the shop and the mechanics are trying to replicate the sound. They seemed to have tested the battery and thinks they're okay. Odyssey battery was replaced August 2022.

 

[hope5oh]

friendly bump.. car still makes one click when starting

 

[Mad]

What ended up fixing it I have a similar problem with mine 1st start in mornings usually perfect. After driving and then starting vehicle get a very weird start rpms rise to like 500 then 1000 then 1500 and then idles like it normally should in normal range. The whole slow start sequence doesn’t late but maybe 1-2 seconds. @hope5oh

 

[Cobra Jet]

Usually with a slow start it could be 1 of 2 things:

- high resistance within a wiring harness that is causing a short

- bad starter. There’s been threads in here about S550 starters going out.

Today's mechanical parts don’t last. So If you can’t find any issues with the wiring, the connectors in the main starter harness, no issues with battery, and battery cables are not deteriorated, then replace the starter.

If running LT headers, LT headers are known to cook starters over time. Wrap the header in appropriate heat shielding AND there is also a wrap for starters too. Summit Racing or JEGS sells the wraps.

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