Technical Idle surge and exhaust rattle when under electrical load

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Technical Idle surge and exhaust rattle when under electrical load

Gman88667733

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Something I've been noticing for a while, in traffic with the wipers on, the engine idle surges and pulses a bit. Noticed it more today as I purchased an alternator tester which required you to put all accessories on in the car and the idle surged with the hazard lights, Everytime they came on it surged. Also the exhaust rattle I mentioned is only really when in the same scenario. Starts and stops with the accessories. I'll attach a video clip if the file size is okay...

Turns out it doesn't, I'll try and format it and try again!

Either way, it's very strange

I was investigating it because on warm restarts the engine cranks for a good 2-3 seconds longer before starting. Starts instantly when cold

The idle surge may well be normal because it's such a small engine, but the exhaust rattle that is in sync with it is perculiar
 
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Poor battery would be the first thing I would look at.
Most cars surge a bit when the electrical load suddenly changes but a poor battery doesn't help.
 
Okay. I have a receipt for a battery change in 2017, so I'd have thought it should still be okay...

It doesn't really bother me that much, may just ignore it
 
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