2021 tundra a/c clunk noise on start up

Was just curious if anyone else is experiencing a loud bang noise on start up
Sounds like a cats under the hood and is jumping into the hood on start up
I know it sounds silly but that’s the best way to explain it

 

It's common. Seems to happen when cars cold and been sitting for few days. Other makes do it too. Lots of theories but no consensus. Seems to not be an issue though.

If you turn on ac before you crank it won't happen.

 

I live in Florida and it seems worse when it was cold outside
I have had a 2008 and 2018 tundra neither of those had that noise
It just doesn’t sound very good and normal
And concerns me from a brand new truck

 

Is it a split second sound like a grind?

 

Mine does that too sometimes, especially if I haven't used it in a while.

 

It’s a loud bang noise
Like something is hitting the hood real hard

 

I don't have that in mine.

 

I'm from WI and it's gets pretty cold here. Drive my truck maybe only twice a week. I never heard anything like that before.

 

I don’t drive my truck often but I consistently have gotten that “thud” when turning on the AC since I purchased it in May of 2020. It’s especially loud the longer the truck sits unused…

 

I always turn ac off before turning off truck and I still get it if it sits a few days

 

You bring up an IMPORTANT point that I didn’t add…it only happens when I forget to turn the AC off when shutting down. Which for me is about 25% of the time.

EDIT: I should not have used the word only. It significantly quieter is more accurate (turning on AC after truck started).

 

Mine does it too when I start it up after leaving it alone for a night or two. Seems to be when I turn on A/C. No issues with it, just that initial ‘umph’.

 

I'll take it. No rodents at least.

 

The noise is caused by compressor oil collecting in the compressor and upon initial compressor
engagement, the compressor must pump the oil out causing the “Bang” noise. Compressor
engagements thereafter are normal and less audible as the collected oil has been pumped out.

RECOMMENDATIONS
This is a normal characteristic and no repairs are recommended.