Slight engine stutter when AC is running?
 

This only happens when it's like 90+ outside and it's very noticeable. If I'm running the AC at night or when it's not as hot, it never stutters. Also, it's a consistent stutter, like every 3 seconds.

Really curious if anyone else has had this.

Everybody has this. The compressor kicks in and out a lot. Small displacement engines have to struggle a bit. Not a problem so don't worry.

Well known issue, even higher displacement motors I know do this, I've seen coyote powered 2012-2016 mustangs do this as well. It's just the sudden load on the motor. Also our compressors cycle on an off, on what I believe is a pressure based switch, so it may be a consistent on and off engagement of the compressor which is normal.

Mine does this too sometimes. When it does it, it does it for the whole trip. When it doesn't, it doesn't for the whole trip. BUT, mine does it when the compressor kicks in, which is about 10 to 15 seconds. Not 3 seconds.

I just returned from the warm side of our state (98 degrees F) and noticed the engine would "pull down" a bit (especially at idle) when the A/C compressor would kick in, also the idle would be a bit rougher.

If you would call that a "stutter" then yes.

Back-in-the-day ....... a "stutter" would be like a spark plug was fouled...;)


humfrz

If you listen carefully, engine RPM actually drops momentarily when the compressor clutch releases. At least mine does.

Also, every 3 seconds doesn't sound right. Did you mean to type "30?"

This is exactly what it makes me think of, except it only does it when the AC is on.

No I did mean 3 seconds. Maybe more like 3-5, but I'm not exagerating. Only when the AC is running on a hot day. If the AC is going at night, or just when it isn't hot, it never "stutters" or what ever you want to call it.

Also, sorry to take so long to get back, had some "technical" problems. With phone/pc/internet. I think it was the storms.

Ok well, that makes me feel better. Some times it will "stutter" multiple times and the AC doesn't come back on. If it takes a few minutes to kick back on and I start getting hot, I'll just hold in the clutch and rev the engine to 5k+ and it pops back on immediately.

What you're describing sounds to me like what's called "idle hunt" which happens when something throws off the air-fuel mixture in a manner which the ECU is unable to control. The most common is a vacuum leak.

You might consider taking your car into a shop that has a A/C checking/repair capability and have the refrigerant level checked.

Sometimes when a compressor is low on gas, it can give weird signals that might affect the engine.

Back-in-the-day ..... I'd guess that your cooler was low on ice ...... :respekt:


humfrz

Idle at 2k rpm and you will be fine.

Thanks for all the replies everyone. Much appreciated. Will take it to shop and get it checked just for peace of mind.

my A/C always turns off because I can't stop redlining it with the pedal to the floor...then you start feeling really hot...that's how those race car drivers must feel with no A/C i guess

Dang hot rod ........ :slap:



humfrz

it always happens in 1st and 2nd gear...sometimes 3rd..4th gear only in mexico

Please do follow up if you learn anything. Good luck.

AC idle problem
 

Yea like some have said here, its a smaller engine problem, the AC kicking on and off bogs a small motor, mine used to do it all the time sometimes dropping As low as 300 rpm until i bought the Vishnu OFT, now that it has the new software and a higher idle it doesn't do it anymore. The Vishnu tablet was a great upgrade and puts the idle where it should be, around 800, these motors idle too low from the factory.

Welcome to the forum.

Not every three seconds.

No. 650 RPM has been a standard for many decades.

Yea mine wasn't every 3 seconds but each vehicle no matter if the same model and make varies in operation. And yes an average of 650 rpm has been a staple for an idle for a few decades, but it doesn't mean that its a great idle for these engines. Mine before my Vishnu tablet install would idle as low as 500 occaisionally and would feel like it wanted to stall, especially when i would put the AC on.

If u turn on the AC but turn the fan speed down low it can happen that often. The compressor will kick on and off at low fan speed. If the fan is turned high the comp will stay on and it'll only have a one time bog when it kicks on the first time. If it's bogging and u see the compressor staying on then it's not the AC doing it