Slight engine stutter when AC is running?

[select20]

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.

[Tcoat]

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.

[FRSBRZGT86FAN]

Originally Posted by select20

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.

Originally Posted by Tcoat

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.

[Sigh-on-Rice]

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.

[humfrz]

Originally Posted by select20

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.

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

[Ultramaroon]

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?"

[select20]

Originally Posted by humfrz

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

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

Originally Posted by Ultramaroon

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?"

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.

[select20]

Originally Posted by Tcoat

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.

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.

[Ultramaroon]

Originally Posted by select20

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.

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.

[humfrz]

Originally Posted by select20

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.

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 ......


humfrz

[Muaddib]

Idle at 2k rpm and you will be fine.

[select20]

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

[FX86]

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

[humfrz]

Originally Posted by FX86

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 ........



humfrz