RPM drops when A/C turned on

MIRZA AHMER

MEMBER
2017 SUZUKI WAGON
1.0L
3 CYL
2WD
MANUAL
14,000 MILES

It is summer in my country and AC is a must. But I am having troubles with the rpm. In the morning I first let the engine get running for a minute or so and then turn the AC on at 2. The rpm drops to 500 and then after jumping between 500 to 800 gets normal after a while. Sometimes while driving when AC is on and I brake the car and press clutch rpm drops to 500 and car vibrates this shouldn't happen usually. I faced this situation a few miles back and get the throttle body serviced everything went normal. It is happening again. And even when engine is in running condition and I turn AC to 4 rpm jumps between 500 and 1200 continuously for a while. What is the reason and how to get it fixed? Video attached below when engine is hot and AC is switched to 4. PS: air filter and spark plugs are timely changed.

Video (Click to make bigger)

1 Reply

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

What this looks to me like is probably an vacuum leak. When your engine rpm's are hunting" like that, it's almost always a vacuum leak. I have included a link down below for you to go to:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please go through this guide and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros