AC stops working when I rev the engine (live data video)

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, Tim, JohnHere

Post Reply
zafirovp
Posts: 2
Read the full article
Joined: Sun Jul 07, 2019 5:42 am

AC stops working when I rev the engine (live data video)

Post by zafirovp »

Hello,

I have Audi A6 from 2006. When I rev the engine past 2000 rpm the AC stops working. If I rev the engine again I hear a hissing sound and the AC starts working normally. I made a video with live data. As you can see from it, the gas pressure drops immediately after I rev the engine and the evaporator temperature rises rapidly. Any ideas what is causing the issue.

https://www.youtube.com/watch?time_cont ... mzufjhHgRM
User avatar
Cusser
Preferred Member
Posts: 849
Joined: Sun Apr 24, 2016 6:29 am

Re: AC stops working when I rev the engine (live data video)

Post by Cusser »

zafirovp wrote:Hello,

I have Audi A6 from 2006. When I rev the engine past 2000 rpm the AC stops working. If I rev the engine again I hear a hissing sound and the AC starts working normally. I made a video with live data. As you can see from it, the gas pressure drops immediately after I rev the engine and the evaporator temperature rises rapidly. Any ideas what is causing the issue.
Nice computerized thingee, but I want to go back to basics. Is the compressor clutch actually engaged over 2000 rpm, take a look. And if not engaged, is that AC clutch getting 12 volts positive?
zafirovp
Posts: 2
Joined: Sun Jul 07, 2019 5:42 am

Re: AC stops working when I rev the engine (live data video)

Post by zafirovp »

As far as I know this is clutchless ac compressor. The only thing that is engaging is the AC regulating valve n280.
User avatar
Tim
Site Admin
Posts: 1117
Joined: Tue Apr 12, 2016 2:19 pm
Location: Scottsdale, Arizona
Contact:

Re: AC stops working when I rev the engine (live data video)

Post by Tim »

This compressor has a clutch hub. Just hidden.

Image
------------------------------
Please support ACKITS.com for your Auto A/C Parts and Tool needs.

Help Support the Forum
User avatar
bohica2xo
Preferred Member
Posts: 1170
Joined: Wed May 11, 2016 4:12 pm
Location: Las Vegas, NV

Re: AC stops working when I rev the engine (live data video)

Post by bohica2xo »

No RPM readings in the video, so it is hard to determine what is going on there.

The regulating valve never moves and a pressure sensor shows what may be the high side going all over the place.

Without actual system pressure from both the low & high side & an RPM reference it is all guesswork.

Since you have three different vent temperature sensors, I would wonder about a control system issue / sensor failure.

When you increase engine speed, the compressor capacity increases. the high side pressure should increase, the low side should drop - and the control valve should shift compressor capacity to manage things. You appear to have a swing of over 120 psi on the high side with no change in control valve setting.

Sounds like you may need a dealer level scanner.
Post Reply