[Jeroen]

For anybody interested in AC systems. I recently replaced the AC evaporator on my Jeep Cherokee, which is a dashboard out job:

https://www.team-bhp.com/forum/diy-d...ml#post5307858

If you like to get a close up look of a typical AC clutch have a look here, I replaced one of the bearings recently as well.

https://www.team-bhp.com/forum/diy-d...ml#post5366709

[Game_of_Roads]

Originally Posted by true_sedan

My Virtus GT has developed a clicking noise that occurs every 23 seconds precisely. The sound can be heard coming from the engine bay and sounds like metal rubbing against metal.

I have a 1.0AT Slavia and have the exact same sound come up very noticeably even inside the cabin from around 2k kms. Reported this and was told that it's normal operation of the electromagnetic clutch for the AC compressor. Not sure I noticed it earlier though.

I also face a clicking sound when turning the steering wheel significantly at parking speeds.And then there is the brake noise at low speeds, the worst of the lot..

Still, the car is a hoot to drive and a real looker. I guess one should leave their OCD at home while living with this car to thoroughly enjoy it.

While I do question the presence of these issues having paid close to 20 BIG ones, I guess 20L is the new 10L in the crazy priced automotive world right now..

[safedrive9]

Originally Posted by vividhavasthi

I had the same experience and it's the AC for sure. While driving in a particular gear and the AC engaging I too have felt a small jerk.

Get the AC checked and gas levels etc, once I got my AC fixed (low gas level) this issue slowly went away - but not completely. Try to keep the AC on auto at 22, this was the most optimal setting for me.

Hi, Need help here. My 1.0 Taigun is having the same issue. AC Compressor is switching around 4 times a minute. There is a small jerk while driving too.

Was this issue resolved for others.. If so what was the fix done.

[vividhavasthi]

Originally Posted by safedrive9

Hi, Need help here. My 1.0 Taigun is having the same issue. AC Compressor is switching around 4 times a minute. There is a small jerk while driving too.

Was this issue resolved for others.. If so what was the fix done.

Have the system checked for low/high gas levels at the service centre. Also, have you got the AC software update? My car had low level of gas and that's why the compressor was misbehaving.

[safedrive9]

Originally Posted by vividhavasthi

Have the system checked for low/high gas levels at the service centre. Also, have you got the AC software update? My car had low level of gas and that's why the compressor was misbehaving.

Thanks for the response. Yes, AC software update was already done. At that time I have asked the VW service center to check the gas levels. I am not sure if that was done. In my case there is no issue with the cooling, but compressor is switching frequently. In this case if cooling is OK, will there be issue of low gas level?

I am thinking of taking it to the service center again to check the gas levels and may be the pressure sensors and thermostat too.

[safedrive9]

Originally Posted by true_sedan

Update: Took the car to the service centre and the service advisor(my regular guy) said that the compressor noise is normal with all MQB vehicles. He explained that the minor jerk can only be felt at low rpms and speeds which is not true. I explained this to him and he wanted the car to sit in the service centre for a couple of days so that he can diagnose it extensively. He further added that the jerk is caused by a drop in engine power which then the engine compensates by increasing power causing the minor jerk as rightly said by BHPian Jeroen.
Even the SA was of the opinion that VAG group has severely downgraded the quality of not only the externals like plastic fit and finish but also the internals especially the AC and its components.
The very reason I got the Virtus GT was because I loved the sheer driving pleasure I got from driving my cousins 2.0L TDi Jetta. That is a gem of a motor. Creamy smooth at all speeds and takes on corners like there is no tomorrow. I only wish VW had put similar care in making their 2.0 cars for India. Not only VW but most cars below 25 lakh OTR sold in India nowadays don’t feel premium like the cars of yesteryear(pre-Covid). This is a topic for another day.
Thank you all for the suggestions. My next step would be to check the AC gas as suggested by BHPian vividhavasthi.

Hi, Was the issue resolved for you.
I am still having the same issue in my Taigun. The service center have updated the AC software and refilled the gas but the issue is still there. The Compressor keeps cycling multiple times a min and when the compressor engages there is a jerk in the car. I have checked this on some other Taigun (from friends) and the issue is not there. But the test drive car in the service center is having it. So it seems some cars are having it and some are not.

Any idea to get it fixed?
Thanks in advance

[Nanolover]

Mordern cars in the interests of fuel efficiency, have the compressor cycling multiple times in small intervals causing these jerks to happen. Also the idling speed for new cars is lower in the interests of emission and FE, which leads to jerks when the compressor engages and the rpm drops, the ECU raises the engine speed to bring it back to idling RPM.

In BS3 or before, the idling speed was higher and the compressor load was factored in which doesn't lead to much drop in rpm upon compressor engaging.

I am afraid nothing much can be done other than to live with this.

[true_sedan]

Originally Posted by safedrive9

Hi, Was the issue resolved for you.
I am still having the same issue in my Taigun. The service center have updated the AC software and refilled the gas but the issue is still there. The Compressor keeps cycling multiple times a min and when the compressor engages there is a jerk in the car. I have checked this on some other Taigun (from friends) and the issue is not there. But the test drive car in the service center is having it. So it seems some cars are having it and some are not.

Any idea to get it fixed?
Thanks in advance

The jerk is still there albeit very less pronounced these days. I have to look for it to feel it. Maybe it was a mechanical thing that settled down with use. My advice would be be use the AC in auto mode which makes the interval between compressor ON and OFF longer. That way if it happens once every few minutes you wouldn't notice anything. Meanwhile let the car settle down mechanically.

Cheers!

[Jeroen]

Originally Posted by Nanolover

Mordern cars in the interests of fuel efficiency, have the compressor cycling multiple times in small intervals causing these jerks to happen.

Not sure I follow that. If anything the jerks depend on the type of compressor, with or without clutch. I understand these days a lot of variable compressors are equipped with a clutch as well. And the AC logic should actually clutch in without any gas volume being compressed. Only when the clutch is engaged should the variable compressor part start to compress.

For reference: I just took my wife's Ford Fiesta AC compressor apart:

https://www.team-bhp.com/forum/techn...ml#post5563686 (Anatomy of a Car AC Compressor (clutch/variable))

Originally Posted by Nanolover

Also the idling speed for new cars is lower in the interests of emission and FE, which leads to jerks when the compressor engages and the rpm drops, the ECU raises the engine speed to bring it back to idling RPM.

Do you have any examples and data to back that up? If I look at all my cars they all idle between 650-950 RPM when properly warmed up. Those are cars from 1982 till 2019. My older cars idle at lower RPM than my modern cars?! And they are all properly adjusted!

Originally Posted by Nanolover

In BS3 or before, the idling speed was higher and the compressor load was factored in which doesn't lead to much drop in rpm upon compressor engaging.

All these different standards are not my thing. But I thought one of the problems is that on these emission standards use of AC is excluded in the measurement.

Just for reference, I have seen some research papers and AC usage can push idle fuel consumption up by 90%! Not surprising. A typical AC compressor when fully loaded up uses 3-6 HP! And engine idling is (from a fuel consumption perspective) very similar.

Originally Posted by Nanolover

I am afraid nothing much can be done other than to live with this.

Correct. The one thing you can do is to ensure your AC system is well maintained. This means there should be sufficient refrigerant in the system and the condenser and evaporator need to be cleaned regularly.

[SathyaV]

Originally Posted by true_sedan

The jerk is still there albeit very less pronounced these days.

Hello, I own a Virtus GT MT 2024 model and I have the exact same issue. Mine had done only 2900 kms and being a manual, I can very well sense and feel the jerk especially when I'm downshifting to say 2nd or 3rd for an overtake.
Is the issue still there? and did you do any additional maintenance or repair works to sort it out? Would love to here your updates.

[true_sedan]

Originally Posted by SathyaV

Hello, I own a Virtus GT MT 2024 model and I have the exact same issue. Mine had done only 2900 kms and being a manual, I can very well sense and feel the jerk especially when I'm downshifting to say 2nd or 3rd for an overtake.
Is the issue still there? and did you do any additional maintenance or repair works to sort it out? Would love to here your updates.

It just happens to be the AC compressor kicking on and off that's causing the jerk. Overtime it should reduce once the mechanical parts settle. I have done 25k kilometres so far and the jerk is not noticeable anymore.