Could it be the clutch engaging on the a/c compressor? you should be able to tell by switching the a/c on and off - the clutch engages on my car 0.5 - 1 sec after turning it on.

Cheers,

Alex

 

I've noticed, with A/C on, it sounds sometimes like the blow-off valve is letting part of the turbo pressure pressure out prematurely. Just like your "tchup!" sound... sharper and shorter than normal blof-off valve sound.

This has happened quite rarely, when accelerating with low/med boost... but I'm still wondering about it.

-Fernis

 

Hi All

Since using my aircon at the 'ring earlier this year, I've got the following problem;

With aircon on, and at low revs/boost, I get a "tchup!" sound (which sounds a bit like a misfire and can be felt like a hiccup through the go pedal) intermittently - it's most likely to happen when I lift off the gas, but also occurs sometimes on gas.

Knocklink doesn't light up and with full bore take-off's everything is OK (I think aircon stops after .7 bar?).

Could it be the compressor? In normal operation it's not overly noisy.

I'm going to get the dealer to look at it, but wondered if anyone's had similar?

Thanks
Richard

 

Could it be a loose aircon belt? I had the same problem before.

Cheers!

 

Thanks - I'll check the belt.

It doesn't feel like this though - the "tchup" sound is accompanied by a slight hiccup in the engine.......

Alex - it does it all the time, maybe once or twice a minute. And not just with transitions to high/low boost - most annoying/frequent occurence is off boost town driving.

Cheers
Richard