www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW MKIV-A4 TDIs (VE and PD)

VW MKIV-A4 TDIs (VE and PD) This is a general discussion about A4/MkIV Jetta (99.5-~2005), Golf(99.5-2006), and New Beetle(98-2006). Both VE and PD engines are covered here.

Reply
 
Thread Tools
Old June 29th, 2017, 06:08   #1
vwnathan
Member
 
Join Date: Jul 2014
Location: Cape Cod
TDI(s): Mk4 tdi
Fuel Economy: 42
Default AC compressor knock at idle

So for the longest time, whenever I have the AC on and after driving a bit the compressor will knock only at idle. Give it a little throttle and it stops, let off and it's back. All fasteners are tight and the pulley nut is tight. Lines looked like they are routed fine. If I put my hand on the compressor while it's knocking, I don't really feel the knock. This is telling me that maybe the clutch is failing or has play in it when engaged?

I searched the forums and didn't really find anyone else with the same issue. Was just curious before I buy a new clutch and pulley assembly.

Other than the noise, the AC works awesome! I did read that and overcharge could cause the compressor to make noise, so I evacuated and recharged but still there. Also vacuumed the system and re-oiled the compressor.
vwnathan is offline   Reply With Quote
Old June 29th, 2017, 07:36   #2
compu_85
Gadget Guy
 
compu_85's Avatar
 
Join Date: Sep 2003
Location: Springfield VA
Default

It could be the compressor is getting worn out.

When the car is idling with the AC on how does the belt tensioner look? It shouldn't move around much.

-J
__________________
Present:
2013 Fiat 500e. 18,000 miles. Almost 100 miles per charge!
2012 Passat SE TDI DSG. 112,000 miles. Factory Alarm, LED tails, Memory Seat, HIDs 38/48 MPG. Buy it from us!
2004 Touareg V10 TDI. 165,000 miles.
99.5 Jetta "GLX" TDI. 310,000 miles. Half way there!!! Power Memory Seats, HIDs 11mm pump, BV39 Turbo, RCIII 36/47 MPG.
1991 Mercedes 350SDL 230,000 miles, 70,000 on engine. 18/27 MPG.
Past:
1988 Audi 5000S Quattro, 1992 Jetta ECOdiesel, 1991 Jetta ECOdiesel.

Check out the official TDIClub Chat Room!
Quote:
Originally Posted by BRUSSELS BELGIAN View Post
Maybe I should pay MYSELF to do bad work on my car!
compu_85 is offline   Reply With Quote
Old June 29th, 2017, 20:49   #3
csstevej
Veteran Member
Default

How is your alt pulley?
It might be locking up and releasing at idle giving you that noise.
__________________
2001 golf auto to 5 speed manual swap,G60/VR6 clutch setup,coolant migration mod.
csstevej is offline   Reply With Quote
Old June 30th, 2017, 06:28   #4
Genesis
Veteran Member
 
Join Date: Feb 2003
Location: Niceville, FL
Fuel Economy: 53/48/42
Default

What Steve said.

Make sure you're looking at the right thing....
Genesis is offline   Reply With Quote
Old June 30th, 2017, 11:39   #5
vwnathan
Member
 
Join Date: Jul 2014
Location: Cape Cod
TDI(s): Mk4 tdi
Fuel Economy: 42
Default

Quote:
Originally Posted by compu_85 View Post
It could be the compressor is getting worn out.

When the car is idling with the AC on how does the belt tensioner look? It shouldn't move around much.

-J
AC off or on, it bounces a little bit but not too much.

Quote:
Originally Posted by csstevej View Post
How is your alt pulley?
It might be locking up and releasing at idle giving you that noise.
Quote:
Originally Posted by Genesis View Post
What Steve said.

Make sure you're looking at the right thing....
I'm positive it's not the alternator pulley. Its new INA along with a reman alternator. But I have taken the belt off and verified its working correctly
vwnathan is offline   Reply With Quote
Old August 13th, 2017, 11:31   #6
vwnathan
Member
 
Join Date: Jul 2014
Location: Cape Cod
TDI(s): Mk4 tdi
Fuel Economy: 42
Default

New compressor and knock is completely gone.
vwnathan is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Is my AC compressor bearing bad? Makes noise when AC is off, goes away when AC on. vtx531 VW MKIV-A4 TDIs (VE and PD) 4 May 30th, 2016 18:51
Question....Will an AC clutch from a gasser fit a TDI AC compressor phawkins224 TDI 101 6 April 21st, 2016 06:44
2 years post rebuild my AC compressor died(bearings), How about electric compressor? josh8loop VW MKIV-A4 TDIs (VE and PD) 6 January 9th, 2012 19:54
WTB MkIV AC Compressor clutch or trashed ac compressor (with good clutch) Ironforger Private TDI Items for Sale/Wanted 0 December 1st, 2007 18:24
AC compressor noise at idle. Cracker VW MKIV-A4 TDIs (VE and PD) 2 February 8th, 2004 18:43


All times are GMT -7. The time now is 17:36.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.13682 seconds with 13 queries
[Output: 76.69 Kb. compressed to 67.53 Kb. by saving 9.16 Kb. (11.94%)]