No start - buzzing sound in vacuum system

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.
1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70
User avatar
tom39
Posts: 124
Joined: Thu Oct 30, 2008 11:50 pm
Year and Model: S70 T5, 1998
Location: USA Virginia
Flag: United States of America

No start - buzzing sound in vacuum system

Postby tom39 » Mon Mar 20, 2017 9:19 pm

1998 S70 t5
So my car wouldn't start this morning and I ended up taking my truck to work. When I got home tried to diagnose the problem and the first thing I noticed was an actuator buzzing which appears to be part of the vacuum system. It is positioned directly in front the throttle cable wheel. The first picture shows a overview and the second picture is a closer view of it. My description would be that it is a silver tube actuator with a plug coming out the back end of it and vacuum tubes coming in and out of the front of it. Any way as any good mechanic would do (okay to be honest I am not a good mechanic) I tapped the end of it with a screwdriver to see if it was stuck. Then I unplugged it and plugged it back in. Afterwards the car fired right up. I'm thinking that something was stuck and tapping it unstuck it. I think this is the problem and the part is bad, the problem is that I don't really know what the part is called for me to try order one. Can someone identify the part of which I'm speaking?
20170320_163436.jpg
20170320_163432.jpg
98 - S70 T5 Silver 230k/mi
11 - S80 Silver 96k/mi

User avatar
misha
Posts: 3029
Joined: Sun Dec 07, 2008 11:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Flag: Serbia

Re: No start - buzzing sound in vacuum system

Postby misha » Mon Mar 20, 2017 9:27 pm

That's IAC valve and it's supposed to buzzz when key is in pos.II.
Don't need to replace it as long as it's working/buzzzing.
You can clean it with carb cleaner,instructions are in repair data base.
'97 850 2.5 20v /fully equipped/ Motronic 4.4 / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic/petrol+LPG
History of Volvos in the family:
'71 144 De luxe
'73 144 De luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

User avatar
tom39
Posts: 124
Joined: Thu Oct 30, 2008 11:50 pm
Year and Model: S70 T5, 1998
Location: USA Virginia
Flag: United States of America

Re: No start - buzzing sound in vacuum system

Postby tom39 » Mon Mar 20, 2017 10:46 pm

Would that valve sticking cause the car not to start? It was the only thing that I touched and the car started afterwards.
98 - S70 T5 Silver 230k/mi
11 - S80 Silver 96k/mi

User avatar
misha
Posts: 3029
Joined: Sun Dec 07, 2008 11:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Flag: Serbia

Re: No start - buzzing sound in vacuum system

Postby misha » Mon Mar 20, 2017 10:53 pm

Yes...sort of.
'97 850 2.5 20v /fully equipped/ Motronic 4.4 / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic/petrol+LPG
History of Volvos in the family:
'71 144 De luxe
'73 144 De luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

User avatar
AKJeeper
Posts: 49
Joined: Mon Sep 12, 2016 5:59 pm
Year and Model: 1996 850 Turbo Wagon
Location: Kodiak, AK
Flag: United States of America
Contact:

Re: No start - buzzing sound in vacuum system

Postby AKJeeper » Mon Mar 20, 2017 11:11 pm

The valve controls idle speed. If the valve got stuck, the car would have started if you put your foot on the throttle a little bit (like 1/8 or 1/4 throttle opening) while cranking. It probably could use a cleaning.


Return to “Volvo 850, S70, V70, C70 & V70-XC Forum (1992-2000)”

Who is online

Users browsing this forum: 98v70dad, ecbsykes, msmcrae and 16 guests

ViVA performance upgrades for Volvo cars