IPD sale XeMODeX - Experts in Volvo Electronics
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

98 S70 Engine ‘singing’ noise [broken vaccum hose at air cleaner box] Topic is solved

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

Stu70
Posts: 34
Joined: Wed Oct 12, 2016 10:27 am
Year and Model: 1998 S70 10v
Location: New Zealand
Has thanked: 11 times
Been thanked: 2 times
New Zealand
Stu70

98 S70 Engine ‘singing’ noise [broken vaccum hose at air cleaner box]  Topic is solved

Post by Stu70 » Fri Jul 05, 2019 6:22 pm

Hello, I’m hoping someone can shed some light on my troubles...
B5252 10v , once car gets to operating temp to begins to “sing” I’m devaluing Volvo’s when I pull up to lights- it’s a ‘oh he should get that noise fixed’ sort of noise - see video
PCV done 35k miles ago. Noise started before I did timing belt, pump and tensioners, and keeps going when serp belt off , but stops when engine revved -see video.
Using an electronic stethoscope, it seems to be coming from block or PCV tank. Louder down the gap between 2-3 intakes on the manifold.
Any thoughts ? getting parts from across the world does make it expensive to ‘shotgun service’- just replace everything it might be and never knowing what it was that cured it.
I’m wondering if a partially blocked hose might set up a resonance? Or a hole in the intake gasket/ manifold might whistle?

Video here...


Many thanks


1998 S70 10v BiFuel “it’s a what??”

User avatar
abscate
MVS Moderator
Posts: 18155
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 194 times
Been thanked: 646 times
Trinidad & Tobago
abscate

Re: 98 S70 Engine ‘singing’ noise

Post by abscate » Sat Jul 06, 2019 4:01 am

That sounds like a vacuum leak, I would pull the intake and check the Pcv system for a loose or holed hose
These users thanked the author abscate for the post:
Stu70


Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW

Stu70
Posts: 34
Joined: Wed Oct 12, 2016 10:27 am
Year and Model: 1998 S70 10v
Location: New Zealand
Has thanked: 11 times
Been thanked: 2 times
New Zealand
Stu70

Re: 98 S70 Engine ‘singing’ noise

Post by Stu70 » Sat Aug 03, 2019 12:34 am

During reassembly of the inlet manifold not really finding any thing out of order. Last thing to connect were the hard hoses on the back of the air box , putting more pressure on the hoses than when I tested them with a tug. I found the top hose that goes to the hot air bypass flap had cracked and was just holding on by a thread, right down low on top of the vacuum damper.
That would explain the high pitched whine and it only happening when the car was warmed up.
Thanks Abscate for your reply, and your thread on tactile vacuum hose checks. Had I throughly tugged and looked properly even right down there I could have saved a few hours and few dollars...


1998 S70 10v BiFuel “it’s a what??”

User avatar
abscate
MVS Moderator
Posts: 18155
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 194 times
Been thanked: 646 times
Trinidad & Tobago
abscate

Re: 98 S70 Engine ‘singing’ noise

Post by abscate » Sat Aug 03, 2019 6:53 am

Stu, thanks from the follow report from NZ!


Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW

Post Reply