Volvo S70 has weird humming/buzzing noise when idling!

mikey4040 · Post by **mikey4040** » 31 Oct 2011, 15:15

Hi everybody,

I'm new to this forum and a new owner to a used 1998 Volvo S70 GLT automatic with 134,000 miles. Car runs real good and the previous took care of it with maintenance and repairs and such unfortunately today i noticed a weird buzzing/humming noise coming from the passenger side right around the thermostat housing area but i can't pinpoint the exact spot. It only makes the humming noise when the car is running and is in park. As soon as i take the car out of gear and place into any other the gear the noise stops. However when i drive the noise sometimes comes back for a couple seconds or so then goes away. When i stop though and put the car into park the noise comes back right away and is constantly. Anybody have a similar problem? Any suggestions? Forgot to mention car seems to performance normal however i did notice about 2 weeks ago the dummy temperature gauge seems to take a long time to reach the middle mark but previous owner did replace the thermostat at one point. Not sure if this is related maybe weak water pump i hope not??

I enclosed a picture where the noise seems to be coming from the general area. This is NOT my vehicle just a picture i found on the internet. Mine does not have oil over the engine like in the picture

-Thanks

Marcobrick · Post by **Marcobrick** » 02 Nov 2011, 03:13

I've had a timing belt idler bearing make a noise like you describe

Post by **Juan62** » 02 Nov 2011, 06:31

Just underneath your left hand, there is a auxilary tensioner...aka SERP Belt tensioner, check the two bolts (12mm top, and 13mm bottom) re-torque those two bolts to 15 lbs each. Start Car and touch the auxliary tensioner WITHOUT fingers/hands in the way of the spinning SERP BELT...be carefull. Should NOT be any noise. Also, make sure your front timing belt cover (black plastic) center bolt is secured (about 5" below the top of the cover.
Your Power Steering Pump; has the fluid been changed?

Post by **Fish stick88** » 02 Nov 2011, 11:04

Welcome to the forum, the best thing that you can do it upload a video of your car running, with the noise. it sounds like its not related to being in gear or not, im going to guess the difference in idle changes the vibrations on ___________ part.
Tensioner also my first guess.

lumberjackzac · Post by **lumberjackzac** » 02 Nov 2011, 20:05

harmonic balancer pulley - FTW

mikey4040 · Post by **mikey4040** » 02 Nov 2011, 23:50

Ok i just came on here today and reviewed your posts thanks. Before reading your thoughts I changed out the serpentine belt today with no change. I did check all the pulleys and they all seem quiet and tight. However the power steering pulley has a very very slight play to it and a slight quiet squeak to it when i spin it by hand. I did read on the web that someone witnessed the same on there power steering pump the squeak and the play and it actually was not even the problem in turned out to be the alternator so now I'm like wtf that's weird because it sounds like it's coming right from the top of the power steering pump and the guy that i read his post had a similar problem. Good idea! I will post a video tomorrow of the engine with the car at operating temperature making the noise so you guys can hear and see what you think. Thanks

P.S My temp gauge is now working fine it must of been the sudden cold weather we are having making it raise slowly. I also pulled the oil dip stick and took off the oil cap to see if any difference but no change as well. I checked the power steering fluid and it was a little below the cold mark when i checked it cold. I added some more ATF to bring it to the cold mark. Is it normal to get low? I think it must be either the tensioner pulley, Idler pulley, alternator or power steering pump at this point who knows that's why I'm here for help lol..

Post by **keepersboy** » 03 Nov 2011, 11:07

I had a noise like this on a 98 v70, Power steering fluid was low and foaming up a little, I changed the fluid by sucking it all out several times and addding new fluid. The noise went away, and the fluid quit foaming, I really don't know how this fixed it but it worked, I also could not get your youtube vids to play, It may just be me

mikey4040 · Post by **mikey4040** » 03 Nov 2011, 11:19

I took some videos of the noise today.

It should work if you copy and paste it in the web browser. I have it set up so people on here with the links above can see it thanks.

Post by **Fish stick88** » 03 Nov 2011, 11:59

how much fluid do you have?

mikey4040 · Post by **mikey4040** » 03 Nov 2011, 12:08

It was a little low the other day. I checked the fluid when the car was cold and it was a little below the cold mark. I added some ATF to the cold line and the noise didn't change still appears after warm up. It was not foaming or had any air bubbles and it was still red.

I was thinking about doing a simple drain and fill on the power steering pump tank. How should i go about doing this and how much ATF will i need i have a new quart in my shed is that enough for this? Instead of a turkey baster i have a plastic syringe with a little tube attached to it works great for jobs like this. I use this on my Lexus when i did the brakes to take fluid out of the tank so i can open the calipers. Can someone chime in on this and let me know what i should do. Do i do this with the engine cold or hot? running or off? How do i bleed the air or check for air in the tank? And how ATF do i need for a drain and fill on the just the tank? Thanks and great advice i like these forums i use the Lexus one to.