Volvo S70 has weird humming/buzzing noise when idling!

[mikey4040]

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.

[Fish stick88]

""Power steering fluid


The dipstick has marks for checking hot and cold oil. The oil level when the engine is cold must never be higher than the COLD

mark. After the engine has reached normal operating temperature, the level may not be higher than the HOT mark. Top up when the level is at the ADD mark.
Check the level at every service.
Fluid type: ATF
Replace: no fluid change required.

Brake and clutch systems

The brake and clutch systems share the same fluid reservoir. The fluid level should be between the MIN and MAX marks.

Fluid type: DOT 4+
Replace: Every second year or 30,000 miles (48,000 km). The fluid should be replaced once a year or every 15,000 miles (25,000 km) when driving under extremely hard conditions (mountain driving, etc.)

Check, without removing the cap, that the level is above the " MIN " mark of the fluid reservoir.
Always entrust brake/clutch fluid changing to an authorized Volvo retailer.""

This is what volvo recommends. Try doing a simple test, in park, while the engine is idling, turn your wheels quickly, Any drop on RPM's?
I wouldn't recommend changing to synthetic, has a lot of bad reviews online, developing leaks and such.
Otherwise, http://volvoforums.com/forum/volvo-xc90 ... how-55014/
Fairly good write up. I would try that before i did something to extensive, also, if you hold something against the pump (figuring it is making the noise) you should be able to either change the pitch, or experience vibrations off it.
Let us know what you get,
AJ

[Billc1015]

It sounds to me like it could be eiter the idler pulley, tensioner pulley, or maybe the alternator. Try listening with a stethescope (or long screwdriver) on each part and see if you can isolate where the noise is coming from. Also see if the noise changes when the headlights are turned on and off. If so it could indicate a problem inside your alternator. I have seen alternators that spin smooth by hand but make some pretty funny noises when they are charging.


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[mikey4040]

Earlier today when i was standing there trying to listen real carefully(kinda hard when you have literally a busy road right next to your house lol) i could of swore it sounded like the alternator for a couple of seconds when i hovered my ear above the back area of the alternator. Still hard to tell. I think tomorrow morning I am going out and picking up a stethoscope at walmart and then returning it when I'm done with it before i start buying parts or doing any unnecessary work.



Something i thought of today when i first started to hear the noise a few days ago. It started to make the noise after i parked the car at my parents house put it in park and after i pulled the e-brake. I never used the e-brake in a long time i only used at my parents house because their driveway is a hill. Would the e-brake have something to do with the noise or was it just a coincidence it happened at that time? I'm just trying to back track what i did since i started hearing the noise.

[Billc1015]

The e-brake has nothing to do with the engine. It is a cable opperated drum style brake located on the inside of the rear brake rotors. The only things that happen when you use the e-brake is the rear wheels get locked and the "BRAKE" light in the instrument cluster comes on.

[mikey4040]

Yeah i did not think it had anything to do with the e-brake it was just a stupid thought. I did the drain and re-fill with a turkey baster to the power steering pump reservoir a few times nothing change noise still present. I checked the 2 bolts on the tensioner pulley seems tight. I ended up starting the car and trying to listen with a large screwdriver i heard noise on every component i tried it on(alternator,power steering pump and tensioner pulley) the other components were out my screwdrivers reach to safely do it so isolating the noise is hard with a screwdriver. Question the tensioner pulley is it suppose to be quiet when you put a screwdriver to it i can hear noise internal sounds like a grinding noise as it's spinning but the pump kind of sounded like that to.

[Fish stick88]

Stethoscope for dummies (screwdriver, head down, butt of it in your ear) works just as good. Doubtful of the E-brake, if it were hung up you wouldnt be going anywhere, if anything, try pulling it and letting it down a few times.

[mikey4040]

I did the screwdriver trick exactly how you mentioned and i did it in different spots on each component as well. Kinda of hard to pinpoint it. I'm going to post on another Volvo forum to see if anyone on there had a similar problem.

[rspi]

I didn't think a recording would help us but the sound is horendas. I was expecting a buzz, that was more like a howling growl. What you should do is take the serpentine belt off and start the car (belt can be removed in seconds). If the noise is still present, the problem is in the timing belt path. If the noise goes away, it's in the serpentine belt path.

Now, if the problem is in the serpentine path, no real big deal. If it's in the timing belt path, dial 911. Get it fixed like - TODAY. It's likely a bearing on one of your rollers about to totally fail and toss your timing belt, which will pretty much destroy your motor. You may want to find out when the last time the timing belt was replaced with idler and tensioner roller.

Other than that, congrats on getting a very nice model car. Very good car to own.

[Ozark Lee]

+1 on what rspi said.

The dash will light up like a Christmas tree without the alternator running but it won't hurt anything.

...Lee