1999 C70 Whining Noise

Cammyron · Post by **Cammyron** » 17 Jul 2016, 05:03

Hi Guys,

First time posting here and first time Volvo owner. Have had Saabs before though, so that's kind of close right? We bought a 1999 C70 a year ago as a second car for when various parts of the family had to go two directions at the same time. Purchased with 184k kms on it and have put another 5k on it in the year we have had it. For the previous 100k kms it had been serviced (i have all the records) by a reputable independent here in Melbourne.

It has been flawless since we got it until the other day when it started making a horrible noise. Sounded like the typical bearing going on the idler pulley so i wasn't too concerned. Pulled the accessory belt of it today and the noise is still there. Listening to it without the accessory belt on and it sounds like it is coming from on top of the engine, just behind the exhaust cam. I guess it could be the tensioner pulley but they were only replaced 20k ago.

It also doesn;t have the symptoms of a PCV issue, no vacuum on oil filler/dipstick

I took a couple of vids if it helps. There are other vids on here and other sites but none of the ones that are still up sounded the same as this to me.

Idling with accessory belt off

Reving with accessory belt off

Thanks

Cam

Post by **abscate** » 17 Jul 2016, 05:23

It might be the Cam hub. I believe your 1999 has the adjustable exhaust hub (callled CVVT). Mine us growling a but now. If they screech, they are finished and you need to deal with it immediately

Towing it to shop would be prudent.

Failure will mean a new top end of the motor

Post by **Ozark Lee** » 17 Jul 2016, 05:38

Since you removed the serpentine belt and the noise is still there then it has to be in the timing belt path and that is scary.

There really is no camshaft bearing on the cars, the shaft rides in journals that are oil bathed. I don't hear lifter noise so the top of the motor isn't being starved of oil.

The suspects are the tensioner, idler, the CVVT hub, or even the water pump.

I wouldn't drive the car until you get it resolved. Even at idle if one of the bearings seizes it will bend valves. your car should have CVVT on the exhaust cam so you will need to do the preload procedure before removing the timing belt. Rotate the engine by hand clockwise until you get to the timing marks and then continue clockwise another 90 degrees. Rotate the engine back counterclockwise to the marks. At that point you can remove the timing belt and see which bearing is noisy.

When you put the belt back on you will need to adjust the outer sprocket on the exhaust cam to line up with the timing mark on the cover (12:00). Be sure to give the engine a couple of turns by hand and recheck the marks before you start the engine. It usually takes a few tries to get the tensioner properly set in the window.

...Lee

Cammyron · Post by **Cammyron** » 17 Jul 2016, 06:01

Ok, so first plan is to get the timing belt of and see how the tensioner, idler and water pump feel. How desperately important is it to have the cam lock tool to do that? like this https://s3.amazonaws.com/images.matthewsvolvosite.com/tim ... g-tool.jpg

This video seems pretty clear on how to take the timing belt off (its for a V70 but i am assuming its the same).

Also i have seen mention on a few post now about disconnecting the solenoid from the CVVT and see if noise reduces. Will that actually do anything if the bearings in the cam hub are shot?

Post by **Ozark Lee** » 17 Jul 2016, 09:12

The cam lock tool is particularly worthless with a CVVT engine. The video on removing the belt is appropriate for your car. You don't need to completely remove the belt to find the bad bearing. Just relax the tensioner and slip the belt off of the camshaft sprockets so that you can get it free from the rotating devices that the belt runs across.

The camshafts don't easily spin all on their own, you need to put some pressure on them to get them to move at all so if you just pay attention you will be fine. The outer sprocket on the CVVT does easily move and you need to line its mark up back to the 12:00 position as you slip the belt back on over it.

...Lee

Post by **abscate** » 17 Jul 2016, 11:47

You should be able to locate the screech with a piece of hose or Tygon (tm) tubing as a stethoscope.

On the timing belt area the noise will be ...

High - CVVT cam

Middle - tensioner

Low - water pump.

Cammyron · Post by **Cammyron** » 20 Jul 2016, 00:35

Firstly, thank you all for your help.

I finally got a chance (not dark, not raining and at home) to have a go with a piece of hose.

The noise is loudest at the idler pulley for the timing belt. The others all sound pretty quiet. Interestingly though the same noise can be heard by holding the hose above the belt between the two cam pulleys. Is this just noise transference or the sign of something else?

Post by **abscate** » 20 Jul 2016, 04:49

With a hose the noise will change as you move it around, nothing else wrong.

Cammyron · Post by **Cammyron** » 20 Jul 2016, 05:07

Cool. So just an idler pulley.

As I can't definitely say when the belt/water pump/tensioner were last replaced would you suggest it's worth doing them all as well? The service records I have mention a drive belt change but the part number us the one for the serpentine belt, not the timing belt

Post by **abscate** » 20 Jul 2016, 05:30

Cammyron wrote:Cool. So just an idler pulley.

As I can't definitely say when the belt/water pump/tensioner were last replaced would you suggest it's worth doing them all as well? The service records I have mention a drive belt change but the part number us the one for the serpentine belt, not the timing belt

Your service interval for the timing belt components ( belt, idler, tensioner) is 105k miles /10 years. You are overdue on time, although I wouldn't worry about that.

With the idler pulley screeching, it's a pretty easy conclusion the TB hasn't been done. There is also a sticker placed under the hood when it's done to document it.

Thanks the stars, stop driving it, and get the TB done!!

Good data point that miles/Kms are more meaningful than time on the impact of TB life..something I suspect is true.

I drove my 1999 to 221k km before changing it. Not recommended.