Groan/Humming at 1500RPM

johnrapier · Post by **johnrapier** » 09 Jul 2016, 20:22

Good Evening,

Recently I have noticed that when my 01 Volvo V70 2.3 T5 is in Drive between 1200-1600RPM there is a is a low pitched groan but once I pass 2000 RPM completely gone. I have done the following.

1.When car is in Park and I rev to 1500 sound is not present
2.If I put the car in Drive and hold down the brake so nothing is moving at 1500 RPM I get the sound
3.I have replaced the CX axle and wheel bearings
4.If I'm driving at around 35-45 mph the sound is constant
5.There is no smoke or oil leak that can be found by two different independent mechanics
6.No CEL lights are registering
7.Oil has been changed with high mileage synthetic blend every 5000 miles
8.Car has 280,000 miles on it
9.Transmission was replaced with reman from Volvo by Volvo dealer at about 210,000 miles
10.Some oddities which I do not think are related, when I press on the brake pedal while in Drive the car start to vibrate all mounts have been replaced within the last 10000 miles, once I take my foot off the brake pedal vibration goes away (brand new brake booster and master cylinder 30000 miles ago)
11. Serpentine belt, and tensioner replaced 5000 miles ago
12. ETM has been replaced
13.Muffler and straight piped replaced within 1500 miles ago
14. One other thing to note when car is in park and I rev the engine when the engine is slowing down I get a whirling sound from what sound like under the timing belt cover, any thoughts. Timing belt kit replaced at 205,000 miles

Could this be nothing more than a vacuum leak or turbo or something less apparent.

Thank you in advance on any suggestions.

Regards,

John Rapier

Post by **MadeInJapan** » 10 Jul 2016, 00:59

That's a tough one...we put the strut brace stiffening pieces in to make the piece that holds the upper engine torque mount in place a solid piece a few years ago and so get a groaning sound right at 3000 rpm, but that's it and we know what that is...maybe less groaning and more just the sound and feel of vibration though (this is on our '04 V70). What you describe to me seems more axle related or it could be transmission related and the vibrations from braking sound more like the axle and so the two problems described could have their roots in the same issue. ...or on second thought, it could be a bushing going bad in your control arm. This could cause the brake vibrations...but a bad axle could cause that too, esp. when in Drive, hitting the brakes. Have you had either control arm (left or right) replaced? Also, have you flushed or done a drain and fill of the transmission fluid anytime on your car since it was installed?

At this point, we are just brainstorming so let's not go off throwing more $$ at this car until you have a clear direction to what is truly wrong with it. That said, congrats on 280K miles!! I do not believe what you have is a vacuum leak or turbo related...an engine when slowing down would not impact the turbo either- I think you can rule either or these things out... Do not have a clue about the whirling sound. Brake vibration could also be from a warped rotor or rotors or hot spots on the rotor from the pads.... Sorry my response was all over the place...

Post by **abscate** » 10 Jul 2016, 03:40

Point 2 is telling you it's transmission related or engine/load related ( really esoteric)

Nice diagnostic Data collection!

johnrapier · Post by **johnrapier** » 10 Jul 2016, 10:20

Control arms also replaced
The vibration from pressing brake is only when car is not moving but in drive release brake pdeal car vibrArion goes away

One things that has not gotten any love lately is the pcv system and thtotter body

Post by **vtl** » 10 Jul 2016, 19:34

Did you use anything with word "poly" in it when replacing mounts and torque rods?

johnrapier · Post by **johnrapier** » 10 Jul 2016, 21:37

no poly bushings, newest thing i notice burning oil smell coming from right side of the car smelt it when i was picking up bags from front passenger leg area

Post by **oragex** » 11 Jul 2016, 05:32

Which brands are the parts that have been replaced?

johnrapier · Post by **johnrapier** » 11 Jul 2016, 17:26

Mounts Hutchison
Wheel bearings moog
cx avle genuine volvo
transmission reman volvo
everything else genuine volvo

Post by **vtl** » 11 Jul 2016, 20:56

Remove the crank pulleys cover and check VVT hub(s) play when the engine is running. Should not be any visible.

Post by **abscate** » 12 Jul 2016, 05:00

I think I would try a series of transmission drain and fills ( drain pan, replace same amount with fresh ATF. )

It's definitely engine or transmission related based on your test 2.