2006 XC70 AWD oil on bottom of Haldex

XC70NeverAgain · Post by **XC70NeverAgain** » 21 Jul 2024, 13:02

Hi Everyone.
I was backing out of my driveway this morning and heard a distinct whumping noise coming from the rear of the vehicle. I had assumed something was wrong with the parking brake shoes as I didn't get the same sound driving forward. Took the parking brake shoes out (one of the retainer springs was bad). Took it for a test drive and noticed there was still a whumping noise, but not nearly as bad as before. So I looked under the vehicle and saw the entire bottom surface of the Haldex area covered in oil. I know that shouldn't look like that, but I don't have the means today to repair it. If I drive the car to work and back (30 miles each way) am I going to do irreparable damage to this system, or is the damage done now?

Thanks in advance.

Post by **jonesg** » 21 Jul 2024, 13:49

pull the fuse in the rear cargo side panel for now.
no sense running the continuous pump dry.

XC70NeverAgain · Post by **XC70NeverAgain** » 21 Jul 2024, 13:56

That definitely makes sense. I will do that now. If the Haldex ran dry, would it be just the pump that would be bad?

XC70NeverAgain · Post by **XC70NeverAgain** » 21 Jul 2024, 15:55

I did what you suggested, removed the #23 fuse from the rear panel and took it for a drive. It started to make a noise similar to the noise a childs bike would make with playing cards clicking on the spokes of their rim. People were turning their heads to look at me so it must have been noisier than what I could here, lol. It also seemed like the car was dragging a bit trying to accelerate. Pulled over and put the fuse back in and all that went away. I may have to just drive it as it is till i can look at it better and get some parts ordered.

Post by **jonesg** » 21 Jul 2024, 21:08

that doesn't make sense, i removed my fuse yrs ago.
i pulled fuse 17. its 7.5 amp i recall.
if its running low on oil you can hear the pump whine.
haldex pumps run constantly, thats how the system reacts so fast.
a $12 stethoscope is super useful for locating noises.

either way, if you want to repair you have to find the leak, give a good cleaning with copious Brake kleener spray and paper towels, get it dry , take it for a spin and look for the leak. the o rings on the sensor/s in the DEM module would be my guess, but the pump and filter can leak too. they sell a reseal kit for the DEM.
Does the haldex function ?
does the prop shaft rotate in drive ? (lift all wheels).

plus, you don't actually know the source of the noise yet, its usually not the haldex.

getting the wheels off the ground and idling in drive is the easiest way i know to isolate the noise.
last time i had noise at the rear end it was a wheel bearing (drone noise ).

Chelpiszon · Post by **Chelpiszon** » 25 Aug 2024, 05:55

Today I had very similiar problem. My shaft spins, there are no faults but Haldex (mk 2 since its 2004 Volvo V70 awd) doesn't work. I think it might be low on oil. I pulled the fuse out yesterday and while driving today i had the warning light (usual thing while fuse is pulled out) but it was also making a weird noise as XC70neveragain described. While on gas it was kinda quiet but while coasting it was quite noisy. Put the fuse back in and it stopped.

Post by **jonesg** » 25 Aug 2024, 08:29

Chelpiszon wrote: ↑25 Aug 2024, 05:55 Today I had very similiar problem. My shaft spins, there are no faults but Haldex (mk 2 since its 2004 Volvo V70 awd) doesn't work. I think it might be low on oil. I pulled the fuse out yesterday and while driving today i had the warning light (usual thing while fuse is pulled out) but it was also making a weird noise as XC70neveragain described. While on gas it was kinda quiet but while coasting it was quite noisy. Put the fuse back in and it stopped.

maybe it isn't low on oil.