Passenger side engine mount bolts Topic is solved

iamhives · Post by **iamhives** » 25 Jul 2021, 12:51

Today I changed the passenger side motor mount on my 2006 V70. I'm trying to reduce a slight vibration at idle. Overall it was pretty easy. When I first got a glimpse of the mount I saw that the bolts into the engine weren't all the way in. At first it looked like they had been walking themselves out. However, when I came to reinstall the new mount I discovered that it was impossible to fully tighten up both bolts, almost as if they were both too long. I managed to get them a little tighter than the previous person who had obviously worked on them but I could only just about get the bottom one tight but the top one seemed to be 3-4mm away from being tight against the mount. Is this something others have experienced. Should they be able to fully tighten against the mount. Maybe my bolts are too long? Are both bolts the same length?. Mine were and its almost as if the top one is supposed to be shorter. Any insights welcomed.

Post by **cn90** » 25 Jul 2021, 14:27

- Any broken studs inside the holes?
- The current bolts: are they factory Volvo bolts or some hardware store bolts?

iamhives · Post by **iamhives** » 25 Jul 2021, 15:53

I didn't see any broken studs in there and they looked like Volvo bolts (although I didn't look at them very closely). Have been looking on parts diagrams and seems that the part number appears to be 982819 which is M10/40. Since I've put the car back together I don't have the bolts to measure but that seems about right for the ones that are on there. By coincidence I have a pair of 982817 bolts (which are M10/30) in my parts box. Not sure why I have them but they're spares maybe from suspension work. Seems like that 10mm would allow the bolts to be tightened fully against the mount. There would probably be 5mm less threaded contact. I may try installing those instead unless someone tells me that wouldn't be a wise move.

Ironically the mount I changed wasn't in terrible condition so all of this may not be the fix for the slight idle vibration that I'd hoped.

Post by **cn90** » 25 Jul 2021, 21:13

Or you can take ONLY 1 bolt out at a time and measure it.
Post some photos of the current problems when you have time...

iamhives · Post by **iamhives** » 25 Jul 2021, 22:04

That's probably what I'll do (so I don't have to mess with lifting the engine etc again) starting with the top one which is one that's furthest from being full screwed in. Only problem is it's forecast to be in the 90s this week so may wait for a cooler day. Attached is a picture of the bolts as I found them before replacing the mount (looks similar after)

iamhives · Post by **iamhives** » 26 Jul 2021, 10:17

While looking for torque values for other fasteners I found a list that had this bolt listed as an M10/35. Is this one of those parts that varies based on VIN number and if so what is the most reliable source for part numbers/diagrams that differ by VIN number?

darylrobert · Post by **darylrobert** » 28 Jul 2021, 07:20

they should be tight, someone has put incorrect length bolts on there. Check you upper torque mount thats where 99% of failures are. Do not get the poly mounts they are horrible

iamhives · Post by **iamhives** » 31 Jul 2021, 22:12

I've already replaced the upper mount with little/no change. I also changed the lower torque mount and didn't notice much difference with that either - maybe slightly firmer shifts. Only mounts left are the two lower ones. They don't look too bad. I have replacements but will probably wait for the weather to cool down.

Meanwhile I will try and replace the bolts on the lower passenger mount with shorter ones since I do now think someone must have used ones that are too long.

leapdragon · Post by **leapdragon** » 01 Aug 2021, 11:02

I just did this today. Mine are definitely 100% tight against the surface of the mount when tightened to the block per VIDA torque spec.

In my case I'm worried about the frame bolts. I couldn't fit any of my torque wrenches into that space and I wasn't about to take the axle out just to replace the mount, so I just used a breaker bar and tightened to "good and tight but yikes don't break it."

But I'm gonna have to check here and there to make sure they're not walking out, it took a LOT of torque to get them loosened.

iamhives · Post by **iamhives** » 09 Aug 2021, 13:57

Over the weekend I went back in to adjusted what I had. After some more thorough research I found that my car (2006 V70 NA FWD) calls for different sized bolts M10/35 (top) and M10/40 (bottom). Seems that there are several slightly different configurations for these bolts/mounts depending on engine, FWD vs AWD, VIN # etc so whoever worked on the car previously must have changed the bolts and looked up the wrong part number for the car. My car had M10/40 in both hence the inability to tighten up the top one. I had M10/30 on hand but they are too short so I cut down the existing M10/40 to about M10/35. Now I can tighten both down fully.