Julian
Hi guys,
My first technical post on the forum!
Since buying my 1996 850R wagon at the start of the year, it has had what I would describe as a rattle/vibration that is present when the engine is under load at low rpm. For example, if I drive up a steep hill in 3rd gear (manual gearbox) it will make this vibration/rattle, whereas if I shifted down to second to make the engine produce power at higher RPM it would go away or become less pronounced. Unless I'm imagining it, I think I can feel a slight vibration/rattle through the floor/pedals when this noise happens.
I have checked the following things, which I don't believe are causing it:
- Upper engine mount (from head to firewall), and engine mount beneath crank pulley on right of car. I replaced both anyway and didn't solve the problem
- I checked the heat shields on both the exhaust manifold/turbo area and the long one that runs above the exhaust pipe and cat converter under the car. The manifold/turbo one was super tight, and I tightened those strange rubber/plastic nuts that hold the shield above the pipe/cat as much as I could. I also put small rubber O-rings between the shield and body where each screw goes through in case that was the cause of vibration
- I don't believe it is engine knocking as I only ever use 98 octane fuel, and it happens even under little or no boost
If I turn hard right, I get the click-click-click of a worn CV joint, so perhaps this could also be the cause of the sound under load? Other than that the only unusual thing the car does is a sort of rubbing/squealing sound when I release the clutch when the car is in gear to start moving sometimes. This happens much more when cold, and mainly when taking off from a standstill (although a small chirp/squeal is sometimes noticeable when I shift from first into second and release the clutch when cold). This sound only happens when I release the clutch with it in gear, there is no excess clutch thrust bearing sound that I can hear when I just depress/release the clutch in neutral. Anyhow, this sound may be completely unrelated to the rattle/vibration this thread is about.
So any ideas if a worn cv/drive axle could be the problem? or are there any other causes of sounds like this?
Any advice would be great
Ex850R
Needs new clutch?
As well as driveshaft/s.
Di you do the upper engine mount at the firewall itself? ( 2 bushes there )
Nice R , love the white!
Julian
Thanks for the response.
I only replaced the one at the cylinder head side- the other one seemed to look ok. Also, the two small bushes on the transmission support arm seem to look ok, but I have only looked at them with them in the car and haven't removed them to check. They don't appear to have excessive play though.
When you say "needs a new clutch", do you mean the friction material might just be worn out? I kind of thought that it might be ok, since it doesn't slip at all, but I'm no expert so it might be the case.
Are worn CVs known to cause this rattle/vibration even when not turning? I know I should replace the clicking one anyway though. If it happens when I am turning hard right, do you know if that indicates a CV joint on the left hand side being worn?
Ex850R
If you take out the top engine bracket from the firewall you can see rubber bushes WILL be toast.
The lower gearbox bracket will probably be toast too , its an old car...its to be expected.
You have an engine mount on the steering rack too ( yes , on the rack itself , crazy...) it may need done.
You can get poly bushes for the firewall , lower gearbox ( both) and many other spots too.
I have a V70T5 with the LWR gearbox , upper engine mount bushes in poly and it gives a nice buzz and sound of the 5 cylinders doin their thing! ( also new firewall bushes , Volvo STD ones in rubber)
@AshDVS can help with poly type bushes an many other parts including a front 320mm dia and bigger caliper brake package!
Maybe the clutch needs diagnosed , whats the pedal travel / pickup like?
Have the CVs checked /reco driveshafts maybe.
Julian
Ok, I'll check and maybe replace the firewall and gearbox mounts. I put a polyurethane mount in the top one that I did replace. I haven't checked the steering rack mount.
Pedal travel for the clutch feels normal. I find the clutch to grip quite quickly, not gradually and progressively as it does in many cars, but thought that might just have been an 850 thing. I'll check the book I got from the previous owner to see if they ever changed the clutch plate, as they kept receipts for all parts they bought.
Is there an easy way of checking cv joints without taking them out of car? I jacked up each side of the car the other night and rotated the wheels by hand at full lock, they were stiff to turn but no grinding or play, but I guess this wouldn't be noticeable at low speed and not under load anyway. I'm thinking maybe just one cv is worn since it only clicks turning right.
94_850_t5
For what it's worth, my guess would be one of the driveshafts. Yep, one in poor condition can certainly cause the described effect.
Julian
Ok, thanks for the advice. What is the best way to determine which driveshaft is worn? None of.the boots look split but clicking occurs when turning hard right
Ghettobird
Full lock in reverse L/R
The clicky side will be the stuffed one
nickm
Clicking CV joints could also give you vibration. Sort them out first as when they fail you go nowhere.
jamesinc
I've had CV joints in my 850R vibrate under load, and stop vibrating when you back off.
Julian
Yeah, that's what is happening to mine. I'm thinking I may need to replace them, I've heard that doing whole driveshafts is easier than just the cv joints?
Ghettobird
They are 1 part of the whole thing
you have to do the shafts to do the joints
Ex850R
Reco ones?
nickm
New ones here I'm using them. About 250 a pair I think
anfdriveshafts.com/
nickm
You need a 36mm socket to do this the rest is a simple job
Julian
Hey guys, in search of this rattle/vibration I have now:
-replaced top torque mount (one against firewall is fine), one of the gearbox mounts (other is fine), mount under the pulleys. Hydraulic mounts seem ok (no noticeable leaks or cracks when I jack up slightly)
- had driveshafts rebuilt
- turbo back exhaust (not specifically targeting the rattle but does eliminate exhaust as a candidate)
- put rubber spacers between heat shield under car and car body where it mounts
- replaced sway bar end links
- Been under car many times shaking/tapping everything I can see to try to tell if it could be causing the rattle/vibration.
- if I push clutch slightly to load clutch thrust bearing it still makes the rattle.
It's really annoying and I'm not sure what else to target.
Is there anyone around Newcastle who has experience with 850s who thinks they'd be able to diagnose this sound if I met up with them and took them for a quick drive? It'd be awesome if someone knew in a second what was wrong with it.
Cheers
94_850_t5
Did you ever try changing gearbox oil...maybe go to an 85w140 gear oil to see if any difference.
Cheers
Julian
Yeah I put fresh oil in when I changed Driveshafts and it didn't change it at all. That said, the stuff that came out still looked super clear so I don't think it really needed the change anyway.
94_850_t5
Does the issue vary depending on temperature. ie when the car is cold vs warmed up.
Julian
No it's the same all the time