I’m looking for technical help or recommendations on:
Commuting today I noticed a rotational grinding sound coming from (I think) behind me. I was driving at about 40mph in motorway traffic, very low revs, no acceleration. As I slowed, the sound repetition also slowed too, whether the clutch was pressed or not didn’t matter - only low revs/no acceleration. Once I pressed the throttle the sound goes away, but once the throttle is lifted (e.g. changing gear) or the acceleration is reduced in any way the sound comes back.
When slowing for a red light I can more clearly hear the sound as it sounds like metal is slowly being dragged across metal.
I will try to get an audio recording uploaded when I can.
I’ve heard people say that it can be the propshaft rubbing (and accelerating makes the noise go away due to the pitch of the car changing) but this could only happen if something had become damaged or bent and this hasn’t been the case and it quite suddenly appeared half way on my commute.
I will take a look under the car after work and get an audio recording of the sound but in the meantime if anyone has experience with an issue like this then I’d be happy to hear your thoughts! Thanks
I’ve noticed with mine that I get terrible road noise from behind the seats when the roof is up.
I rarely drive with the roof up so it doesn’t concern me.
I figured out (not long after purchase), that the noise comes from the tyres as different road surfaces produce a different sound.
Here’s an audio recording of me gently slowing down for a red light. Beware trecording is quite quiet but I pull the handbrake up at the end which is quite loud!
Something else to consider. The brake pads should have a wear indicator tang.
When the pads wear down, this tang will rub on the disk which gives an audible indication that the pads are getting ready.
Generally this would be a squeal, but could manifest as a grinding noise as it’s metal on metal.
Get it up in the air and start spinning the wheels, see if anything comes to light.
If you can get it secure, ie on blocks and wood then maybe get the back end up and drive it.
It does sound like a rotational sound, as said above rear wheels off the ground and rotate them by hand. Could be brake related, you’ll find out I guess with that simple check first.
Try gently applying the hand brake as you are driving and see if the noise changes.
I would then get the car in the air and check the ‘brakes’. Heat, pad thickness, rubbing on back plate etc.
Next the prop shaft for play and rubbing.
Then do a ‘spanner check’ on all mounting bolts for everything.
Finally are the diff and/or gear box full of oil. There is a filler/level ‘hole’.
Don’t discount that the noise could be coming from the front so check there as well as at the rear.
Something caught between one of the backing plates and the discs? Used to get this a lot on my old car as there was very little clearance, was a very similar sound but more high pitched when it was a pebble.
Just been to check the car over during lunch at work.
The good news is that there will be no repair bill.
The bad/terrifying news is that the reason for the noise was that all of the wheel nuts on the rear right were loose, literally finger tight.
I’m trying to think back to when I last took the wheels off as there’s no way all the nuts could become loose at the same time naturally. That must’ve been at least a few months ago though.
So, all safe for now but I’ve learned a lesson in checking things over once in a while.
Something as simple but potentially dangerous too.
I had similar a few years ago, I didn’t remove the wheels but trusted someone else, to put them back on properly too.
Is there any way to check the rear pads without lifting the car/taking off the wheels?
I’m on the point of booking a free brake check somewhere, but I’m likely to get told I need new rear discs and pads and, quelle surprise, there’s a premium applied.
Then I’ll come over all English and pay the premium, because weren’t they a lovely bunch and, gosh darn it, they did check them for free.
I’d much rather show SWMBO that I’m saving money on that premium by buying my own jack, stands and tools, but I need to confirm I actually need all that stuff in the first place.
A proper brake check I would consider being taking the wheels off to check the rear most pad and disc condition, you can’t see them at all wheel on. Yes you can see the pad/disc condition through the wheel, just that outer facing set.
Now I know what you mean about being told your discs are either shot or don’t need replacing. I had a bad experience a few years ago, a quick look at the outer facing pad/discs told the mechanic (who I found out later was learning) they looked ok. They weren’t on the rear faces though, they were in a shocking condition.
I check my own brakes now.
So get those tools in use, brake service work isn’t a bad job just discs and pads to replace easy enough. It’s when you have sticking slide pins and calipers it becomes more involved but regular servicing should minimise that risk.
