Now then folks, I hope somebody can help solve my problem with an annoying rattle I have.
Car is a 2010 MK3.5 with BC racing coilovers and has been lowered accordingly.
I have an annoying rattle/rumble coming from behind me and more to the rear nearside of the car. It happens when I Â am driving slowly off my driveway on a block paved road and similar rough surfaces.
It only happens when the soft top is raised. When I put the roof down there is nothing- weird.
Before I discovered the link with the rumble and the roof I tried all the usual suspects and did the following:-
Replaced rear droplinks and rear ARB bushes. Also checked everything was tight. Also checked the bumpstops inside the coilovers. Taken everything, jack etc out of the boot. Everything checks out.
When I realised it may be roof related I then went on to remove all the interior plastic behind the seats and stuck bits of foam where it looked like something may rattle.Â
Garage can’t find anything, MOT man said all good underneath.
It is driving me mad.
Can anybody think of anything I’ve missed please
You’ll hear more noise with the hood up because they add a degree of soundproofing when folded. Also any interior sound is drowned by the exhaust and other outside noise. Â
Last year mine was making a horrible noise with the hood up. I tried all sorts to find out where it was coming from and even went as far as soundproofing the whole boot, the floor and huge plastic panel behind the seats. Although much better the noise was still there. Came the time when the disc pads needed replacing and I soon found the cause…the insides of both discs were shot and the caliper sliders bone dry and rusty.
Could I suggest it could be the baffle in the lower part of the roof drain NS. If the baffle is open or dislodged it will be letting road noise into the cabin that side, the reason for the baffle is just so, to omit road noise/dirt being thrown into the tube but allow rain water drain off from the roof. Of course roof down the noise wouldn’t be apparent.
Of course it could still be the wheel bearing but check the tube first, you can google pics Mazda NC roof drains for instance (images) to give you an idea. The tube baffle can get dislodged if cleaning the drain tubes and withdrawing the cleaning rod (trombone brush) back up the tube, it should go one way, down from the top and withdrawn from below, never poke it up from below
Cheers for your thoughts guys. I’ll look into both ideas.
The noise is more of rumble and much worse on the block paving. It rumbles about the same frequency as the ridges of the blocks if that makes sense.
Tyre noise ? Some tyres are noisier than others and you’re sat almost on top of them. Mine are supposed to be one of the quieter makes but they still roar on rough surfaced roads…more noticeable with the hood up than down.
I would also suggest the tyres, as well as checking the drain flaps.
The six year old OE Bridgestones on my NC were deafening, hood up or down, but the Dunlops NickD fitted for me are still blissfully quiet after three years, I can even enjoy the exhaust and hear the stereo.
The OE Toyos on our Mazda3 were very noisy from new especially on concrete or a rough surface, louder than the tyres on the NC. When the Toyos wear out I’ll be fitting something else.
Get your passenger to press down on your rear parcel shelf as the rattle is happening, if this stops it look at the rear roof bar (don’t know how better to explain it) with the hood up, you’ll find it just touches the rear shelf.
I cured mine by using a length of split foam, the stuff they use to lag pipes with, and wrap it around the bar.
It sorted mine.
Baffle described as flaps in the link below. They block any road noise transmitting up the drains. They are just inside that outlet under the car as shown, one each side
