Very Loud High Pitch Whine in Gear 1/2/3, Gear 4/5 has no Whine

Technical Area Engine, Transmission, Exhaust etc
2

Hi all,

 

I’m a proud new owner of an:

 

1998 Mazda MX-5 1.8 S 2dr MKII 130k Black (not sure if it has an LSD?)

 

Just bough it last week but noticed the engine has a very loud whine noise which appears to be coming from the gearbox, its soo loud even pedestrians look at me thinking is this some kind of electric car because it sounds just like an electronic motor, its a strong solid perfect whine noise.

 

This whine makes a noise when in the first 1/2/3 gears only. Soon as you change up to 4th or 5th it disappears completely, the whine also goes when your out of gear or stationary.

 

Note, if you are in gear 1/2/3 but going downhill and not applying any gas, it doesnt whine, it has a medium whine on flat roads, and very loud up hill.

 

The car was kind of sold with this whine noise so taking it back isnt really an option, and i only paid £900 for it.

 

I’ve seen on ebay 2nd hand gearboxes for £50-£75, would my only option be to change the gearbox? Or would changing the gearbox oil have any hopes?

 

If changing the gearbox is the only way, is there any guides or videos on this forum on how to remove/refit the gearbox with pictures or videos? I’m kind of a beginner/semi skilled with car maintenance. Or would a local member be up for giving me a hand for some cash in hand?

 

I plan on attending the West London: Monthly Pub Gathering (01 June 2015 19:30) if anyone would be able to give it a look/listen and maybe provide tips on gearbox removal or offer to help out one weekend for abit of cash in hand.

 

As always, any advice would be greatly appreciated, thanks in advance =)

 

p.s I’ll try and post up a video later on tonight

3

My blue Mk1 does NOT have this noise… it’s pretty standard.

My red Mk1 DOES have this noise… red 'un has a K&N cone airfilter fitted, replacing the standard airbox/filter - the noise is noticeable when demanding power uphill in lower gears - it’s air induction noise.  At speed you don’t notice any noise because external wind-noise takes over!

Do you have a modified air intake fitted?

Cheers, Tim

4

Check the gearbox oil level, better still drain the oil and check for debris in the oil replace the oil with a good oil something like Castrol Syntrax gearbox oil whilst you are under the car just check the diff oil no harm in checking. I have owned all three marks of mx5 and none have had a whine at all.

5

^^^As above, got to be worth doing first before anything else^^^

6

Having had a listen this evening to Ricky’s car while he was driving I can confirm the symptoms are as described; 1,2,3 are very bad with heavy gear/bearing grinding noise under load and a hint of it on over-run as well, but silent as one would normally expect in 4 or 5. It is not the diff and not induction. This suggests to me that there is a bearing failure in the box affecting the way the lay-shaft meshes with the main-shaft.

There are a few possibilities because I’m not 100% sure of the layout inside the Mazda 5 speed box, but I assume 4th just links input and main-shaft and 5th is an overdrive using the reverse shaft, neither of which will stress the lay-shaft. My guess then is that the problem lies in the intermediate bearing between input and main-shaft, or less likely the lay-shaft bearings.  The gears might still be OK, but it does not sound healthy and is possibly full of bits of needle roller.

My reluctant suggestion is to change the box.

:^(

 

7

Hi All,

Thanks for all the replies and thanks Richard for taking the time to have a look at the car. It looks like I have to change the gearbox unfortunately.

Would anyone know any of MX5 club members who would be up for the challenge for abit of cash in hand business to swap out the MX5 gearbox with me if I was to source a good used 5 speed gearbox? What I’m sort of looking for is someone to help and provide a guide/walkthrough and assistance to change it, I wouldn’t mind either going to your place or carrying out the work at mine.

P.S, I’m located in the Croydon/Kingston/Heathrow area and wouldn’t mind going for abit of a travel to your location.