timing belt whine?

[trader]

Well I gave my MX a birthday present this week and its not entirely happy. A new timing belt (including tension/idler pulleys) which has gone together okay but has a slight whine a bit like a supercharger. I re did the tension as per the book and have about 10 mm deflection. The whine is still there. Has anyone else had this problem? Can you just back off the tensioner pulley away from its tension point to give more play or do I just put up with the noise?

[StanTheMan]

are you sure its not the waterpump? they can make a noise too. Did you replace that?

[trader]

Yes I did put a new pump in. I suppose if I took off the fan belt and the noise goes away that is my problem..

[Steampunk]

I'd say that you may not have tightened it enough.

[gobsmax]

i've got a similar "problem" when i got my major 100k service, belts + pump....could only notice it when the windows was down or at low revs

[Jace]

I've got the same problem, from 2050rpm to 2200rpm, mostly. The Mazda "specialist" I took the car to for a major service and waterpump replacement told me it would be gone after a week, that it was just the belt stretching out initially. He's a bullshit artist.

[wun911]

I heave read that upon installing the belt:

You put the tension spring into place (you may want to get a new one)

you turn the crank (21 mm bolt) 1 and 5/6 turns and it will reach a tension mark (this is the extra mark that is just left of the TDC mark...

you then tighten the tension idle pully to around 38 pounds...

you can now remove the tension spring to save weight....

now that it is fully tensioned you then turn the 21 mm bolt to TDC again and make sure all the timming marks on the cam gears line up...

you may want to replace the ps /ac belt and the water pump / altinator belt with new ones I hear they have orientation...

[blehbear]

Exact same problem here. Car seems to be working fine though. dríven about ~3000kms since the service and the whine still isn't gone. Sounds like its coming from the timing belt.

What brand timing belt are u using? And did u use aftermarket tensioners and springs? Just out of curiosity... I am using gates blue timing belt and aftermarket tensioners and springs bought from mx5parts.co.uk

[StanTheMan]

I heave read that upon installing the belt:

you can now remove the tension spring to save weight....

OMG, OMG, OMG.

LOL. do we have slammer the 2nd ?

I hread you like
to make the car on a diet.

[trader]

Surprised as to how many have this problem. Today is a new day so not giving up just yet. Like you blehbear I got all new stuff from UK parts - my belt is a gates (not blue). I'm going to pull off the drive belts first to make sure it's not the water pump, then reset the tension pulley. If it is the same as before I'm going to move it about 2mm from where its now set.

[de Bounce]

Was watching a video from Mike King re fitting a timing belt to a MX5

In part 2 he talks about a belt that is adjusted too tight will whine
Follow the link here and start it at the 7.00 minute mark.

He appears to do a couple of other good videos

Good luck

[wun911]

I was also suprised that its not on that tight... I reckon the PS AC belts are on tighter....

[StanTheMan]

fantastic vids.

maybe we should put those in with a sticky?

Okibi?

[wun911]

thats a really good vid

[trader]

Yes de Bounce I was aware of those vids and the mx5 unleashed sight (I purchased my rocker gasket from Mike - easy and quick to deal with). I used his method yesterday but still have the whine. Like Wun911 I dont see the purpose of buying a new tension spring as I'm already have the tensioner about three mills from where it should be. The belt deflection is about 11 mm and it looks slacker than in the video. Going to have one more go (another 2mm) today. We are lucky in Canberra to have Russell and Dave (Carco) who have been giving advice - no problems with a whine just annoying. They think some belts have a rough back surface which may cause the whine. I notice in many sights people have had the same problem. Will keep you posted.