A lot of noise, but from where? V6

[markdswan]

Hi All,

Our V6 has gradually started making a lot of whirring noises. Best described as a mechanical metal on metal noise (bearing noise?)

Same whether in gear or not, seems to be coming from near the alternator/fuel pump area. Varies with revs.

All fluid levels checked and stable, drives absolutely fine, but the noise has got gradually worse. It sounds very much like a bearing noise, but from where?

How can I start to identify which part is to blaim?

The van has had a new alternator and water pump in the last 6 months

[Simon Jones]

Try it with the air con on and off. It may be the compressor pump bearings.
BTW, the fuel pump is in the tank rather than on the engine

[markdswan]

Thanks Simon,

Noise is the same with and without air con running. The noise seems to be coming from the alternator side, I think this belt runs the alternator and the power steering pump. I see mention of taking off the belt and turning the alternator by hand, is this easy? How do I remove the belt?

Mark

[cheffy34]

take a long bar to them and take a listen, it is difficult to tell between steering pump and alt as the bracket for the alt is bolted with the pump, i had a simaler noise turned out to be the dizzy bearing after talking to a man noise always travels through an engine IME, your water pump isnt a million miles away either but looking back that has been done. is it always there or just when he gets hot

Dar

[stuart_indalo]

I know this is a long time ago but I too have a similar noise on my V6. My garage had a look today and seemed to think it was coming from distributor. They didn't dismantle further without an engine manual.

Can the distributor be serviced or was it a replacement job?

[Simon Jones]

I wouldn't have thought that the bearings in the distributor would be at fault, but for £60 you could try an alternative one and if it's no better, then just sell the original to get your money back:

http://www.ebay.co.uk/itm/MAZDA-BONGO-D ... 417153d262


I've got one of these and it's very useful for tracing noisy things:

http://www.machinemart.co.uk/shop/produ ... tethoscope

[mikeWalsall]

By todays standards the V6 is not as sophisticated as 'modern' engines .. I reckon some garages are intimidated because of it's size and location ..

[rita]

Hi stuart_indalo,if the drive belts are removed and the sound dissapears its not the distributor,if the noise persists it MIGHT be the distributor.

[stuart_indalo]

Thanks for the replies the belts were taken off and the distributor considered to be the culprit. So I think it is an ebay investment time.

[stuart_indalo]

If I were to remove the distributor are there any issues to watch out for? Also where are the timing marks and what should they be set for given I'm running on LPG? I suppose though that the timing is fine now so identifying the marks will show what the current setting is.

[cheffy34]

Thanks for the replies the belts were taken off and the distributor considered to be the culprit. So I think it is an ebay investment time.

if it is any concilation my replacement dizzy that i changed because of the bearing is also now beginning to show bearing noises, must be something in the air at the moment

Dar

[cheffy34]

The dizzy bearing isn't unheard off iv'e had two and heard of a couple of others over the years.

Dar

[stuart_indalo]

Used dizzy arrived today so fitting soon. Any issues around fitting? I have the workshop manual arriving soon and will be able to strobe the timing.
I'll search the forum for suggestions for timing advance on lpg.

[Simon Jones]

When I had my LPG fitted, I was advised that the timing should be left totally standard. I did try to adjust mine, but apart from the markings being very faint (which I can deal with), the instructions regarding shorting the pins on the diagnostic socket didn't seem to tally up with what the strobe was indicating.

[mikeWalsall]

Personally I have never seen any comments on Bongo Fury on differing the ignition timing when running in LPG ..

I had always assumed (wrongly) that the ignition would have been better to be retarded slightly ..

But according to LPG forums this it totally wrong .. as LPG is as an higher octane level than petrol .. a couple of extra degrees of advance maybe beneficial ..

Various (reasonable) reasoning are, that both the petrol and LPG systems are controlled via the ECU which automatically .. usually in relation to a knock / detonation sensor give the information for the optimum point for the sparkies .. to (safely) be sparking ..