Mysterious noises from my Escort

"Billy H" wrote in news:438dfcc1$0$18532$ snipped-for-privacy@ptn-nntp-reader02.plus.net:

Without hearing, and/or feeling, it is hard to tell. It is hard with sometimes too. The symptoms would point to something on the right side drive train, but any loose piece of sheet metal can act like that. Loose exhaust and catalytic converter heat shields are often the culprit discovered after long periods of fixing things. I'd put an eye on the motor mounts as well, they can allow the engine to shift enough to cause vibration in otherwise quiet sheet metal. Could be a delamination in a radial tire sidewall as well, typically seen in old but not worn out tires. Can you make the noise by revving the engine with the car stopped? That will tell you a lot. If so you should be able to find it by ear. Drive down a hill and put it in neutral and/or turn the engine off (watch out for loosing power steering and brakes). Does the sound go away?

Turn the radio up loud enough so you can't hear it?

Regards Kevin

Funnily enough this one cures the problem!! The really wierd thing is it comes back when I turn the radio off. :/

Dear Billy H:

I'd check the fuel system. Possibly a "dismounted" fuel pump, or injector lines contacting something they shouldn't. I have absolutely no confidence in this suggestion, so don't spend money investigating it.

Could you get a little more into a description of "rhythmic humming"?

David A. Smith

Huuuummmmmmmmm

-- Regards,

John Stevenson Nottingham, England.

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Dear John Stevenson:

"John Stevenson" wrote in message news: snipped-for-privacy@4ax.com...

No way!! He said a Ford Escort diesel, not a Mazda. ;>)

David A. Smith

Buy a new radio ?

Mike

Don't quite understand why you would only change the bearing on the one side? I always change pairs of bearings and bushes as a matter of course.

But... if you are turning left then the unsprung mass of the nearside wheel will effectively reduce more than the effective increase on the offside (because the outside bearings will already be 'loaded-up' even at rest. Load is slightly exponential rather than purely linear in cornering). The noise (if it is the bearings) would then tend to change 'more' on turning left because that side would experience the greater apparent change in Mass-loading (the centre of gravity moves to the outside of the circle and the loading on the inside of the corner goes through the greater amount of 'change').

I would start with replacing the other wheel-bearing also.

Next ... check the exhaust baffle at the bottom of the bulkhead (I think they all had this)... my daughters' car which she had before emigrating (Escort Diesel) had a small blow in the exhaust just at the baffle plate... the exhaust gases were 'hitting the baffle and acting like a little drum. Inside the car it sounded awful, outside you couldn't hear the damned thing above the noise of the engine. It got louder/faster with engine speed. (Not just road speed) . Which is yours .. engine speed or road speed dependant? If it is engine speed related .. then obviously it is highly unlikley to be anything to do with suspension/steering. Road speed dependant .. it is likely suspension/steering.

As for radial tyre sudewall delamination as a suggested cause .... highly unlikely/improbable. Such, if it were to occur, is unlikely to give the symptons you describe. I haven't heard of delamination of car tyres being a problem for c.30 years .. you would see the effects of sidewall degradation (cracking and splitting first ... so this should be a really simple visual check).

Can't quite follow the logic of a noise being a 'balance problem' ... if it was a wheel balance problem you would not just hear it but also expect to feel it at it's resonant speed. Do you?

As this is OT for this group... you can drop me a offline email if you want to discuss.

ieb-aht-klokwurx-dot-koe-ukay

BTW .. my background includes (amongst others) automotive engineering so I do have some knowledge in this area.

I'd definately start with that 'other' wheel-bearing (especially if it is a humming sound rather than a graunching or rattling). Regards

Ian

"Billy H" wrote in message news:438dfcc1$0$18532$ snipped-for-privacy@ptn-nntp-reader02.plus.net...

Apart from the turning left my Mondeo had the same symptoms, getting worse over time. Two new rear tyres = instant fix.

I would have put £20 on a wheel bearing or related bit on the front end. Particularly since the rear tyres were in decent nick. Well known Mondeo problem (so I'm told).

Steve

If its got hydraulically assisted power-steering, then sounds to me like it could be the power-steering fluid pump. Turning puts more load on it, not necessarily the same on RH and LH turns.

Around the late 80's my boss at the time had a 5 series BMW which developed a humming noise, increasing with road speed, that baffled all the technicians for over a year. Apparently, this was not an entirely uncommon fault, and sometime after this period BMW found the problem and put out a service bulletin instructing that a piece of double-sided tape should be placed between the very thin plastic trim strip at the bottom of the windscreen (outside, not inside the car) and the screen itself. The result was an instant fix, as the wind pressure/speed had been causing this to resonate against the glass.

Perhaps something similar may be occuring with a piece of external trim or engine sheilding?

Peter

"Billy H" wrote in message news:438dfcc1$0$18532$ snipped-for-privacy@ptn-nntp-reader02.plus.net...

Thanks all!!

The noise is definitely not power plant related, I base this on the fact of my running the car with the engine off, the noise is the same.

Mr Stephenson is partially correct, it is huuuummmmm but with a little huuuummmmmm HUMMMMM huuuummmmm tempo to it, i.e. it has a discernable wax and wain, althought the timing between these is imeasurable with my stopwatch!!!!

I have in mind the rear wheels, although I was certain it was the front.

I shall change the other front bearing whenever I get the opportunity, along with the second wishbone.

There is no resonance, I had a front wheel with balance problems causing a big pull to the left but cured it with a change of wheel, and the wobble now is not noticeable if there at all.

Rear wheel change seems best next course of action.

Thanks again!

"N:dlzc D:aol T:com (dlzc)" wrote in message news:LErjf.10514$dv.8256@fed1read02...

I only changed the one bearing as I was convinced the problem lay in the one side. One mechanic I spoke with is baffled. The other said it sounds from my description to be the offside bearings.

I was told to let it develop, and I may well have ot if it is not fixed by replacing wheels and bearings.

Do you have think it could be CV joint? My father says they tend to click if they need replaced, this noise is not a click, although the humming is more akin to a vibration (although the car does not shake) than to a flute or trumpet!

Regards the bearings, the wheels do not and did not wobble vertically when given the grip and push-pull procedure, they did wobble a little left right but I am told this is normal.

The local scrapy could sort your problems, have it crushed, give it a decent burial!

At 12 years old for a Ford it is time to die......

See if it is still humming then.

If it still makes a noise call in Buffy.

:-))

Rich

Dear Billy H:

Let's work on nomenclature. You are in the UK. A turn to the left will place more load on the driver-side bearings, suspension, and depress the wheel further up into its wheel well.

What side of the car is the "offside"?

Google hum "CV joint" ... only 777 hits. You could decide based on some of these if it sounds like your problem.

Sounds right.

I notice that you said elsewhere that the noise continued after the engine was turned off.

When did the noise start? Before or after correcting the wheel balance by changing the wheel?

Is the tire(s) installed identical to the ones that were on it before? I am curious if you got a different profile, and are contacting some of the bits (metal or plastic) inside the fenderwell.

How much transmission fluid is in the tranny?

Is the same noise made when going backwards, and making the same type turn (or can you not safely go that fast)?

David A. Smith

"N:dlzc D:aol T:com (dlzc)" wrote in message news:NrNjf.10661$dv.5551@fed1read02...

based on the nearside being nearest the kerb and us in UK driving on left, offside is right.

began after some work on the alternator. that had me flummoxed. but am quite sure it is not the alternator!!

don't know, need to check. makes noise when tranny disengaged.

unsafe.

Does it have electric fan? Bearings! Water pump, alternator bush, Is it overhead cam? cam belt adjusting wheel bearings? All these can make the noise you describe. Maybe noise is coming from somewhere different than you have been looking. Just coincidence turning corner seams to alter noise?

Just thinking, doesn't power steering pump squeal if low on fluid?

Lionel

Take fan belt off and do a short trip to test. Will be Ok in cold weather for a couple of miles with no water pump

This will then eliminate one area.

-- Regards,

John Stevenson Nottingham, England.

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Try swapping the tyres from wheel to wheel. If it's a tyre proble

(which I don't think it is), this should highlight it.

Since it's dependent on the speed of the vehicle and not the engin (apparently) it has to be suspension related. Check for anythin rubbing against the wheels or axles like loose cables or mud flaps Sometimes it can be the simplest things. Does the pitch of the hummin go up as the car goes faster? Try jacking up each driving wheel i turn, putting it on axle stands (well chocked obviously) and run it i gear (assuming it doesn't have traction control). Or it could be bearing in the transaxle/gearbox where the drive exits the box

-- DX-SF

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