Whining from engine. Lights dim get brighter with rpm

[daveyboy123]

Hello all. Hope you are able to help.

My focus acted up the other day. I started the car as normal but got a very very loud whine, almost sounded like a hair drier that rose in pitch with rpm. Just over 1000 rpm the noise was very loud, when I slowed down the noise gradually went until the revs increased again.  

When I pulled up I could smell a burning smell through the blowers. 

After it was left overnight I started in again and although noise there it wasn't anywhere near as loud as before.

That's when I also noticed that at idle the electrics in the car would be OK until I gave it some revs. As the revs increased things sped up. So the fan at highest setting sounded a little on the slow side, as soon as increased the revs the fan speed also increased. I also noticed same thing with lights, the lights would brighten a bit with revs and the dim a little once revs decreased.

If I have headlights on and turned the fan on, each setting on fan would every so slightly dim the headlight more and more. Turning the steering wheel also effected lights as they dimmed slightly when turning wheel.

Upon searching, everything I found indicates alternator or voltage regulator causing issues.  Mechanic checked alternator and said that voltage output is normal.

As I've experienced more issues regarding everything feeling under powered until revs increase I feel it's potentially voltage regulator.

What does everyone think? 

Ps I have had a new battery within last year or 2.

Thank you all

 

[Tdci-Peter]

1 hour ago, daveyboy123 said:

If I have headlights on and turned the fan on, each setting on fan would every so slightly dim the headlight more and more. Turning the steering wheel also effected lights as they dimmed slightly when turning wheel

Sounds very much like alternator to me. Or it could be the fat wires from the battery. Negative goes to the engine (near starter motor normally), and the the body. Positive goes to the main fuse box, and to the starter & alternator. Inspect & feel all these connections, for corrosion, loose joints, or floppy feeling wires near the ends, that may indicate a partially severed wire.

One of those cheap cigar lighter mounting voltmeters (eg from Ebay) would be useful, though I would compare its readings using a multimeter on the battery terminals before trusting it. Even if a bit inaccurate, it would still provide a guide.

You should be getting 14.2v to 14.8v at the battery with the engine running. This would be idling with minimal electrical load, or about 1500rpm with headlights, wipers & heater fan all on. (It may be a bit lower for a minute or two after starting.)

It ought to be investigated & fixed reasonably urgently, before the battery goes flat, and permanently loses some of its capability. Or put the car on charge overnight, using a suitable, fully regulated, charger.

[artscot79]

depends on the load at the time blowers on lights aircon all add extra load

[daveyboy123]

This is the thing, when it first happened it was a very loud whine that I could hear over radio. this was accompanied by a burning smell. 

The whine has died down a little but as I say it's still there and mechanic has tested volts coming from alternator and they appear fine.

I can't ever recall the car electrics being as slow at idle though. even the wiper seems slower and like I say any electrics that are on seem slower at idle but if I rev engine the fans speed up or lights get brighter. 

I'm hoping by changing the alternator it at least fixes some of the issue but the whine could potentially be something else?

[drsdriver]

My money is on the alternator, the smell you described is probably from the alternator . A battery smell is like rotten eggs, so can rule that out. 

As above , check voltage from the battery when idling, or a cigarette voltage meter u can pop in the cigarette holder. 

 

[daveyboy123]

So even though the volts are fine it could still be the alternator emitting the noise?

The more electrical things that are on does also seem to effect the noise/pitch of the whine so guess apart from alternator there wouldn't be anything else that could cause this would there?

[BOF]

It is possible that rather than the alternator it is the alternator drive belt that is slipping. This would cause more of a screaming nose on start-up and would typically be worse wet and when on load and at start-up.

On the other hand the alternator bearings (or one bearing) might be shot and that would cause a whine/rumble but wouldn't themselves cause a burning smell.

When you are looking at the wiring be sure to check for any sign of overheating (eg insulation looking as if it has partly melted away from the wire) as that could also be a clue.

 

Quote

This is the thing, when it first happened it was a very loud whine that I could hear over radio.

Could you only hear it over the radio or was there a mechanical noise as well? If you could hear it over the radio (and you do mean 'through the radio loudspeakers' rather than just 'louder than the radio?) I think it has to be alternator/regulator.
 

[daveyboy123]

The alternator belt is fairly new to be honest. About a year or 2 old and haven't done loads of miles since having it done.

This is the first time the noise has occurred since having the belt replaced.

There's no screaming or anything on startup either. 

I did read the the voltage regulator could in fact whine when it's on its way out.

No sorry I didn't mean the sound was through Speakers. The sound was just very loud and could hear it louder than the stereo but no it wasn't coming through the stereo or Speakers itself.

Also though as mentioned before I've been getting the strange power issues where the lights would get brighter when engine rpm increases etc. Blower speed would also increase a bit with more rpm. I don't recall that ever happening before on the car and have been told that's probably a faulty voltage regulator.

Think it may be worth replacing the alternator and see if that fixes any of the issues. If the whine is still present then will have to keep seeing what else it could be.

[isetta]

from how you describe the first incident my first thought would be fan belt slipping and heating up due to slippage and causing the smell.  on my Focus I had some intermittent strange clicking noises around fan belt over a period of time and could not work out what it was. And then 100 miles from home on motorway it became clear what was on its way out. The bearing on the fan belt tensioner jammed causing the plastic tensioner wheel to melt (due to heat from fan belt sliding round it I assume) and fan belt came off. Needed a new tensioner. luckily I was in RAC who recovered car to my home. I fitted a new tensioner the next day. The clicking was the bearing failing before it jammed.

If I was you I would release the tensioner and take belt off. then spin everything and see if anything that spins on the belt feels bad.  Make sure you have a diagram or photo

[Tdci-Peter]

41 minutes ago, daveyboy123 said:

have been told that's probably a faulty voltage regulator.

There is no separate voltage regulator on these cars. Most of the regulating is done in the alternator.

The ECU also plays a part, it sends a modulated signal to the alternator, to set the power output, and receives back a signal about the alternator load. This is via the smaller three way connector on the alternator. Problems with this connector or its wiring can cause voltage problems, but does not really stack up with the whine & burning smell.

I am a bit concerned that it could be overcharging, ie on full power all the time. If the voltage rises above 14.8v, then urgent action is needed, or it will destroy the battery, then proceed to damage other electronics in the car, like the ECU.

I would investigate the drive belt & pulleys as Isetta suggests, check the voltage under varying conditions, including driving (the dash mounted meter helps here), check the wiring conditions, then, if problems were real and not obviously wiring, replace the alternator. If you do not have the facilities to do that, and the weather is not ideal!, then a good garage that seems to understand charging systems, will be needed.

[daveyboy123]

Many thanks for your replies. 

The mechanic I use did say that potentially it could be pulleys or tensioners etc but wasn't able to spin it fast enough to recreate the whine I was hearing.

It's all very strange and I've looked at belt and all appears to be OK. 

However, driving home this evening I did a few tests as I was getting the whining sound again which went with revs etc. So I noticed that when it was doing it the lights were on as well as blowers and also rear defrosted.  So I decided to turn blowers and defroster off and the whining sound almost vanished. Then I turned them all back on and noise reappeared again with acceleration etc. I got home and turned the electrical things on and again whining sound very much present. I turned it all off including the head lights and it was almost silent, whine was barely noticible. 

To me this indicates it's def something electircal and would this point more to the alternator than the belts and pulleys as if it was belt related then surely the noise would be present permently and not just when electrical things are switched on? 

[artscot79]

it's normal the higher the load the harder it works

[MickyG1982]

1 hour ago, daveyboy123 said:

Many thanks for your replies. 

The mechanic I use did say that potentially it could be pulleys or tensioners etc but wasn't able to spin it fast enough to recreate the whine I was hearing.

It's all very strange and I've looked at belt and all appears to be OK. 

However, driving home this evening I did a few tests as I was getting the whining sound again which went with revs etc. So I noticed that when it was doing it the lights were on as well as blowers and also rear defrosted.  So I decided to turn blowers and defroster off and the whining sound almost vanished. Then I turned them all back on and noise reappeared again with acceleration etc. I got home and turned the electrical things on and again whining sound very much present. I turned it all off including the head lights and it was almost silent, whine was barely noticible. 

To me this indicates it's def something electircal and would this point more to the alternator than the belts and pulleys as if it was belt related then surely the noise would be present permently and not just when electrical things are switched on? 

Has this all just started with the current cold weather?

Cold weather takes it's toll on older batteries which would mean the alternator has to work harder to power all the electrical items you have running. Turning them off reduces the load & will eliminate (or reduce) the noise if this is the case.

[Tdci-Peter]

1 hour ago, daveyboy123 said:

turned the electrical things on and again whining sound very much present. I turned it all off including the head lights and it was almost silent, whine was barely noticible. 

The tensioner is on the slack run of the belt, so increased alternator load will reduce the pressure on the tensioner a little, as the belt between crankshaft & alternator gets stretched a bit.

It could possibly be the a/c pulley or a/c clutch, as that feels the increased alternator load. But it is more likely to be the alternator, either mechanical noise from its bearings, or electrical & magnetic stress inside it. I would suggest a stethoscope or listening tube, but not near that belt! Not unless it was well secured, and impossible to touch the belt.

Voltage tests are still the real key here.

[daveyboy123]

7 hours ago, MickyG1982 said:

Has this all just started with the current cold weather?

Cold weather takes it's toll on older batteries which would mean the alternator has to work harder to power all the electrical items you have running. Turning them off reduces the load & will eliminate (or reduce) the noise if this is the case.

It's started recently but just before it got really cold. In actual fact it was when it was extremely wet and I did wonder whether water could have gotten into anything.

The noise though is not something I've ever heard before. I've had the car 5 years and it's never whined like it is now. Never mattered how many electrical things I've had on.

6 hours ago, Tdci-Peter said:

The tensioner is on the slack run of the belt, so increased alternator load will reduce the pressure on the tensioner a little, as the belt between crankshaft & alternator gets stretched a bit.

It could possibly be the a/c pulley or a/c clutch, as that feels the increased alternator load. But it is more likely to be the alternator, either mechanical noise from its bearings, or electrical & magnetic stress inside it. I would suggest a stethoscope or listening tube, but not near that belt! Not unless it was well secured, and impossible to touch the belt.

Voltage tests are still the real key here.

OK, can the voltage still be outputting normally even if the alternator is failing?

The noise itself is like an electric motor sort of whine that increases in pitch when you accelerate. If I press the clutch or reduce apeed then the rev drops right down and noise drops with it.

I guess the fact that it could be alternator it's best to get replacement in the hopes it cures the issue. Then if it doesn't we know that it must be tensioner or ac related?

If it was any of the other things other than alternator.  What's worse thing that will happen?

[Tdci-Peter]

3 hours ago, daveyboy123 said:

can the voltage still be outputting normally even if the alternator is failing?

I would say: No, there will be some voltage abnormallity.

But it could be fairly subtle, or intermittent. A couple of quick measurements may not reveal it. If there is a partial failure, so it is overcharging, the battery will absorb the overcharge up to a point, and regulate the voltage. That is how old dynamo and crude alternator systems worked many years ago. But the voltage will go above nominal limits (14.8v for silver calcium battery) at some point.

If it is undercharging, then the voltage will not hold up properly under load, especially at low rpm. But it takes some experience to tell, as a massive load (screen heaters etc) at low rpm would be more than a good alternator could deliver. But normal night time driving load (lights, wipers, fan) and 1500rpm should hold at well over 14v, as that could be a realistic state for long periods.

That is why I say a quick voltage check in a garage may not be adequate. A well equipped garage may have a clamp on current probe, and be able to measure the alternator current. This would diagnose certain other faults, like some heavy load always on with ignition on, that is making the alternator work too hard, or some unusual type of battery fault.

If the belt is removed, it should be possible to detect tensioner faults, just by feel, smoothness of the spring action, and any play or stiffness in the bearing. Plus damage to the wheel surface. Similarly with the a/c pulley. Also see if the whine changes when the a/c is engaged/disengaged, and that the a/c works ok.

4 hours ago, daveyboy123 said:

What's worse thing that will happen?

That is never a good question to ask!

In this case, the pcm (ECU) is part of the charging system. Damage to the Alt.Mon & Alt.Com circuits in the pcm is very, very unlikely, but would be the worst case here. Well, you did ask!

[daveyboy123]

Thank you very much for the answers.  Do do think that it's more likely to be alternator whineing considering it gets louder with more electrical load?

I think I may get it changed and at least it would narrow it down then if it didn't cure the issues? 

[isetta]

I would still be worried about the burning smell in the first message at the top.

We do not know where that came from.

Does anyone know if an alternator could actually catch alight?

I dismantled one once (in the days when people replaced the carbon brushes and regulator and rectifier packs in alternators) and the rectifier pack had melted.

(the rectifier pack is a series of diodes that converts the alternator ac current to dc current and is built into the alternator)

 

[daveyboy123]

Yes from what I've read on the Internet it does seem to suggest that a failing alternator will also or could also cause a burning smell as well as a whining sound. This is what keeps making me think it's alternator related.

That along with the fact the blowers and all electrics seem a lot less powerful at idle (i guess it may have always been that way but I've only just noticed it now)

If the alternator is changed and whine still occurs then I assume it can then only be a tensioner or possibly something to do with air con. However the noise doesn't change if air con is on or off so don't know if that makes a difference.

[Tdci-Peter]

1 hour ago, isetta said:

know if an alternator could actually catch alight?

I would say its almost impossible (in the full sense of self-supporting combustion), unless soaked in oil or diesel.

Electronic components, and the potting compounds in coils, are all rated for low flammability, so they will not burn without aid.

When electronic components overheat (I have seen plenty!), there will be smoke, very high temperatures, sparks, and some flame possibly while energy is still going in. And lots of nasty, fishy stink. But it will self extinguish & cool down once the power is off (engine stopped, or battery fusible link blown in this case).

From the start, it did sound like an electronic component somewhere, probably in the alternator, had failed, overheated, and burnt out. But I have been reluctant to categorically say it IS the alternator, as it is an expensive error if it does happen to be something else.

[daveyboy123]

Oh I know and as I say the mechanic who checked said same thing that upon checking it that it could still be the alternator but there weren't enough proof as such that it was in fact the alternator and yes you are right it could certainly be a costly replacement if in fact it doesn't help any thing but with this I think I may just have to give it a go and keep fingers crossed that changing over the alternator will stop the noise. If not then guess it's just got to keep listening out and trying to find the culprit.

 

[JIMMWX]

As has been said I would suggest that this is the Alternator causing this.  I had a very similar problem in a previous car I owned, an 08 fiesta.  The sound was exactly as described, but in my case there was no burning, it was the tensioner that was on it's way out.  A New Alternator solved this problem.

However, it is worth getting it looked at properly again by a Mechanic.  I had an Alternator fail on me once in an Astravan, it took out the battery with it and left the car completely immobile.  I had to get it towed to my mate's garage to be fixed.

In regards to one "catching fire" - unlikely, but as it is an electrical component, there's a likelihood it could melt some of the plastic components.  That and the electric wires melting a little is probably what is causing the smell.  Probably, I haven't seen the car nor am I a mechanic.

Hope you get to the bottom of it, and get it sorted.

[daveyboy123]

Yes it's very strange. The whine at its loudest was on the first day it occurred which happened to be when it was really wet outside. This also was the day I smelt the strong burning smell through the vents.

Since then the burning smell seems to have passed a bit as I don't smell anything at least any more and the whine is there but no where near like it was the first day it occurred. 

That's why I think it's almost like something burnt out or had some issues but I just don't know.

I'm getting alternator replaced next week hopefully so we will see then if it fixes any of the noises or strange power issues I've noticed with things like the blowers and lights feeling underpowered until touching the accelerator to get revs up.

 

[daveyboy123]

I have now had the alternator replaced and good news. The problems have now gone.

So the strange dimming of lights and brightening etc with more revs has now entirely gone.

The whine that was also present has gone entirely. So appears something in the alternator mus have burnt out and wasn't running correctly, even though the alternator was showing the correct volts. 

Many thanks everyone for your help.