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Burning smell, faint grey smoke, battery light


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rafale_05
User

Apr 29, 2012, 4:18 PM

Post #1 of 20 (36119 views)
  post locked   Burning smell, faint grey smoke, battery light  

I've been getting a burning smell along with faint grey smoke and a battery light on the dash. The smoke appears to be coming from the upper left corner of the engine compartment. Also, the smoke comes inside the car if I turn the fan on.

The weird thing is that this only happens on startup, or when the car is idling. If I give the engine some revs or keep driving, everything is fine: no burning smell, smoke or battery light.

This has been going on for at least two or three weeks now, on and off. Anyone have an idea as to what this might be?


(This post was edited by rafale_05 on Apr 29, 2012, 4:22 PM)


Tom Greenleaf
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Apr 29, 2012, 4:42 PM

Post #2 of 20 (36084 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Smoke! Careful as if this is a failed battery they make hydrogen (more of a burned egg smell to me) and dangerous! I'm surprised it goes away??

Take a look underhood with a helper starting the car and see where the source is if you can would be my first move then move on from there but this needs to be attended to at once,

T



Discretesignals
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Apr 29, 2012, 4:44 PM

Post #3 of 20 (36079 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Might be helpful to know the year, make, model, and engine size of your vehicle also.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


rafale_05
User

Apr 29, 2012, 4:58 PM

Post #4 of 20 (36065 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

It's a 2001 Toyota with a 2.2 liter l4 engine.

The battery is fine. The smoke looks to be coming from the upper left corner of the engine bay, which is where the alternator is. I keep thinking that it's the alternator, but if that was the case, wouldn't my battery be dead by now?

A friend told me that it might be the belt tensioner, but that doesn't explain the smoke. The belt doesn't appear to be slipping, and there's no squealing noise either. Brakes and power steering are also working fine.

I should also mention that the smoke and burning smell isn't always there. The last time it happened was when I idled it for 30 mins in a parking lot. First the battery light comes on, and then there's the burning smell and smoke. It goes away if I keep driving and give the engine some revs.


(This post was edited by rafale_05 on Apr 29, 2012, 5:04 PM)


Tom Greenleaf
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Apr 29, 2012, 6:28 PM

Post #5 of 20 (36039 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Begs the question - How tight is the belt? If slipping it might make some smoke and a battery light but that would be severely loose. Remember that alternator works hard for a short while after starting up. From cold just let it run two minutes and carefully feel how hot alternator is would be informative. Belt tensioner if automatically tensioned as many are might be at the end extreme of its range?

Can alternators fail and burn - yes but usually not long before you are walking,

T



rafale_05
User

Apr 29, 2012, 6:40 PM

Post #6 of 20 (36031 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

I dunno if I can touch the alternator. It's right under the serpentine belt, and those things scare me when they're in motion. I've had issues with the belt slipping in the past, so I took it to the mechanic and all they did there was tighten it.

Supposing it's the belt tensioner that's failing... would that explain why I get smoke and battery lights at startup and when idling or at low RPMs?

Secondly, is replacing the tensioner a serious/expensive repair? I know this varies from make to make, but the car in question is a 2.2l 4-cyl 2001 Toyota Corolla.

Also, thanks for the help so far guys. I really appreciate it.


(This post was edited by rafale_05 on Apr 29, 2012, 6:43 PM)


Tom Greenleaf
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Apr 29, 2012, 6:50 PM

Post #7 of 20 (36017 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Don't touch alternator with engine running! Some are right up top and some you can barely see.

A self tensioner/pulley usually isn't out of control expensive but any silly thing can be a challenge to get at to replace.

We are trying here and want to see the end of this issue. Don't go wasting $$ tossing parts without some serious diagnosis as that is a waste and just a shotgun approach for finding a fix,

T



Discretesignals
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Apr 29, 2012, 7:21 PM

Post #8 of 20 (36009 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

The 2001 Toyota Corolla didn't come with a 2.2L. It came with a 1.8L and the automatic belt tensioner is hydraulically tensioned instead of being fix tensioned.


Might want to inspect the tensioner for leaking and poor tensioning of the belt. They did have a technical service bulletin out for a revised tensioner assembly for belt slipping and noise.

Tensioner assembly:







Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


rafale_05
User

Apr 29, 2012, 7:30 PM

Post #9 of 20 (36003 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Then it must be a 1.8L. This isn't the first time I've made that mistake.

I'll see if I can find the tensioner and give it a quick visual inspection. I don't really know too much about these things, so I might just end up taking this to the mechanic and getting them to double check it.

I'll also check the alternator temp to make sure it isn't being cooked. I'm guessing it's normal for it to be warm, but not hot to touch.


(This post was edited by rafale_05 on Apr 29, 2012, 7:33 PM)


Discretesignals
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Apr 29, 2012, 7:55 PM

Post #10 of 20 (35995 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

The alternator case is going to get as hot as the engine because it is bolted to a bracket that is bolted to the engine. If it is a burning rubber smell, that is the belt. If the alternator is smoking, it would smell like burning electrical wires. As Tom mentioned if the alternator was burning up from an electrical problem, you would be walking by now.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Apr 29, 2012, 8:00 PM)


rafale_05
User

Apr 29, 2012, 7:58 PM

Post #11 of 20 (35990 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

I can't really tell what the smell is, though. Others have told me that it smells like burning wires, but I think it smells more like burning rubber.


Discretesignals
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Apr 29, 2012, 8:02 PM

Post #12 of 20 (35988 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Smell the alternator. If it has an electrical burning smell to it, you will definitely be able to tell. You can't mistaken that smell for anything else.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


rafale_05
User

Apr 29, 2012, 8:05 PM

Post #13 of 20 (35984 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

I'll try it and see what I find.

What about touching the belt after letting the car idle for about 3-5 min? Is it normal for serpentine belts to get hot or does that only happen when they're slipping?


(This post was edited by rafale_05 on Apr 29, 2012, 8:07 PM)


Discretesignals
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Apr 29, 2012, 8:14 PM

Post #14 of 20 (35975 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Grab the belt and pull on it. It should be tight. If you pull hard enough, you'll be able to make the tensioner retract. It should spring right back after you let go of the belt.

Does this only happen if you have the AC turned on?





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Apr 29, 2012, 8:15 PM)


rafale_05
User

Apr 29, 2012, 8:28 PM

Post #15 of 20 (35968 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

No, I never use the AC anyway. I'll let you guys know what I find out tomorrow.


rafale_05
User

May 6, 2012, 1:23 PM

Post #16 of 20 (35898 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

So the car came back from the mechanic, and they said they couldn't find anything wrong with it. They checked the alternator, and apparently it's charging fine. They even let it idle for a few hours, and they still weren't able to get it to smoke.

This morning I started the car and it happened again. First the battery light, then a whining noise under the hood, followed by the faint grey smoke and burning smell.

I let it smoke for a while and then turned the engine off to try and pinpoint the smoke's location, and it still looks as though it's coming from somewhere around the alternator. After I started the car again, everything was perfectly fine. This is getting to be pretty frustrating.


(This post was edited by rafale_05 on May 6, 2012, 1:26 PM)


Tom Greenleaf
Ultimate Carjunky / Moderator
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May 6, 2012, 1:31 PM

Post #17 of 20 (35891 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Not going to re-read this thread. It's time for this to go for days if need be for pros to check out. Rent a car if need be like anyone would have to. This still has the propensity to be dangerous IMO so don't let it go on!

Tom



Hammer Time
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May 6, 2012, 2:32 PM

Post #18 of 20 (35883 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

Sounds like either the alternator or one of the other pulleys is locking up and causing the belt to slip. You will have to check closer.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



crashedhdd
New User

Jul 8, 2014, 10:12 AM

Post #19 of 20 (28159 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

I have a 99 nissan altima. Lately I've been seeing smoke coming from under the hood and it smells like electrical wires burning (maybe the shelac on the alternator windings). It only happens while at idle and on particularly hot days. I opened the hood and I can see smoke coming directly out of the alternator (where the windings are visible). Anyone know what causes this? Is it just age or can something be causing the alternator to do this? I don't hear any noises that would suggest the bearings are bad or dragging. The battery is charging fine and starting the engine is ok too. Car runs nice otherwise. I'll pull out the alternator and replace it but I'd like to know the cause. Thanks for any input.


(This post was edited by crashedhdd on Jul 8, 2014, 10:13 AM)


Hammer Time
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Jul 8, 2014, 10:16 AM

Post #20 of 20 (28157 views)
  post locked   Re: Burning smell, faint grey smoke, battery light  

If you need help with something please start a question of your own and not hijack someone elses.

Please read the FORUM RULES



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.







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