Advice - Tensioner or Alternator

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T

thesoupnatzi

Joined
Oct 30, 2010
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3
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Have a 99 with 147K. Been sitting for about 3 months. Started no problem but I heard a subtle whine coming from passenger side of engine. Drove for a couple miles (3 starts) [STRIKE][/STRIKE]and then battery light comes on, abs, lights dim and shuts off and dies. My questions are:

1. Is it alternator or belt tensioner?
2. What is easiest way to find out which one is issue?

Thanks.
 
Check your battery, it may be bad or need about 2 hours drive on HWY to charge. Remember to grease battery post after cleaning, it is a must-do PM.

Subtle whine may be power steering pump, flush with M1 full synthetic ATF, search in mud for how-to it is very easy.

As far as checking tensioner & idlers bearings; use mechanics stethoscope or long screw driver to listen to bearings. If bearings bad they can be pressed out and replace for ~$5 or just buy new pulley assemble(s). See FAQ section of series 100 and download a 2004 FSM under maintenance, which gives test for tensioner.
 
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It is either your alternator your battery or both. Tensioner will just whine but has nothing to do with the battery or charging of the system, I just replaced my tensioner due to whining.

From you symptoms it sounds like alternator.
 
Just checked and the battery is a little over 6 yrs old. Hoping its the battery:)
Will replace tomorrow and see what happens.
 
Take it and have you battery and alternator load tested at any auto parts store. The fact that you lights are dimming and then you vehicle is dieing makes me think it is the alternator. your battery might be weak but your vehicle won't die unless the alternator is going.

You might need to replace them both.
 
6 yrs is old for most after-market batteries. I'd go on long HWY drive first, before load test. Hopefully you'll not need alternator, new OEM big $$. Aftermarket re-manufacture can be junky, so inspect closely if it comes to that. You can rebuild your alternator to save a few$.
 
Old batter showed 11.6 on voltmeter. New batter showed 12.5. Put in new battery and she started right up. With engine running and no load voltmeter showed 14.4 so can I assume that my alternator is still ok? :bounce:
 
I would not assume your alternator is ok, 11.6 is low but the fact that your vehicle died make me think it is your alternator. You will know in a couple days if the alternator is working or not?

My experience with Chevy Trucks, Jeeps, Broncos and Land Cruisers is I have never had my vehicle die unless it was the alternator, just my experience.

Keep posting I am curious to know what happens.
 
I would have agreed with you about alternator, from my hot rod days. I've not had any issue with my LC's alt, so no experience here.

But had a very interesting situation at a car lot and a GM Astro van. We started with a jump, but couldn't keep running, working throttle revving but keep dying. Lot boy said I'll put in new battery so you can drive. Well I said don't bother it won't make any difference, we started so it must be something else. He ignored me an put in the battery, I with my vast experience said will not matter. I had egg on my face, it ran perfect with new battery. I guess newer electronics just aren't wired as the old generator vehicles. The amp supplied are key to proper ECM/ECU IO, I guess, out of my pay grade but made all the difference.

Hopefully OP got off cheap.
 
Taken from my vast/superior experience and knowledge (stupid over thinking), just because you can get it started, doesn't mean it will run properly on a battery that's completely done. A fresh battery and test the charging is in order most of the time.
 
I had a similar experience in another late model vehicle (01 BMW 740). Again battery was about 6yrs old and was original. One day car does not start and a Transmission Fail light comes on. Was able to jump it but light stayed on for about 30 miles. I saw Benjamins flying out the window everytime I saw the tranny light driving it for 30 miles

Why would a tranny light come on due to a bad battery? I asked a BMW mechanic and he asked me if I knew what BMW initials stand for.....of course I said Bavarian Motor Works. His response was an astounding WRONG.....it stands for Break My Wallet.

Point of story....i would agree that modern cars with sophisticated electronics are wired differently. Will post after a few starts and drives to see if a new battery did cure this problem or is it my alt.
 
thesoupnatzi said:
Point of story....i would agree that modern cars with sophisticated electronics are wired differently. Will post after a few starts and drives to see if a new battery did cure this problem or is it my alt.
Click to expand...

A failing battery can cause all manner of symptoms that are not obviously connected but are all caused by low and/or fluctuating line voltage. Six years is well beyond a typical lead acid battery life, so there's a good chance that a new battery will clear up your problems. If not, it was due for replacement anyway.
 
Along the lines of a weak battery, I mean one that is still cranking well-enough to start engine but just not up to par:

1) Would it work alternator harder than normal?

2) Would this show-up on our dash gauge?

3) Would this affect ECU/meters/sensors/injectors/fuel-line pressure etc...?
 
Any basic auto parts store can test for a bad battery or alternator - advance, pep boys, auto zone, whatever. My original toyota panasonic battery lasted well over 6 years.

If you installed a new battery go for a long drive or several short trips around town and you will know pretty quick if its your alternator. The alternators job it to keep charging the battery so it will slowly drain from starting the engine and running all your electronics if its bad. A bad ground can also cause a car battery to slowly drain but this is much less common nowadays. Unless you have a bunch additional accessories and electronics installed this likely isn't your problem.
 
Hi
I'm a great believer of keeping a small battery charger connected to the LC when not in use for a few days or more.
The wiring system in the 100 series has a slight power draw whilst in the OFF mode.
And alternators will never charge batteries to 100% SOC (State of Charge)
I use a small Ctek unit.

Peter
 
Interesting you mention the slight power drain. I turn my headlights to auto 10 yrs ago and never gave it another thought. I've just notice the owners manual states turn headlight switch to off if parked longer than a week. I suppose the wireless remote, engine immobilizer & auto power shutdown all are parasitic as well.
 
LED12volt said:
I use a small Ctek unit.
Click to expand...

^ +1. Ctek make great maintenance chargers. Perfect for storage, but alos great for recharging lead/acid and sealed coil batters [Odyssey etc] and keeping them healthy.
 
Update

Turns out it was the battery after all. Did all the alternator tests with v meter, drove it around for a whole day with several starts and about 50 miles. Knock on wood, no issues.
 
2001LC said:
Check your battery, it may be bad or need about 2 hours drive on HWY to charge. Remember to grease battery post after cleaning, it is a must-do PM.

Subtle whine may be power steering pump, flush with M1 full synthetic ATF, search in mud for how-to it is very easy.

As far as checking tensioner & idlers bearings; use mechanics stethoscope or long screw driver to listen to bearings. If bearings bad they can be pressed out and replace for ~$5 or just buy new pulley assemble(s). See FAQ section of series 100 and download a 2004 FSM under maintenance, which gives test for tensioner.
Click to expand...

thesoupnatzi said:
Turns out it was the battery after all. Did all the alternator tests with v meter, drove it around for a whole day with several starts and about 50 miles. Knock on wood, no issues.
Click to expand...

Great, you did remember to grease battery post?

If not it will happen again.

If older battery have a load test also, free at most parts stores.
 
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