Rough Idle and another question

[JimMadsen]

I recently had my serpentine belt changed when I had my oil done. I started out all set to do the oil myself, had just finished my wifes SUV, but couldn't get the drain plug to loosen. So I brought it to the shop for a el cheapo change and I would try again in a few months. While there it was seen the belt was going so they put that in. They also advised my harmonic balancer was needing to be replaced as it was wobbling. Having little cash I changed it myself. Yes, yes I know. I let them do the oil and serpentine while I replaced the balancer. But heck, I did my own front struts as well.

 

So this was all 3 weeks ago. I have been hearing a whine from the engine and a rough idle. So I bring it back to them thinking that they put the belt on, they can make sure it is right tension. Never mind I had removed it since then... but they remembered me! They still looked at it though because I had noticed the whine prior my work on the engine. They think I have a bad tensioner, but I think I just didn't make sure it was tightened back down enough after the balancer. Silly me loosened the bolt because I couldn't figure the easy way to take the belt off. I know how to do it now. So question 1 is: if the bolt was loosened, tightened back up, but has a slight wobble to the tensioner, I should be able to just put more torque on it to tighten and all should be well, correct?

 

As for the idle, they said might be the idle sensor. My throttle sensor is newer (about a year old) and I am not stalling. My RPMs look fine (hair under 1000 at a stop) and it runs the highway good. I just have a rough idle. Where should I be looking?

 

I do not have much cash, hence why I drive the sucker. But I am learning a lot on keeping it going. Thanks in advance for the help.

[RobertISaar]

if the tensioner wobbles(and it's torqued down correctly), there's a good chance that the pulley is bad on it or the tensioner itself is the problem. i've had both instances happen.

[Schurkey]

So question 1 is: if the bolt was loosened, tightened back up, but has a slight wobble to the tensioner, I should be able to just put more torque on it to tighten and all should be well, correct?

Unlikely. First Guess: Defective bearing. Time for a replacement pulley, or replacement tensioner.

 

Remove belt, spin tensioner pulley? Is it rough? Does the pulley wobble?

 

As for the idle, they said might be the idle sensor. My throttle sensor is newer (about a year old) and I am not stalling. My RPMs look fine (hair under 1000 at a stop) and it runs the highway good. I just have a rough idle. Where should I be looking?

1000 rpm idle IN GEAR??? That's WAY TOO HIGH.

 

1000 rpm idle in NEUTRAL??? That's somewhat too high.

 

First thing I'd do is check battery voltage with no load. Better be 12.6--12.7.

 

Second thing is to verify operation of the idle air control system (IAC)

 

WHAT VEHICLE IS THIS??? WHAT YEAR??? WHAT ENGINE???

[JimMadsen]

98 Chevy Lumina 3.1

 

Battery car off, 12.0v at outlet

Running in park 14.1v

 

Neutral: 1000rpm 13.5v

Drive, OD, R stationary: 900rpm 12v (climbs .3 when foot off brake)

 

I tightened the pulley and it no longer wobbles but I will replace anyways. Just need this, http://www.autozone.com/autozone/parts/Duralast-Belt-Tensioner/1998-Chevrolet-Lumina/_/N-ja6z1Z8gdap?itemIdentifier=136379_0_1690_ correct?

 

Then I can replace the IAC with this?

http://www.autozone.com/autozone/parts/Duralast-Idle-Air-Control-Valve/1998-Chevrolet-Lumina/_/N-ja6z1Z9gsof?itemIdentifier=2990_0_0_

 

I can probably replace one thing per paycheck (wife is out on maternity leave very very soon) and I bet the battery needs to get replaced sooner than later. So which should I takle first? Or is there something better than replacing? I don't want to look for used parts because new are cheap enough.

 

Thanks

[Schurkey]

98 Chevy Lumina 3.1

 

Battery car off, 12.0v at outlet

Outlet??? WHAT "outlet"? Test it at the battery terminals. If there's a big difference between battery terminals and, for example, the cigarette lighter socket, repair excessive voltage drop in the vehicle wiring.

 

12.0 volts is WAY TOO LOW. Battery should be 12.6--12.7 volts, no load. 12.5 is 1/4 discharged. 12.2 is HALF-DEAD. 12.0 is a disaster.

 

Running in park 14.1v

Acceptable.

 

Neutral: 1000rpm 13.5v

I'd have expected higher voltage when running in neutral. How can you have 14.1 volts in "park" but only 13.5 in "neutral"???

 

Is your voltmeter accurate and repeatable?

 

Drive, OD, R stationary: 900rpm 12v (climbs .3 when foot off brake)

Not enough voltage.

 

I suspect alternator is partially-toast. Could be defective battery. Test starting/charging power team for AC (ripple) and DC voltage, current supply FROM alternator, current draw from starter, battery load-test and parasitic draw. Do all these tests AFTER battery has been properly charged and shows 12.6 volts when the battery charger has been DISCONNECTED for an hour or more.

 

FIX the ELECTRICAL/STARTING/CHARGING power team BEFORE diagnosing the idle problem. Fixing low-voltage may give the computer, sensors, and outputs a whole new attitude, idle problem may cure itself.

 

I tightened the pulley and it no longer wobbles but I will replace anyways. Just need this, http://www.autozone.com/autozone/parts/Duralast-Belt-Tensioner/1998-Chevrolet-Lumina/_/N-ja6z1Z8gdap?itemIdentifier=136379_0_1690_ correct?

Did you TEST the pulley like I suggested?

 

Then I can replace the IAC with this?

http://www.autozone.com/autozone/parts/Duralast-Idle-Air-Control-Valve/1998-Chevrolet-Lumina/_/N-ja6z1Z9gsof?itemIdentifier=2990_0_0_

Did you TEST the IAC?

 

STOP REPLACING PARTS before you test them.

Edited November 17, 2012 by Schurkey

[JimMadsen]

I have a in-car battery tester which gives the readout. I do have a multimeter but have never tested the electrical system before. I am pretty new to fixing my own cars and am going at this with minimal car background. Although I can take care of a heart attack for you, I was very nervous before attempting an oil change.

 

Yes, I pulled off the belt and there is no wobble to the tensioner when tugging on it, and the wheel moves freely. I just put that in because, I would rather replace some parts on cheap things then wonder in the back of my head.

 

Is there a way to get at the battery without removal of the washer tank for checking and/or replacement.

 

It does not appear to be repeatable. I went out and rechecked using the same method at the outlet (which I acknowledge is not the best method, or the proper one) and got:

12.2 no load car off

13.0 park up to 13.7 when given a little gas

13.0 neutral up to 13.7 when given a little gas

12.4 drive

 

As for testing the rest of the system, like I said above, never having done it I am not sure how to start other than checking the battery directly. Can a auto store do a test? Are they able to without being able to access the battery without part removal?

 

What would be the best way to test the IAC after everything else is checked? I do not have a check engine light on. But again, this is something I wouldn't mind replacing at $30 if the testing itself would be pricey by getting diagnostic tools.

[Garrett Powered]

the battery needs charged

[RobertISaar]

98 Chevy Lumina 3.1

 

and here's where the odd tach readings are coing from. all of the 95-99 MC and 95-01 lumina clusters with tach always read higher than reality. not sure why, but GM did a poor job of calibrating the clusters back in the day.

 

just under 1000(on the tach) is close to a 700RPM idle. i command a 600RPM idle(and verified it via the datastream) when hot and it reads more like 750-800.

[JimMadsen]

Thanks for the info Robert. But the engine still sounds very rough even if the tach seems somewhat common to the engine. Then there is the apparent electrical problem...

[JimMadsen]

Went to Advanced Auto and had them test the battery and alternator. Here are the results:

 

Battery Test: Charge Required 11.16v Measured 500 CCA, Rated 540 CCA Temp 58 degrees

 

Starter Test: Low Cranking Amps Voltage 10.75V, Amps 0.2A, Time 6.00S

"Starter amp draw is low with ok starter voltage, check starter circuit for loose, worn or corroded wiring"

 

Charging System Test: No Voltage. No load 11.69V 0.0A, Loaded 11.69V 0.0A

 

I have to say that there was no difference between no load and loaded as my daytime running lights where on and while in idle (I did what the guy with the machine told me to do). But this also mirrors what I saw driving too and from work today. If RPMs under 2000, my volt meter plugged into outlet registered 11.7-12.2V. When RPMs above 2000 it would be 13.5-14.2V depending on where the RPMs where, going up correspondingly between Volts and RPM. I for one have no clue if the alternator is supposed to be kicking out while in idle or not. I know the definitive way is to remove it and load test it, and I am all for that if stores do it for free. Also the problem is one of needing a running car to handle all of the running back and forth.

 

While looking at alternators, is there anyone with a review of this one:

http://www.amazon.com/gp/product/B004J0WE92/ref=ox_sc_act_title_1?ie=UTF8&smid=ASQHPNXXVKB77

 

Thanks

[Schurkey]

Went to Advanced Auto and had them test the battery and alternator. Here are the results:

 

Battery Test: Charge Required 11.16v Measured 500 CCA, Rated 540 CCA Temp 58 degrees

Battery not totally fried. Did they charge it before testing? First Guess: No.

 

Starter Test: Low Cranking Amps Voltage 10.75V, Amps 0.2A, Time 6.00S

"Starter amp draw is low with ok starter voltage, check starter circuit for loose, worn or corroded wiring"

If the starter is drawing .2 amps, it will not start the engine. I'd have expected 100+ amps. The old Big Block engines would pull 200--225 amps. Two tenths of an amp means they screwed the pooch when testing your vehicle.

 

Charging System Test: No Voltage. No load 11.69V 0.0A, Loaded 11.69V 0.0A

Alternator is almost certainly fried.

 

While looking at alternators, is there anyone with a review of this one:

http://www.amazon.com/gp/product/B004J0WE92/ref=ox_sc_act_title_1?ie=UTF8&smid=ASQHPNXXVKB77

"NEW" almost certainly means "Made In China" junk. Verify country of origin (COO) before purchase.

Edited November 20, 2012 by Schurkey

[JimMadsen]

Nope they did not charge the battery, they followed me out to the parking lot. I didn't stop at my usual store, which is an autozone. Tomorrow I will pull the alternator and get it in for a load test. The results of that will either have me putting it back on or buying a alternator inside the store. One that I know I can bring back in if there is any problems. After the alternator is fixed / ruled out, I will focus on the battery.

 

Is pulling the alternator and getting a load test something I can do in their parking lot without it taking too much time? Obviously I cannot drive it once the alternator is out and the removal looks pretty well straight forward with no special tools. I imagine I can have it out in 10 minutes or so, but how long for them to test it? I already have printed out step by step directions for the removal.

 

I will verify COO on any part I buy at the store as well, thank you. Some research on that company showed they have had trademark suits brought against them.

 

Real quick on the battery, is there any trick to moving the tank out of the way? Or just undue the snaps and bolt and lift it clear? If I can, I may bring in the battery at the same time to have that tested on the bench (and charged at the same time.)

[Garrett Powered]

just go buy a charger

[JimMadsen]

I had issues trying to remove the alternator to get it tested yesterday and ran short of time. I got all the bolts off but the thing did not want to lift clear. I got the lower one with the free nut that you have to contort to get at, the upper one with the arm leading to the engine, and I pulled off the power steering plastic block and attacked the bolt under that. Now it appears to be only attached to the support arm to the engine from the rear of the alternator. I say appears because I could be wrong (and probably am) on that. I was able to get it to rock back and forth but not lift off. I was hoping to just pull the support arm right up with it.

 

As I said, I ran out of time so I put it all back together. Strangely my volt meter in the outlet (yes I know) jumped right up to 14.2 in idle. That lasted for the drive to work and is now back to where it was. I also have the whine again. And my battery is anywhere from 11.9-12.2 volts. It is being pulled and tested (along with the alternator since I will have all day) tomorrow.

 

I was able to plug the car into a computer and I have a P1671 error. What little I can find off the slip they gave me, and a google search, it is electrical. I want to rule out the battery and alternator because one, the battery may be dying anyways, and two I still keep thinking about that belt and the alternator is related to its proper function. The alternator is still getting up to 14.2+ with the RPMs above 1250 or so. A test will tell me whether it is working or not obviously.

 

For the whine, I came across the following after a google search for serpentine belt whine:

 

"When your belt displays any of the following:

-squeals when accelerating.

-chirps constantly

-squeals constantly

-squeals when wet or moist outside

-squeals when cold

-or any combination of the above.

 

The belt must be replaced, but wait... If you replace the belt it may stop for a while but then the noise comes back. This is because the old belt was slipping and has polished the pulleys or "glazed" them. So before you replace that noisy belt scrub all of the pulleys well with a scotch brite pad, or a good wire brush to remove the glaze and rough up the surface. Clean them off with brake cleaner afterward. Belts work by friction so if the surface is polished too much the belt will slip. If you have already put on a new belt and it is making noise, -sorry you must buy a new one again. Slipping on the pulleys will glaze a new belt fast which ruins it. Some people say you can apply brake cleaner etc to a new belt to fix it but that may not work well. If it slips it will just mess up your newly cleaned pulleys and you will have to scrub them up all over again. So do the job right and rough up the pulleys AND replace the belt at the same time."

 

I did have it replaced just a few weeks ago, what are the chances that the mechanic didn't clean the pulleys? Is this even accurate or is it just your usual internet trash. If it is accurate, how can I tell if my whine problem comes from this. It may also, if true, explain the alternator if it is slipping on the pulley and the alternator is not getting up to enough speed to provide voltage. Also if this is the case, how can you tell if the new belt is bad as described above? I want to be able to bring it to the garage and try to get my money back.

 

If this sounds legit, and since I will have the belt off anyways, I will clean it tomorrow.

 

What do you guys think?

[Garrett Powered]

sounds like you didn't charge the battery. hilarious!

[JimMadsen]

Thank you for your helpful insight. I do not have a battery charger and my 30 mile commute (mostly highway) should have charged the battery if that was the issue. But never fear, it will be tested and charged up in the morning when I have enough light to see what parts I need to remove to get the entire thing out.

 

But following your line of reasoning, would a low battery cause a belt whine or the alternator not to charge at low RPMs? I really do not know and am asking a serious question based upon your answer.

Edited November 22, 2012 by JimMadsen

[Garrett Powered]

a lot of older GM's and newer need an extra boost sometimes during bad weather you use more wipers, lights, heater. hot weather, same thing A/C, radiator fan motor, heat takes it's toll. it is a VERY good idea to have a charger at your disposal.

 

also a jumper pack. I do not have one of those, but I have a charger is a schumacher SE4020 like this: http://www.acehardware.com/product/index.jsp?productId=1296399&cagpspn=pla

 

 

 

but you could get a counter top one to save some space or some money. I love mine

[JimMadsen]

You do make a good point. Once I am sure the problems are fixed, I will look into a charger

[Garrett Powered]

?

 

I was suggesting it as a beginning of a solution. but if you insist on not fixing it immediately, then do the opposite I guess.

 

sorry but the way you are going about this is illogical.

[JimMadsen]

well if you insist.....

 

Should I just pull the battery, take it to autozone, have them charge it and test it and then look at other things? That at least won't cost anything. I don't see where a low batt would cause all of the problems, rather I think it is an end result, but it sounds like you know much more than I so I will give that a shot.

 

And yup, I will get a charger because I do realize that it is good to have lying around. Any opinion on the plug in dash ones? Thinking about one that my wife could use if needed.

[Garrett Powered]

anything is better than nothing. might I suggest a jumper pack for throwing in the trunk for emergencies?

[RobertISaar]

Any opinion on the plug in dash ones? Thinking about one that my wife could use if needed.

 

anything is better than nothing. might I suggest a jumper pack for throwing in the trunk for emergencies?

 

actually, i've combined the two....

 

my jumper pack is charged via it's charger, which is connected via a lighter plug to the car.... jumper is limited to supplying 5 amps through it's socket before tripping it's breaker.

 

it's not going to charge the battery quickly(charges at a little under 1 amp), but it will keep it nice and fully charged during the winter and long periods of non-use. just have to run a cable through the door if you place it all inside the cabin, rather than under the hood.

[Garrett Powered]

I still believe the jumper packs are just a luxury. I would place my funds on a charger if I were you.

[JimMadsen]

The battery is charging up, but I went back to square one and pulled the tensioner off and listened to it close to my ear. It spun freely so I did not think to look further. There was a faint screech to it when spun. I ended up replacing the tensioner (didn't cost much more than just the pulley / bearing.) The alternator went right up to 14.2 in idle and maintained that. I borrowed a charger from my dad and have that on the battery. I will go for a test drive later to see if the alternator output maintains.

 

I am thinking that the tensioner was failing, albeit slightly, causing slippage on the belt. Then in lower RPMs the alternator wasn't getting spun enough or consistently enough to output what it should. While having the belt off again, I listened more closely to the other pulleys. They all spin freely but I noted a slight screech to the ac clutch pulley. That will have to be replaced obviously. There is still a whine but much reduced. I am thinking I heard it because of the ac clutch pulley and the fact the hood was open. That and I was listening for it.

 

How hard is it to replace the pulley? Is it a bolt on-off like the tensioner? Can I ignore it for now? It does spin freely and being colder out, I am not using the ac.

 

I will test drive in a bit and see how the battery and alternator do at that point.

 

Thanks again all

[Schurkey]

The battery is charging up, but I went back to square one and pulled the tensioner off and listened to it close to my ear. It spun freely so I did not think to look further. There was a faint screech to it when spun. I ended up replacing the tensioner (didn't cost much more than just the pulley / bearing.) The alternator went right up to 14.2 in idle and maintained that. I borrowed a charger from my dad and have that on the battery. I will go for a test drive later to see if the alternator output maintains.

 

I am thinking that the tensioner was failing, albeit slightly, causing slippage on the belt. Then in lower RPMs the alternator wasn't getting spun enough or consistently enough to output what it should.

Interesting and very unexpected. If the belt was slipping that badly, it's ruined. You need a new belt. I've seen pulleys ruined by belt slippage. Check them as well.

 

While having the belt off again, I listened more closely to the other pulleys. They all spin freely but I noted a slight screech to the ac clutch pulley. That will have to be replaced obviously. There is still a whine but much reduced. I am thinking I heard it because of the ac clutch pulley and the fact the hood was open. That and I was listening for it.

 

How hard is it to replace the pulley? Is it a bolt on-off like the tensioner? Can I ignore it for now? It does spin freely and being colder out, I am not using the ac.

The A/C bearing is much more difficult to replace than the tensioner. Be sure the BEARING is noisy, not the front compressor seal or the clutch plate. If the pulley spins without roughness or free-play, the bearing is probably still serviceable. The bearing only rotates when the A/C is NOT engaged, when the A/C is functioning, the whole bearing spins with the pulley/compressor shaft. A failing bearing therefore can make noise with the A/C OFF, but be silent when the A/C is running.