Battery problem? Or Alternator?

[Matrixx]

Just want to get the views of bros here before I get it to the workshop. Don't wish to go to one with no clues and end up paying more.

 

I'm driving a mazda 3 SP and recently I'm having the following problem, intermittently though:

 

1) When I start the car, everything seems ok. Idling is fine. I started to move off. When I come to the first stop, car starts to vibrate, RPM drops to about 400 (or maybe lower). I have a volt gauge in the car, and it shows the voltage drop to about 11V. Car vibrates and then stall.

2) Re-start the car again and move off, reach another stop, same thing happens.

3) Re-start and move the car by the road side. Off the car completely, wait for a while, start it again and then move off and everything seems ok till I reach my destination.

 

Observations:-

 

1) At "ACC ON", volt gauge shows 11.2V

2) Start the car, with everything off including aircon, voltage shows 12.8V

3) With aircon on, the voltage hovers around 12.8V thereabout

 

Any comments about what could possibly be the problem?

 

Thanks

[Kelvingoh45]

Spark plug, spark plug cable??? fuel injector?

[Pisces69]

Just want to get the views of bros here before I get it to the workshop. Don't wish to go to one with no clues and end up paying more.

 

I'm driving a mazda 3 SP and recently I'm having the following problem, intermittently though:

 

1) When I start the car, everything seems ok. Idling is fine. I started to move off. When I come to the first stop, car starts to vibrate, RPM drops to about 400 (or maybe lower). I have a volt gauge in the car, and it shows the voltage drop to about 11V. Car vibrates and then stall.

2) Re-start the car again and move off, reach another stop, same thing happens.

3) Re-start and move the car by the road side. Off the car completely, wait for a while, start it again and then move off and everything seems ok till I reach my destination.

 

Observations:-

 

1) At "ACC ON", volt gauge shows 11.2V

2) Start the car, with everything off including aircon, voltage shows 12.8V

3) With aircon on, the voltage hovers around 12.8V thereabout

 

Any comments about what could possibly be the problem?

 

Thanks

 

 

Chk yr battery terminals if tight n alternator belt.

 

Looks like cud b loose connection somewhere.

 

Go to a good battety shop n ty can chk if yr alternator or battery faulty.

 

Yr prob intterment which can b very hard to find fault. Hope it happen when ty checking.

[Watwheels]

If the engine can crank, start and run, the batt and alternator is fine. What is not fine is your history of your car's servicing. What was the last spark plug change and what plugs were used? How old is your car and what's the mileage? The symptoms you gave can be problem from the spark plugs, fuel injector or throttle body and the engine oil used can make a difference too. What is your engine oil level. Pls read the level in the morning or parked for at least 3-4hrs before you start the engine.

[Kb27]

It looks like your alternator is dead.

More specifically, the voltage regulator is dead.

It can't regulate voltage at 14V.

 

Try revving your engine and see if the voltage goes up and down together with the rpm.

Edited December 19, 2012 by Kb27

[Matrixx]

If the engine can crank, start and run, the batt and alternator is fine. What is not fine is your history of your car's servicing. What was the last spark plug change and what plugs were used? How old is your car and what's the mileage? The symptoms you gave can be problem from the spark plugs, fuel injector or throttle body and the engine oil used can make a difference too. What is your engine oil level. Pls read the level in the morning or parked for at least 3-4hrs before you start the engine.

 

 

I just did a spark plug change 2 days back. Denso Iridium. Thought it could be one of the causes too. The throttle body was cleaned by a workshop about 3 months back. Problem started only about a month ago. As for the engine oil, did a check in the morning and it was full.

[Matrixx]

It looks like your alternator is dead.

More specifically, the voltage regulator is dead.

It can't regulate voltage at 14V.

 

Try revving your engine and see if the voltage goes up and down together with the rpm.

 

 

No it doesn't really change. It just hovers thereabout 12.8V

[Matrixx]

Chk yr battery terminals if tight n alternator belt.

 

Looks like cud b loose connection somewhere.

 

Go to a good battety shop n ty can chk if yr alternator or battery faulty.

 

Yr prob intterment which can b very hard to find fault. Hope it happen when ty checking.

 

 

Ya, that's the problem. Intermittent. It doesn't always happens. Probably once every 2 days, and it always happens when start from cold. i.e. having parked there for a couple of hours already.

[Kb27]

No it doesn't really change. It just hovers thereabout 12.8V

 

12.8V is a tad too low, assuming the reading is correct.

It will not have enough voltage to charge the battery when all the electrical loads are turned on.

 

When you turn on headlights, aircon blowers, the voltage drops and you're using battery charge.

Since the battery can't handle continuously draining from it during idle, the rpm also drops and the engine stalled.

 

I would suggest you get a workshop to look at the alternator first.

[CinCin]

I just did a spark plug change 2 days back. Denso Iridium. Thought it could be one of the causes too. The throttle body was cleaned by a workshop about 3 months back. Problem started only about a month ago. As for the engine oil, did a check in the morning and it was full.

 

 

How abt gear oil ?

[Imanimo]

faulty idle control valve ?

[Meganut]

It looks like your alternator is dead.

More specifically, the voltage regulator is dead.

It can't regulate voltage at 14V.

 

Try revving your engine and see if the voltage goes up and down together with the rpm.

 

 

 

agree with this brother maybe the regulator is dying...

 

other possible cause for stalling is ignition coil aka spark plug coil... or fuel pump otw to dying, which might not be your case for now..

[Pisces69]

Ya, that's the problem. Intermittent. It doesn't always happens. Probably once every 2 days, and it always happens when start from cold. i.e. having parked there for a couple of hours already.

 

 

Cold......cud b yr air/fuel mix too lean which cause rpm drop n shudder?

 

Might b sensor prob. Better u send to good mech to troubleshoot.

 

 

[Subutai]

Did you encounter CEL on? If so, then a scangauge should be able to get the error code for diagnose.

[Bornno1]

check MAF sensor for idling problems, your low voltage is caused by low idling.

[Chucky2007]

Could be very dirty throttlebody. Ask yr workshop to clean it. Cost $30-50 in SG workshop. Anyway if its not the cause, but u ha e never clean it before, its good to have it cleaned as well

[Yeobh]

Chances one of the plug cable is not properly seating on the plug.The other possiblity is yr mech may have damage one of the plug cable while removing from the plug. It's very common for mech to pull the cable without a proper tool, resulting in fracturing the cable internal carbon fibre.

If your alternator is not performing normally yr ride can keep on going until the battery power drop to below 70% of it's capacity. Yrs is a intermittent problem while the engine is not warm up yet.

[Ninja]

Change spark plug & plug cable can liao.Confirm misfire case.