Weak cranking during cold startup

[Ahkeong]

Hi Bro,

 

Recently encountered weak cranking during cold startup. Initially thought weak battery but workshop tested that it has 100% charge. However, during the cranking, they tested that voltage changed from 12V to 6V. They serviced the starter motor but still the problem persist. Any bro here can advise what could be the real cause and appropriate measures to diagnose? Warm startup is okay only cold startup.

[Gendut]

Hi Bro,

 

Recently encountered weak cranking during cold startup. Initially thought weak battery but workshop tested that it has 100% charge. However, during the cranking, they tested that voltage changed from 12V to 6V. They serviced the starter motor but still the problem persist. Any bro here can advise what could be the real cause and appropriate measures to diagnose? Warm startup is okay only cold startup.

 

Qiuck assumption will be to suspect a short somewhere but that will exhibit some other symptoms too.

 

Maybe you can explain what did the shop do to determine 100% battery condition? Serviced starter motor? Again what did he service?

[Metalbone]

Hi Bro,

 

Recently encountered weak cranking during cold startup. Initially thought weak battery but workshop tested that it has 100% charge. However, during the cranking, they tested that voltage changed from 12V to 6V. They serviced the starter motor but still the problem persist. Any bro here can advise what could be the real cause and appropriate measures to diagnose? Warm startup is okay only cold startup.

 

How old is your battery?

[ER-3682]

Hi Bro,

 

Recently encountered weak cranking during cold startup. Initially thought weak battery but workshop tested that it has 100% charge. However, during the cranking, they tested that voltage changed from 12V to 6V. They serviced the starter motor but still the problem persist. Any bro here can advise what could be the real cause and appropriate measures to diagnose? Warm startup is okay only cold startup.

Maybe you can leave the car at the workshop overnight,let the mechanic start in the morning to find out the exact cause.?

[Yuan]

Hi Bro,

 

Recently encountered weak cranking during cold startup. Initially thought weak battery but workshop tested that it has 100% charge. However, during the cranking, they tested that voltage changed from 12V to 6V. They serviced the starter motor but still the problem persist. Any bro here can advise what could be the real cause and appropriate measures to diagnose? Warm startup is okay only cold startup.

 

Send to another workshop for second opinion.

 

Might be alternator issue.

[Yeobh]

When yr battery voltage drops to 9.5 volt during cranking, the batter need to be charged and the cranking test ( high discharge test) needs to be repeated. If the battery voltage drops just to 10 volt it is ok to use the battery if not replace the unit.

[Ahkeong]

Qiuck assumption will be to suspect a short somewhere but that will exhibit some other symptoms too.

 

Maybe you can explain what did the shop do to determine 100% battery condition? Serviced starter motor? Again what did he service?

 

Hi Bro,

 

They plugged in the battery tester before cranking and after cranking. For the starter motor, i followed to the other shopt that stripped the whole unit and rebuilt it.

[Ahkeong]

How old is your battery?

 

The battery is 3mths old only, just changed in feb 2010. Amaron 66DIN.

[Ahkeong]

Send to another workshop for second opinion.

 

Might be alternator issue.

 

 

Hi Bro,

 

I have considered this option but I have clarified with another friend that it is not likely as this problem only happens during cold startup. If alternator issue, even warm startup should have the same problem. However, my friend insist that the problem is still likely that battery itself cannot hold charge. I guess i have to go another workshop for second opinion. Thanks a lot for your advice.

 

 

 

[Pisces69]

Hi Bro,

 

I have considered this option but I have clarified with another friend that it is not likely as this problem only happens during cold startup. If alternator issue, even warm startup should have the same problem. However, my friend insist that the problem is still likely that battery itself cannot hold charge. I guess i have to go another workshop for second opinion. Thanks a lot for your advice.

=============

 

Ya possible that the battery cannot hold a charge. Strange as its only 3 months & Amaron is a good brand.

 

With engine off try switching on headlights & press horn. Does the lights go dim & the horn sound weak? Then u need to check if the alternator is charging properly.

 

Looks like likely these 2 things mainly. If both r OK, then u got to check other stuff like short-circuit or maybe loose connection at battery terminal or somewhere else.

 

[Limbat]

 

Most likely a weak or poor condition battery - if only 3months old check the agent for warranty

[Yuan]

Hi Bro,

 

I have considered this option but I have clarified with another friend that it is not likely as this problem only happens during cold startup. If alternator issue, even warm startup should have the same problem. However, my friend insist that the problem is still likely that battery itself cannot hold charge. I guess i have to go another workshop for second opinion. Thanks a lot for your advice.

 

Then it is advisable to check your battery, its terminals, and other related connections.

 

I have bad experience with workshops who changed my battery, telling me battery died already, only to discover later that it is the terminals that are dirty and just need to clean up the terminals and tighten the loose connections. Battery was then still usable.

[Watwheels]

If battery and starter are not the cause dan it could be other possibilities like air fuel mixture too lean/too rich(did you do any ecu tuning) or the presence of water in the engine's combustion chamber(head gasket leak coolant into the chamber). Or maybe it's just the spark plugs that need replacement.

 

[Gendut]

Hi Bro,

 

They plugged in the battery tester before cranking and after cranking. For the starter motor, i followed to the other shopt that stripped the whole unit and rebuilt it.

 

However, during the cranking, they tested that voltage changed from 12V to 6V.

 

Lets assume that your starter motor is ok since it was stripped and rebuilt.

 

If before cranking it is 12V is strange. To drop to 6V is even stranger. I shall also assume yr 6V reading is inaccurate. So what is left (after you've described other symptoms) is the fact that cold cranking is slow.

 

Without realy putting yr own hands on the car and the absence of other indications, thats very diff to diagnose. May I suggest you disconnect the aircon compressor clutch actuation during starting and see if it makes a difference. Forgot that the same symptoms would manifest.

 

Is yr aircon extraordinarily cold?

Edited May 16, 2010 by Gendut

[Ahkeong]

However, during the cranking, they tested that voltage changed from 12V to 6V.

 

Lets assume that your starter motor is ok since it was stripped and rebuilt.

 

If before cranking it is 12V is strange. To drop to 6V is even stranger. I shall also assume yr 6V reading is inaccurate. So what is left (after you've described other symptoms) is the fact that cold cranking is slow.

 

Without realy putting yr own hands on the car and the absence of other indications, thats very diff to diagnose. May I suggest you disconnect the aircon compressor clutch actuation during starting and see if it makes a difference.

 

Hi Bro,

 

The more exact symptom is that when I turn the key, in normal state, my defi meters will light up with the opening sequence but now, it is not lighting up. The feeling is like not enough power, then i crank the engine also like not enough power. I have to crank longer than usual to turn on the car.

 

 

[Jamesc]

Borrow another battery and put in your car and see if the symptoms persist.

 

If it cures it then its your battery, u can claim warranty.

 

If it persist then check your alternator, very likely its that.

[Pisces69]

Then it is advisable to check your battery, its terminals, and other related connections.

 

I have bad experience with workshops who changed my battery, telling me battery died already, only to discover later that it is the terminals that are dirty and just need to clean up the terminals and tighten the loose connections. Battery was then still usable.

===============

 

Its time to look for a new battery shop then.

 

[Yeobh]

I suspect the alternator is not rectifying 100% AC current to DC . Maybe a high percentage of AC current is entering the battery and causing short circuit within the 3 month's old battery plates.