alternator change
Discussion
Hi tested my battery 12.7v
started car 13.2v
heater lights stereo 12.5v
so looks like i need to change my alternator
my question is what is the best way to change remove inlet manifolds and fuel rail as one or move my aircon compresser and pull it out through the front
hopefully this explains why car would not start after filling with fuel 4 times if left for 20-30 mins would start or if used my jump pack would fire straight up
many thanks
started car 13.2v
heater lights stereo 12.5v
so looks like i need to change my alternator
my question is what is the best way to change remove inlet manifolds and fuel rail as one or move my aircon compresser and pull it out through the front
hopefully this explains why car would not start after filling with fuel 4 times if left for 20-30 mins would start or if used my jump pack would fire straight up
many thanks
Hold your horses - nip down to your local tyre and battery place, one you trust, and get the battery tested on their proper battery testing machine. You may well be right about the alternator, but a duff battery could be causing the same issues - and they could test your alternator's output at the same time. They will so love seeing a Cerbera I doubt they will "charge" much (see what i did there? 
)
)cshaw4200 said:
Sorry forgot to mention it is a 4.2
If you do need to change it, its much easier to remove the inlet manifolds. There are a few posts here how to remove them.The key is to ensure you slide out the aluminium spacers (two on each side) between the fuel rail and the rocker covers as these can fall down into the cylinder heads (then its heads off time !!!) you can leave the air boxes attached if needed.
When i did my alternator i also changed the inlet manifold heat sheilds and O rings as they were pretty shot along with a new belt for the alternator.
Good luck and i hope its just a duff battery.
Matt
chibbard said:
You have checked/changed the big fuse if necessary FIRST haven't you !!!!
+1 - sorry I forgot to mention that.get your multimeter out and with the ignition on and engine off see what voltage you have at the back of the alternator. If 12.7-13.7 volts, then your fuse is fine.
The readings you got were taken at idle I believe? If so, the alternator will not be charging until the engine rpm is nearer to or above 1,000 rpm.
I had similar symptoms and thought I needed a new alternator. If you have someone hold the revs at around 1,200 rpm and take the readings again, I think you will find they are now good. In my case I adjusted the small screw on the driver's side throttle stop to raise the idle revs to an indicated 1,000 rpm and problem solved.
The likely problem is that your battery is either not being charged due to a lot of engine idling causing no charge or the battery itself has lost its performance so unable to provide good cranking amps.
I had similar symptoms and thought I needed a new alternator. If you have someone hold the revs at around 1,200 rpm and take the readings again, I think you will find they are now good. In my case I adjusted the small screw on the driver's side throttle stop to raise the idle revs to an indicated 1,000 rpm and problem solved.
The likely problem is that your battery is either not being charged due to a lot of engine idling causing no charge or the battery itself has lost its performance so unable to provide good cranking amps.
cshaw4200 said:
Hi i can update car switched of battery 12.7
Voltage at alternator 12.7
Started car 13.4 more revs 13.9
Lights ,stereo,heater; revs 13.9
Hopefully by those readings my alternator is ok but my battery is not thanks for all the advice
Nail on the head - well diagnosed.Voltage at alternator 12.7
Started car 13.4 more revs 13.9
Lights ,stereo,heater; revs 13.9
Hopefully by those readings my alternator is ok but my battery is not thanks for all the advice
As the next poster says, you could happily waste a half hour at a tyre and battery independent who you trust, having your battery tested properly with their battery tester.
After two months off the road and an engine change, my battery was sluggish starting the car, which i put down to the different engine. It was only when I noticed acid on the carpet next to the battery that I thought I had better get it checked. The car started ok-ish, I got down there, they did all sorts of multimeter tests, got out their big battery tester, which said it was ok but was basically failing. I bit the bullet (which hadn't got acid on it fortunately) and said change it.
They then supplied and fitted (a right faff on a Chimaera) a brand new quality Exide battery of the correct orientation (it has to be the correct way round in the box so that the positive and negative terminals are the right sides, and their own guide had it listed wrongly), and the car immediately started as if the engine was a 500 cc, not 5000 cc. And the cost? £7 more than the battery would have cost me at the cheapest internet supplier. Bargain.
Supateg said:
The battery voltage is not that bad,
Best to have it load tested at a garage, maybe a fancy de sulphating charger will improve it.
A battery has 6 cells each producing 2.1 volts = 12.6 volts. This is the minimum you ideally need so 12.7 is getting close.Best to have it load tested at a garage, maybe a fancy de sulphating charger will improve it.
No need for trips to a fast fit garage for a mis-diagnosis. DIY is the answer!
Take reading with everything off. In this case 12.7 volts.
Switch headlights on and wait until voltage reading is at 12 volts or less. Switch lights off.
Keep meter on the battery and watch the recovery rate. A good battery will recover at roughly 0.1 volts around every 2 secs until it gets up to a min of 12.6 volts.
If the battery shows no sign of recovering then it is stuffed and nothing will get it back to proper cranking performance. Remember that when you drive to a garage you have just given the battery a good dose of voltage so the load test often does not show up a fault.
The only proper way to check a battery is by the recovery method. Trust me, I'm a gynaecologist
N7GTX said:
QBee said:
If a gynaecologist is a man who is good with battery powered devices, then i would take his advice.....I assume all his tests are done with the engine switched off? Or ON?
Engine off. Everything off. Now lay on the couch my dear.N7GTX said:
A battery has 6 cells each producing 2.1 volts = 12.6 volts. This is the minimum you ideally need so 12.7 is getting close.
No need for trips to a fast fit garage for a mis-diagnosis. DIY is the answer!
Take reading with everything off. In this case 12.7 volts.
Switch headlights on and wait until voltage reading is at 12 volts or less. Switch lights off.
Keep meter on the battery and watch the recovery rate. A good battery will recover at roughly 0.1 volts around every 2 secs until it gets up to a min of 12.6 volts.
If the battery shows no sign of recovering then it is stuffed and nothing will get it back to proper cranking performance. Remember that when you drive to a garage you have just given the battery a good dose of voltage so the load test often does not show up a fault.
The only proper way to check a battery is by the recovery method. Trust me, I'm a gynaecologist
Were you the chap I was talking to at Lotherton Hall, Cars in the park? You are restoring a Cerb?No need for trips to a fast fit garage for a mis-diagnosis. DIY is the answer!
Take reading with everything off. In this case 12.7 volts.
Switch headlights on and wait until voltage reading is at 12 volts or less. Switch lights off.
Keep meter on the battery and watch the recovery rate. A good battery will recover at roughly 0.1 volts around every 2 secs until it gets up to a min of 12.6 volts.
If the battery shows no sign of recovering then it is stuffed and nothing will get it back to proper cranking performance. Remember that when you drive to a garage you have just given the battery a good dose of voltage so the load test often does not show up a fault.
The only proper way to check a battery is by the recovery method. Trust me, I'm a gynaecologist
-Craig
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