2007 aygo dies when alternator is connected

[niceone]

34 minutes ago, flash22 said:

Change the alternator for another, will it run with the thin red disconnected

I tried both things and it didn't help. Even at 2000 rpm it still dies, I can hear like a slowing down whistle sound when connecting the alternator at that speed. You need like 3000 rmp for it to stay alive.

[Mooly]

I've no answers to this but find it an intriguing issue...

Could an alternator load an engine so much (loaded electrically rather than mechanical defect) that it could stall it? I would have thought it would be able to spin it no matter what the loading.

(just seen your new post as I'm typing)

Off the wall thoughts... 

Crazy as this might sound. Turn your headlights on and also put them on full beam and then start the engine. Put the lights on FIRST and it will only be of use if they are filament bulbs and not LED's. The idea is to load the alternator heavily from the get go.

Thinking behind that is possibility of an overvolts situation and something is cutting out... is there overvolts protection anywhere such that the ECU can stop the engine. Fuel relay. Random thoughts.

(your reply kind of casts doubt on what I just typed... however...) 

 

 

 

[niceone]

18 minutes ago, Mooly said:

I've no answers to this but find it an intriguing issue...

Could an alternator load an engine so much (loaded electrically rather than mechanical defect) that it could stall it? I would have thought it would be able to spin it no matter what the loading.

(just seen your new post as I'm typing)

Off the wall thoughts... 

Crazy as this might sound. Turn your headlights on and also put them on full beam and then start the engine. Put the lights on FIRST and it will only be of use if they are filament bulbs and not LED's. The idea is to load the alternator heavily from the get go.

Thinking behind that is possibility of an overvolts situation and something is cutting out... is there overvolts protection anywhere such that the ECU can stop the engine. Fuel relay. Random thoughts.

(your reply kind of casts doubt on what I just typed... however...) 

 

 

 

Thanks for the input, didn't wont though.

[Mooly]

OK, it was worth a try.

It is a very strange problem to me, one I can't just make head or tail of at the moment.

[flash22]

Pull the starter motor and bench test it, it's the only thing I can think of it being at this point - high electrical load and will cause mechanical drag if it doesn't disengage - the alternator is a symptom

Any change if you pump the clutch ?

Did you disconnect any wiring from the fuse box ?

[niceone]

14 hours ago, flash22 said:

Pull the starter motor and bench test it, it's the only thing I can think of it being at this point - high electrical load and will cause mechanical drag if it doesn't disengage - the alternator is a symptom

Any change if you pump the clutch ?

Did you disconnect any wiring from the fuse box ?

What do you mean by bench test the starter motor? And no to the other questions.

[Mooly]

You've tried an alternator (twice) and also say the fault is apparent whether or not the belt is fitted.

You also say it runs OK when connected to another cars charging system. The only difference now is you have a known good Battery in parallel with yours.

Are you looking to hard for a problem here?

Could it be something as simple as a duff Battery, one that is so down on capacity it behaves like one of just a few Ah capacity?

[niceone]

15 hours ago, flash22 said:

Pull the starter motor and bench test it, it's the only thing I can think of it being at this point - high electrical load and will cause mechanical drag if it doesn't disengage - the alternator is a symptom

Any change if you pump the clutch ?

Did you disconnect any wiring from the fuse box ?

I tried to disconnect the starter motor when running and same happens.

[flash22]

12 minutes ago, Mooly said:

You've tried an alternator (twice) and also say the fault is apparent whether or not the belt is fitted.

You also say it runs OK when connected to another cars charging system. The only difference now is you have a known good battery in parallel with yours.

Are you looking to hard for a problem here?

Could it be something as simple as a duff battery, one that is so down on capacity it behaves like one of just a few Ah capacity?

Been down this rabbit hole - so much has been done, it has turned into a mess

the car cranks and starts, alternator is a red herring, no codes, so it's either electrical or mechanical

if the engine had enough torque, it would overcome the load on it

 

I would be checking the compression

[niceone]

26 minutes ago, Mooly said:

You've tried an alternator (twice) and also say the fault is apparent whether or not the belt is fitted.

You also say it runs OK when connected to another cars charging system. The only difference now is you have a known good battery in parallel with yours.

Are you looking to hard for a problem here?

Could it be something as simple as a duff battery, one that is so down on capacity it behaves like one of just a few Ah capacity?

No no, actually the car runs with belt off. Tried another cats Battery and didn't help.

[flash22]

When you changed the crank did you fit new shells in the mains, big ends and thrusts ?

[niceone]

Not new but in good condition. I got 120 140 and 120 psi from 1st cylinder to the last. It increased to 160 psi with oil, so guess the issue now lies in the rings or cylinders.

[flash22]

The shells wear to the crank and also the block the mains are line bored, no 2 blocks are the same, the thrusts are also specific to the block and crank you have some running clearances, but you can't mix and match 5–10 thou is enough for a crank to bind up or loose oil pressure or not get any at all

did you stager the rings correctly or hone the bores - the lack of oil can warp the bore and cause the rods to egg out, it's down on psi it should be 180-210 psi and within 10% across the 3 cylinders (11:1 compression ratio) you may have bent a valve(s) also

[niceone]

41 minutes ago, flash22 said:

The shells wear to the crank and also the block the mains are line bored, no 2 blocks are the same, the thrusts are also specific to the block and crank you have some running clearances, but you can't mix and match 5–10 thou is enough for a crank to bind up or loose oil pressure or not get any at all

did you stager the rings correctly or hone the bores - the lack of oil can warp the bore and cause the rods to egg out, it's down on psi it should be 180-210 psi and within 10% across the 3 cylinders (11:1 compression ratio) you may have bent a valve(s) also

I didnt mention it but I had new bores put in since the last ones were worn out and I did stager the rings so very weird. The valves were also checked and cut by a pro.

[niceone]

17 hours ago, flash22 said:

The shells wear to the crank and also the block the mains are line bored, no 2 blocks are the same, the thrusts are also specific to the block and crank you have some running clearances, but you can't mix and match 5–10 thou is enough for a crank to bind up or loose oil pressure or not get any at all

did you stager the rings correctly or hone the bores - the lack of oil can warp the bore and cause the rods to egg out, it's down on psi it should be 180-210 psi and within 10% across the 3 cylinders (11:1 compression ratio) you may have bent a valve(s) also

Removed the head, all valves seem to seat flush, how do you check if your valves are bent? The pistons and bores seem pretty fine, I think its the rings.

[flash22]

If you have the cams out, the valve will sit flush, fill the pockets up with liquid (petrol, diesel or paraffin) if it leaks past you know there is an issue, if it stays the same all is good (leave it for 5-10 min's)

[niceone]

2 hours ago, flash22 said:

If you have the cams out, the valve will sit flush, fill the pockets up with liquid (petrol, diesel or paraffin) if it leaks past you know there is an issue, if it stays the same all is good (leave it for 5-10 min's)

The level did decrease, but cant it just be evaporation? I compated the rings to a set of new ones and they looked kinda identical.

[flash22]

Are the old rings sharp, you may have washed the bores is so they need a hone

did all 3 pockets drain the same ?

[niceone]

4 minutes ago, flash22 said:

Are the old rings sharp, you may have washed the bores is so they need a hone

did all 3 pockets drain the same ?

Dont know what you mean by washed but the bores still have honing marks. Idk whether the rings are sharp. All of the pocket drained the same, I'm gonna clean the valve surface clean and check than if it leaks.

[niceone]

43 minutes ago, flash22 said:

Are the old rings sharp, you may have washed the bores is so they need a hone

did all 3 pockets drain the same ?

Now when all clean, I saw a single exhaust valve in each cylinder and 1st and 3rd cylinder intake valve leak, but very slightly. I mean could these small leaks be my issue?

[flash22]

You can lose pressure, that would explain why it's down on compression on 1 and 3

washing the bores is when the cylinder gets too wet with fuel and/or oil it smooth over the bore and the rings don't seal correctly, a light hone will help with this