300tdi auto non starter w/massive current drain

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biolandy said:
Don't get despondent,this should be quite easy to sort out-

I am beginning to think the man needs to be SURE his EARTH CABLE CONNECTIONS are sound, especially between the egnine and chassis, ands from chassis to battery - negative.


But I go with the man who says the battery is goosed.

CharlesY
Click to expand...
 
Yup,that is on the known-shagged battery,just for demo purposes.Similar thing happens with new batteries,I have 3 to play with.Had glow plugs disconnected before.Checked them all as they were fitted,all good.Tried without the control relay.When a good battery is fitted it turns the engine over very slowly then the battery dies as there is a massive current drain somewhere that I cant find.

So,fit spare starter and try direct supply.My jump leads are V heavy duty....from my HGV days.

Try again tomorrow ! The car is over 20 miles away,stuck in the bay I need to get a truck into for welding at the weekend.....no pressure then! I get about 2 hours in the afternoon to play with this,so wish me luck.

And thanks everyone for sticking with me,any more for any more ?
 
shocker said:
So,fit spare starter and try direct supply.My jump leads are V heavy duty....from my HGV days.

Try again tomorrow ! The car is over 20 miles away,stuck in the bay I need to get a truck into for welding at the weekend.....no pressure then! I get about 2 hours in the afternoon to play with this,so wish me luck.

And thanks everyone for sticking with me,any more for any more ?
Click to expand...


Could you not tow it home anyway and work on it there?

Have you been off-roading and filled the bell-housing with mud?

CharlesY
 
So,even with a new battery and a jump start with heavy cables,as soon as the ignition is on there is a massive power drain.Wheres it going?Happens even with alternator and starter disconnected.

Engine will turn over slightly which may be due to something seizing,or may be due to lack of power going to starter....direct power to starter will show that one.But if it proves NOT to be a sieze then Im still left with the disappearing power.

I started on earth clean up yesterday when the light went.I have had to put in extra battery and engine earths on discos before....I suppose that I will have to do it again.If oil is NOT a conductor then maybe oil in the earth points may be a factor.
 
I dont off road this one,its my road car.There is a persistant oil leak from the back crankshaft seal though.As for getting it home that would be a propshafts off job,would it not?I hate doing that!The only place for it is back in the field....at least the mud is soft!
 
Are you sure we don't have a silly here,battery is on correct way round,(-ve is ground or earth)-glowplug power lead is not grounded somewhere-starter lead is not chaffed and grounding somewhere-or similar
 
I dont get this one at all.

You have a power drain big enough to stop it turning over at the instant the switch is turned to position 1???

I am pretty sure that the only cables in use at that position are too small to draw that much power without burning up instantly.

Can you measure the voltage AT THE BATTERY TERMINALS while turning on to pos 1, i know its gonna be a bit fiddly as you need to be in two places at once.

If the battery reads less than 12v before trying, dont bother, its flat.
If the battery reads 12+ when switched on, its got to be a bad earth sapping the power.
If the battery reads 12 and dropping, switch off and physically check all the wires from the battery in towards the fusebox/relays etc. It can only be a dead short and will likely burn up or be hot to touch.

Dave
 
No obvious shorts that I can find and no hot wires....so far.....battery(x4,the one on there now buggered and the three tested good spares) connected the correct way and I have been measuring at the battery terminals the whole time.

What occurs to me now is to split up the battery positives....measure before and after connecting starter lead,then fusebox supply seperately.Then I will try removing main fuses one at a time.I will try at position one.And so on,also cleaning and making new earths.

God,I need to make a sodding list.Thanks everyone.
 
i missed that one, pull all the fuses first.

then measure voltage and test each one, one at a time, including a test with all removed.

that might at least highlight a circuit.

dave
 
Right,cleaned battery earth to chassis and put in extra battery earth to inner wing.

Tried meter testing battery at all ignition positions,each live cable in turn,starter out and disconnected.Good news is there seems to be now no massive current drop there.

Bad news is that when I fitted the spare ,tested starter and powered it with jump leads from a tested good battery,it struggled to turn the engine over once.At this point light stopped play.

I didnt get a chance to meter what the starter was pulling,but the engine seems to be unable to turn over though I can do it on the spanner.Maybe what I consider reasonable resistance is not,reasonable that is.

Bearing in mind that this all started with a blown head gasket and water in pots,whats going on here?The piston rise didnt indicate any damage there.Can the state of the head cause this?
 
Are the glow plugs in or out, if they're in try removing them and then cranking her over, this will remove any compression effects and if it wont turn there must be something seized or binding up.

If it does crank over then it points to the top end - valves, timing, rockers etc

water in the pots could have rusted up a bore or two, piston rings, just thinking out loud.

I'm really baffled with this one, at least its mechanical now not 'lectrics :)
 
You may not be able to get enough power down a jump lead on the starter direct,to spin the motor fast,unless the jump lead is bigger than the starter cable itself(resistance is very important in high current applications,and saps power) -which is unlikely.
Presumably there is no water left in the bores,we are not trying to compress water .
Have you tried spannering it over for at least two complete revs-no timing belt issues hopefully.
If you think you can now turn on the ignition and glow plugs with no massive current draw,I would reconnect the starter and try and start it,but with jump leads from another running engine attached-your battery may not be quite as lively as you think.
To understand the power of a good starter motor and battery,when I did my cam belt,I used a breaker bar and the starter motor to undo the crank nut-had the bar on blocks,under the disco-when I turned the key the front of the disco with me in it went up in the air at least 6 inches,maybe more.(could see over the top of next door's van!)
If you can turn it over by a spanner,a good starter motor will do it easily with a good battery
 
Thats what really gets me.....I know how powerful a starter is....how come its not turning this engine over when I can do it by hand? The engine was running after I did the head gasket,then the battery(s) died overnight and then it wouldnt start even with heavy jump leads from a fast running disco with a 100a alternator.Back to square one.How could anything in the head stop an engine from turning over?
 
shocker said:
Thats what really gets me.....I know how powerful a starter is....how come its not turning this engine over when I can do it by hand? The engine was running after I did the head gasket,then the battery(s) died overnight and then it wouldnt start even with heavy jump leads from a fast running disco with a 100a alternator.Back to square one.How could anything in the head stop an engine from turning over?
Click to expand...


There can only be a few reasons ...

1. duff starter motor

2. not enough CURRENT (lousy battery or poor connections or a SHORT CIRCUIT somewhere when the starter is energised).


and as for the final question "How could anything in the head stop an engine from turning over?" if a valve is reaching a piston, you can be sure that the engine will be VERY tight to turn past that point, and something will be broken or bent afterwards.

CharlesY
 
try daves suggestion of removing heater plugs, then turning it over. watch for
liquid comin from the cylinders. let us know how fast it turns over.

slow, goosed starter

ok, bad timing.

when i chack starters prior to fitting, i clamp in a vise and use jump leads to earth and pos on solenoid. actuate solenoid with wire from terminal to jup lead. when it spins up, i then rather crudely ram a lump of wood into the starter pinion to try and stop it, putting a bit of load onto it.
what i dont know with the 300 starter is- do they have a clutch in them as the v8 did?
being that the starter is turning fast, just the clutch slipping?
 
nrgserv said:
try daves suggestion of removing heater plugs, then turning it over. watch for
liquid comin from the cylinders. let us know how fast it turns over.

slow, goosed starter

what i dont know with the 300 starter is- do they have a clutch in them as the v8 did?
being that the starter is turning fast, just the clutch slipping?
Click to expand...


Most starters these days include a one-way clutch so that when the engine fires up it does not over-speed the starter motor.

The starter motor will probably include a reduction gear drive of 3 or 4 to one, and THEN it might take 30 or 40 revs of the starter to turn the engine once. The potential torque is enormous.

CharlesY
 
Yeah,but I can still turn it over and over and over by hand with no noticable difference between cylinders which I thought would rule out valves hitting pistons.

Next move try to make new earths for the starter and jump directly from a running vehicle with compression reduced.Im going to do injectors out as its an aircon car and No 1 glow is behind the compressor.

Update later.Thanks Everyone.By the way,all cables used are welding cable as heavy or heavier than fitted to disco.With properly crimped on ends.
 
Limited time today.loosened off the injector clamps and wiggled the injectors loose but not out.Linked up starter to running 98 300tdi with jump leads made of 16mm2 welding cable.Engine turned over at around 2 revs a second.leads smoking within half a minute,fireproof cable mind.Some spray coming out past injectors that I assumed was fuel.Couldnt see them properly or header tank from my position.No noise of valves or any head problems.

You know what?I think that was water spraying out past the injectors.Water is the only thing I have known to stop a starter dead,viz: you cannot compress it.So,head off and investigate gasket.The head was one I had bought new a couple of years ago and had on an engine for two weeks before I took the engine apart for bottom end problems.Maybe the head has warped with time.Maybe my torque wrench is shagged.They were new headbolts and mirror finishes on head and block,degreased immediately before fitting.

Anyone???
 
completely remove the injectors to get rid of all compression.
let us know how fast it turns like this.
lookin like it could be a head off job anyway.

still thread following, but am away from computer a bit now.
 
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