cypermethrin Posted February 4, 2012 Share Posted February 4, 2012 This mormomg i was all ready to change the PAS and water pump on my 300tdi. But like everything it was not as simple as that. Turned the key starter motor threw solenoid, turned over but no fire. took key out and the starter eas still tring to turn the engine. Ended with burning smell from battery. The starter motor was shot the braided feed from the solenoid to the starter had burnt through. So off I went 30 mile round trip to get a new one. Fitted it, reconnected battery fizz and a bang it was toast too without even turning a key. I think ir mst have shorted out on the hoysing.... New unit defiantely dead Result a very cold and now thououghly disgruntled LR owner. With no way of fixing it til Monday... The old starter was about a year old and a Velco unit. It certainly took a big load to burn through the braided coonector betw the solenoud and starter..... What do yiu think was the cause of all this ? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 4, 2012 Share Posted February 4, 2012 Could be the ignition switch. If you get loose connectors in there, the starter keeps on spinning even if you remove the key and you have to be quick to disconnect the battery. I had this happen on my last car - nearly set fire to the vehicle by the time I cut the battery off. Les. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 4, 2012 Author Share Posted February 4, 2012 Hi Les, thats what i thought but the ignition barrel is also about 1 yr old. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 4, 2012 Author Share Posted February 4, 2012 Would a faulty relay starter be the cause ? Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted February 4, 2012 Share Posted February 4, 2012 would have thought the relay would have popped before the starter. does sound like a short or a faulty new starter? Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 4, 2012 Author Share Posted February 4, 2012 The only thing that makes sense to me is that altough starting fine yesterday afternoon - the PAS pump bearing noise I was going to fix this morning turned out to be the alternator bearings and it hasnt been charging the battery. This may explain the weak cranking - but not the continuation of the cranking once the key had ben removed Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted February 5, 2012 Share Posted February 5, 2012 sound like a battery fault low battery voltage high current might have jammed ur starter relay on due to burnt contact tips and as soon as u fitted the new starter and connected the battery tried to start and fried the new starter due to massive current. have seen starters burnt out like this but usualy not instantly like you discribed takes a few times then goes. is the starter system ok... apart from the motor. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 5, 2012 Author Share Posted February 5, 2012 The ignition lights and glow plugs all still work As do the other electrical stuff like lights, indicators wipers etc all ok So apart from toasting the starter motor and solenoid the rest looks to be ok Will hopefully be able to test the battery in mates 90 today..... To check its not boiled So the plan is to get another new starter, new ignition switch to be on the safe side and try again Am i missing somethimg? Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 5, 2012 Author Share Posted February 5, 2012 Well....... Its definately not the battery as it starts my mates 90 Also checked the ignition switch and relay .... The exciter wire to the solenoid gets a consistent 12v when key is turned to crank position The fly wheel is freely rotating when rocking the truck in gear Which leaves me at a loss as to why the problem arose...... Could it have been the -10 C freezing the starter solenoid in the energized position? Could it be the works or demons ? So the plan is to get another new start motor tomorrow and try again...... And if it continues to crank without the key in the ignition the plan to to whip out the starter relay A complete weekend lost..... Quote Link to comment Share on other sites More sharing options...
Mutley Posted February 5, 2012 Share Posted February 5, 2012 Me I wouldn't be throwing another starter motor at it until I have found SOME thing! Motors unlike animals don't get over an illness!,,,,,,,,So I wouldn't spend money till I at least found something out of the ordinary Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 5, 2012 Author Share Posted February 5, 2012 I agree - but I am struggling to know what to do next ...... the thing I do know is the 2nd new starter motor did short out as the constant live feed to the solenoid fowled against the outer casing of the solenoid where there was a metal stud - and it blew the contact. So that one is down to me. But why the orginal and first starter burnt out and continued to crank after removing the key )leaning tpo it burning out the brading feed bwetween the solenoid and the starter) remains a mystery Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted February 5, 2012 Share Posted February 5, 2012 sounds like the original starter welded the solenoid contact tips together . as the feed side for the starter has a constant +12 from the battery even with the key out it would continue to crank until the battery was disconnected. this could be down to the motor armature or brushes being worn or burnt drawing a high current through the solenoid. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 5, 2012 Author Share Posted February 5, 2012 I took the orginal starter to piece tonight.... Its about a year old Apart from the burning thro of the braided connector between the solenoid and starter it look fine. solenoid plunger nice and clean. No welding of connectors everything freely moving. Came across this thread below which describes a Merc drive going thro 3 starter in 5 days..... Turned out to be water getting into engine through via coolant system. Basically water was stopping the engine turning over. http://www.mbclub.co.uk/forums/engine/110548-starter-motor-keeps-burning-out.html I really hope this is not whats going on with mine....... I know i have a small water lead via the P gasket but nothing major. No mayo in the oil cap etc But i have an uneasy feeling that this might be it...... Although it does not account for the slow cranking after the ket was removed Am i worrying unecessarily? Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted February 5, 2012 Share Posted February 5, 2012 get a spanner or socket onto the crank pulley nut if te engine turns over freely it will be fine. Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted February 5, 2012 Share Posted February 5, 2012 to be completly sure u could remove the rocker cover and check for bent valves or water sitting in the head. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 5, 2012 Author Share Posted February 5, 2012 We made the fly wheel move by rocking so its not siezed solid. Surely there is enough inertia from the starter motor to crank.... Oh well fingers crossed its nit the worst case scenario Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted February 5, 2012 Share Posted February 5, 2012 the engine might not sieze up if there is water inside a cylinder it would jam up when the cylinder tried to compress the water as water does not compress it stops the engine dead or bends valves buckles heads or worse to releave the pressure. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 8, 2012 Author Share Posted February 8, 2012 Update : engine can be turned over by hand without any problem; all earths checked, ignition etc all fine. New starter motor fitted, turned over, fired and started first time on the button ! So - I got to thinking as to why the orginal starter burnt through. Should the solenoid engage and disengage independently of the connection betweent the solenoid and the starter. My small brain tells me a solenoid is only a mechnaical switch and once energised it 1/ trows the dolly out to engage with the flywheel and 2/ completes the circuit to start the starter motor. What I found on the bench test was that it would only do 1/ and 2/ if the braided connection between starter and solenoid was made. And without this connection the dolly did not move at all. Is this how it should operate ? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 8, 2012 Share Posted February 8, 2012 The solenoid does 2-things almost simultaneously. When you turn the key - the piston inside the solenoid flies fowards and engages the started dog with the flywheel. At the end of it's travel the piston also connects the battery main live cable to the starter motor itself, which then spins the engine. Les, Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted February 8, 2012 Author Share Posted February 8, 2012 (edited) Thanks Les So in theory there is no reason why, if the solenoid was not connected to the starter motor, that the solenoid would not engage the dog because as you say it does 2 things almost simultaneously and they are not dependent on each other ? BTW - looks as though I won't be needing your Disco 300TDi engine ! Edited February 8, 2012 by cypermethrin Quote Link to comment Share on other sites More sharing options...
HPLP Posted February 8, 2012 Share Posted February 8, 2012 I would be leaning towards the ignition switch. I had the same problem with a britpart one that I fitted that left the starter engaged. Did wonder why it felt sluggish! A push button start removed any risk of it happening again. H Quote Link to comment Share on other sites More sharing options...
DagdaNI Posted February 9, 2012 Share Posted February 9, 2012 Thanks Les So in theory there is no reason why, if the solenoid was not connected to the starter motor, that the solenoid would not engage the dog because as you say it does 2 things almost simultaneously and they are not dependent on each other ? BTW - looks as though I won't be needing your Disco 300TDi engine ! as long as your supplying its earth and lives, some times the teeth on the flywheel and on the starter get damaged and that can keep the starter engaged, but if your finding the main motor of the starter fine and the soleniod not working its unlikely its a ignition switch or damaged teeth as both of them wreck the main motor bearings or seize it, sounds like just a dud solenoid Quote Link to comment Share on other sites More sharing options...
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