How long will a diesel run with no alternator... a quandry?
Discussion
...AKA 'least worst way out of another Renault problem'
Daily snotter Laguna 2.2 has decided to break it's auxiliary belt crank pulley - typical harmonic damper failure with the belt track and body doing their own things. It's at home, I have the new pulley and belt but the centre bolt refuses to budge with big hand tools (and big hands). Have a mate who has the kit to move it but need to get the car the 30 miles there.
Belt still intact, I drove it (gingerly) home about 10 miles after the thing let go last night. Lots of ominous clattering (metal halves of pulley fretting together but no signs of peripheral damage anywhere and nothing being contacted that shouldn't be)
Options as I see them:
Buy a 'leccie rattle gun and hope that will move the bugger so I can sort at home (not convinced anything short of mega-bucks pro kit will stand a chance) - not attractive; I don't really need the tool and it will probably just go on the shelf with a load of other largely unused kit after failing to do the job. The money would be better invested elsewhere (different daily snotter perhaps).
Drive it (even more gingerly) to mate's workshop as is, stopping regularly to make sure the belt is hanging in there - if it lets go there's a good chance of damage to timing belt behind it and/or other soft components nearby. Belt seems pretty unscathed so far but I doubt much warning will be given.
Drive it (less gingerly but still cautiously) after cutting belt - much less chance of catastrophic damage but no PAS and no charging (hence title) - no idea whether a charged battery will see me 30 miles/an hour up the road if I keep everything I can off.
Discuss....
Yeah I could have it recovered but where's the fun in that?
Daily snotter Laguna 2.2 has decided to break it's auxiliary belt crank pulley - typical harmonic damper failure with the belt track and body doing their own things. It's at home, I have the new pulley and belt but the centre bolt refuses to budge with big hand tools (and big hands). Have a mate who has the kit to move it but need to get the car the 30 miles there.
Belt still intact, I drove it (gingerly) home about 10 miles after the thing let go last night. Lots of ominous clattering (metal halves of pulley fretting together but no signs of peripheral damage anywhere and nothing being contacted that shouldn't be)
Options as I see them:
Buy a 'leccie rattle gun and hope that will move the bugger so I can sort at home (not convinced anything short of mega-bucks pro kit will stand a chance) - not attractive; I don't really need the tool and it will probably just go on the shelf with a load of other largely unused kit after failing to do the job. The money would be better invested elsewhere (different daily snotter perhaps).
Drive it (even more gingerly) to mate's workshop as is, stopping regularly to make sure the belt is hanging in there - if it lets go there's a good chance of damage to timing belt behind it and/or other soft components nearby. Belt seems pretty unscathed so far but I doubt much warning will be given.
Drive it (less gingerly but still cautiously) after cutting belt - much less chance of catastrophic damage but no PAS and no charging (hence title) - no idea whether a charged battery will see me 30 miles/an hour up the road if I keep everything I can off.
Discuss....
Yeah I could have it recovered but where's the fun in that?
Doctor Volt said:
As Conian has already commented - You will cover 30 Miles without any problems unless you do the journey with heated rear screen, blower and headlights on. If you are still not sure that you should chance it you could take a spare charged battery with you
I think you'd get 30 miles even with all that on.The biggest drain is the starter motor.
Mate of mine had no alternator on his astra, drove for couple of days (without lights etc) between battery charges.
Conian Commented
"I think you'd get 30 miles even with all that on.
The biggest drain is the starter motor"
You are correct - The "think" part of your comment is how things so often fall over - The problem arises when there is a ? against the condition of the Battery, as we all know, even a Battery close to the end of its life will often start a vehicle and once the Alternator kicks in and is charging the vehicle will run ok.
Running a vehicle for any distance with no Alternator charge and a tired Battery is leaving things in the hands of the Gods
"I think you'd get 30 miles even with all that on.
The biggest drain is the starter motor"
You are correct - The "think" part of your comment is how things so often fall over - The problem arises when there is a ? against the condition of the Battery, as we all know, even a Battery close to the end of its life will often start a vehicle and once the Alternator kicks in and is charging the vehicle will run ok.
Running a vehicle for any distance with no Alternator charge and a tired Battery is leaving things in the hands of the Gods
Thanks for comments - plan is to set off with the belt intact and trust that if/when the charging light tells me it has given in, I can kill the engine and pull in before it takes anything else out. Will take a Stanley and then try another leg after cutting/removing the belt (recovery as the fall-back).
Reason for not just taking the belt off immediately is I reckon that's probably all that is holding the track part of the pulley in place... as long as loadings are kept light by not using big throttle,electric or steering inputs, I'm hoping the belt will stay in place and keep the pulley in-line where it's not going to clout anything. If I just chop the belt, I suspect the pulley will wander further inboard where it's not wanted (it can't escape outwards). Although the pulley parts are jangling away merrily when its running, the belt is not jumping around or bouncing so we'll see...
Reason for not just taking the belt off immediately is I reckon that's probably all that is holding the track part of the pulley in place... as long as loadings are kept light by not using big throttle,electric or steering inputs, I'm hoping the belt will stay in place and keep the pulley in-line where it's not going to clout anything. If I just chop the belt, I suspect the pulley will wander further inboard where it's not wanted (it can't escape outwards). Although the pulley parts are jangling away merrily when its running, the belt is not jumping around or bouncing so we'll see...
Being electronic it'll give you the finger somewhere around 10 volts. There are all sorts of things you can do to apply more power and keep it moving though.
The old mechanical diesels don't give a damn about electricity as long as they get cranked to start and don't get their fuel shut off when the power goes out.
The old mechanical diesels don't give a damn about electricity as long as they get cranked to start and don't get their fuel shut off when the power goes out.
packman10_4 said:
The ECU will need a constant 9.5 volts to work , if your going to make the trip charge the battery up and dont use heater lights radio ect ect ...
Depends what the threshold in the system is set to, this will depend not just on the ECU, but all the other components in the system.Primarily injectors and other solenoid/motor operated components.
Personally I would cut the belt off before driving it.
My reasoning being the belt has a degree of tension on the pulley therefore putting a certain amount of pressure onto what is already a damaged pulley.
Once you get up to a certain revs that pressure is increased giving even more chance of the pulley collapsing completely. If the belt snaps and wraps itself around the pulley the engine could lock up.
Or you have parts of a broken pulley trying to escape from an engine bay at say 2-3000 rpm - slice through the sump, big dent on underside of bonnet, slice a brake line...
Or chunks of metal flying out under car into car following you, or even pedestrian.
My reasoning being the belt has a degree of tension on the pulley therefore putting a certain amount of pressure onto what is already a damaged pulley.
Once you get up to a certain revs that pressure is increased giving even more chance of the pulley collapsing completely. If the belt snaps and wraps itself around the pulley the engine could lock up.
Or you have parts of a broken pulley trying to escape from an engine bay at say 2-3000 rpm - slice through the sump, big dent on underside of bonnet, slice a brake line...
Or chunks of metal flying out under car into car following you, or even pedestrian.
Ok, did it with the belt in place and it got me there still charging and belt still intact (remarkably unscathed in fact, at least visibly). For (short) spells it was even quiet - which was actually more worrying than the clattering. Very gentle inputs and low revs/speeds.
With the pulley off, there are witness marks on the rear of the inner (the belt drive part) that show it had moved around sufficiently to contact the engine cover (there was no damage to the cover however). The inner had completely sheared away from the front plate (the crank driven part). I was entirely satisfied there was no way the thing could get free of the engine (the front plate is very solidly made and the inner is retained by it); else would never have attempted it. I think I have been fortunate it has not gone back and damaged the motor (once sheared there is nothing to prevent this except the belt locating it). In those terms, it seems I made the right call as I think cutting the belt would have hastened disaster.
It's the first time I have broken a harmonic damper pulley - well worth looking at one to see what horrible things they are...
With the pulley off, there are witness marks on the rear of the inner (the belt drive part) that show it had moved around sufficiently to contact the engine cover (there was no damage to the cover however). The inner had completely sheared away from the front plate (the crank driven part). I was entirely satisfied there was no way the thing could get free of the engine (the front plate is very solidly made and the inner is retained by it); else would never have attempted it. I think I have been fortunate it has not gone back and damaged the motor (once sheared there is nothing to prevent this except the belt locating it). In those terms, it seems I made the right call as I think cutting the belt would have hastened disaster.
It's the first time I have broken a harmonic damper pulley - well worth looking at one to see what horrible things they are...
Pupp said:
Ok, did it with the belt in place and it got me there still charging and belt still intact (remarkably unscathed in fact, at least visibly). For (short) spells it was even quiet - which was actually more worrying than the clattering. Very gentle inputs and low revs/speeds.
With the pulley off, there are witness marks on the rear of the inner (the belt drive part) that show it had moved around sufficiently to contact the engine cover (there was no damage to the cover however). The inner had completely sheared away from the front plate (the crank driven part). I was entirely satisfied there was no way the thing could get free of the engine (the front plate is very solidly made and the inner is retained by it); else would never have attempted it. I think I have been fortunate it has not gone back and damaged the motor (once sheared there is nothing to prevent this except the belt locating it). In those terms, it seems I made the right call as I think cutting the belt would have hastened disaster.
It's the first time I have broken a harmonic damper pulley - well worth looking at one to see what horrible things they are...
I had one disinigrate as I joined a motorway. I don't understand why they are not a service item at the same interval as belts. It's made of rubber. It's going to fail. Irritating buggers.With the pulley off, there are witness marks on the rear of the inner (the belt drive part) that show it had moved around sufficiently to contact the engine cover (there was no damage to the cover however). The inner had completely sheared away from the front plate (the crank driven part). I was entirely satisfied there was no way the thing could get free of the engine (the front plate is very solidly made and the inner is retained by it); else would never have attempted it. I think I have been fortunate it has not gone back and damaged the motor (once sheared there is nothing to prevent this except the belt locating it). In those terms, it seems I made the right call as I think cutting the belt would have hastened disaster.
It's the first time I have broken a harmonic damper pulley - well worth looking at one to see what horrible things they are...
Pleased to hear you got car moved safely Pupp.
I used Mk3 Mondeo TDCi for years and they are notorious for bottom pulley troubles.
One car I replaced pulley 3 times, even genuine Ford items disn't last.
Worst I had was a Citroen Xantia HDi where the pulley started to separate, throwing the belt in the process.
Problem with those cars was the belt run the alternator, braking servo and suspension so when you lose the belt the car suddenly drops and you have almost no brakes!
I used Mk3 Mondeo TDCi for years and they are notorious for bottom pulley troubles.
One car I replaced pulley 3 times, even genuine Ford items disn't last.
Worst I had was a Citroen Xantia HDi where the pulley started to separate, throwing the belt in the process.
Problem with those cars was the belt run the alternator, braking servo and suspension so when you lose the belt the car suddenly drops and you have almost no brakes!
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