Help! Engine's stopped dead - totally!

[71Westy]

Back from 600 mile round trip to Dubs at the Castle, bus ran sweet on dual carriageway, but idling was very iffy.

Just checked the carb - cleaned it with carb cleaner - in advance of the tuner coming tomorrow. Checked No 4 plug and perfect colour. Went to try the engine, ran rough for couple of seconds. Tried again, and I'm not sure whether I was still cranking or it was running, but it stopped stone dead, with a squeak (I assume from the still spinning dynamo). The crank is totally locked. Then noticed I hadn't put on the No 4 spark lead.

Out of desperation, tried rocking back and forward in gear, and tapping the starter motor with a mallet, just in case it's a jammed starter. But nowt. Crank is locked solid. Turning the ignition just gives a click.

What have I done????

Nick

 

[kev mc]

poss spun a dowel. if the engine is locked solid then that sounds like a dowel has spun in one of the bearings, ususally the front one (flywheel end).
hope its not that and turns out to be something simple.

 

[Trikky2]

I would suggest removing the starter motor (in case you have seized it by keeping it engaged after the engine had started).

If after removing the starter motor you can turn the engine then it will confirm you need to repair or replace the starter motor.

 

[71Westy]

Yep, did that at 8:30 this morning. Came out easily, and engine still seized solid. No movement at all. Nothing visibly wrong on outide. Less than 2 year old engine, only 5000 miles - bugger.....

 

[Trikky2]

Bugger indeed

Next take off the fanbelt to see if maybe its the fan/dynamo that is seized. long shot I know but worth checking before going to the trouble of taking the engine out.

If the fan spins freely then check the engine pulley is not fouling/seized on the case. (came across this recently)

After eliminating these two then its engine out time I think

 

[Trikky2]

ps. I dont think you have "done" anything. Cranking over or running at low rpm, even with one plug disconnected, will not cause an engine to seize.

On a very new build having insufficient end float could cause a problem but you say its done a fair few miles so it cant be that. This only leaves the possibility of a seized bearing due to lack of lubrication (spun dowel as mentioned) or something jamming the cam gear for instance.

Unless of course something dropped into the inlet manifold when you did the carb ..... hmm

 

[71Westy]

It's not the dynamo and fan - that rotates.

The crankshaft pully is rock solid - absolutely no slack whatsoever. It hasn't moved to hit the case.

I did wonder if I had dropped something in, but I can't think what - I was very meticulous. I can't actually think what might have gone in.... I did pop off the air cleaner and check the little spray bar from the accelerator pump - that is a push fit. But it's all present and correct.

And anyway, if it had found it's way to a valve, would is really cause such a solid seizure??? I suppose if it's wedged a piston.....

All this, just when it was beginning to run right. Anyway, plan B for the holiday - dug out the tent, and now trying to cram into the car :-(

 

[the_troupster]

Might be worth removing the rockers before having to remove the engine? Could be something in the valve train.

Long shot though...

Jim

 

[Trikky2]

Anyway, plan B for the holiday - dug out the tent, and now trying to cram into the car :-(

I hope you still have a good holiday (even if it is in a tent) and that the weather is kind to you. (its really bad here at the mo and wont really improve till next week).

Do let me know what you find when you get round to dismantling after your break, I would be interested to hear.

 

[nora]

A few years ago a guy i work with dropped (by mistake) a small 8mm nut into the inlet of a CV12 engine from a Challenger tank. That started and ran then stopped suddenly, the small nut had finally made its way down into the cylinder and had caused the engine to sieze.

 

[71Westy]

So that could be it. Well apart from feeling a numpty, at least that won't be a strip of the crankcase...

Thanks for the advice and good wishes.
Nick

 

[71Westy]

Unless its bent the con-rod of course....

 

[nora]

Try to rotate the engine in the opposite direction, if it turns and then locks up again then there is something stopping the piston.
My mate caused £250,000 of damage with his mistake. Whoops.

 

[71Westy]

Doesn't turn either way, even with a spanner :-(

At least it wont be £250,000 of damage this time (unless I burn the house down trying to fix it - and the way things are going at the moment, the chances of that are quite high!).

 

[Gman86]

This happened to me shortly after fitting my new engine hadn't even driven it yet and shortly after turning it on it stopped so fast and compleatly that the dyno belt squealed round even tho the bottom pulley had stopped. I was so gutted and I franticly tried every thing you have and as I had just given up and decided it was a right off I decided to try turning the ignition key 1 last time and it suddenly came to life, was so relieved, I could not tell you what I did to relieve the problem. I think I was just lucky. However I would finish by saying that about 3000 miles later there was a massive failure of a big end righting off the whole block. A post-mortem did not find out why it happened so I can't say if the 2 are linked. I hope you get it running again with out to much problem.

 

[71Westy]

Same symptom - I got the squeal too. But no luck with the trying everythng and it going again :-(

 

[froggy]

Sorry to be the bearer of bad news but sounds like its an engine out and strip down job.
You might be lucky in that once you drop the heads off and remove the B&P's that the engine rotates, could just be as simple (?) as a seized piston if not and it does turn out to be a spun bearing / dowel then at the very least it a line bore but more than likey its a new crankcase / new engine.
Dont know what your mechanical skills are like but with a haynes (or bentley) manual its do-able on your drive with a basic set of tools and a torque wrench.

 

[71Westy]

Yes - I've mentally prepared myself for the new engine scenario... My skills are up to whipping the heads off - and I guess the barrels and pistons. Once it gets to opening up the crankcase, then I think that's where I stop and consider my options. With it being a recon engine, I don't know what's been done to it already, either.....

At the very least, I can treat this as education

Cheers,
Nick

 

[71Westy]

So after a holiday in a tent instead of the van, got the engine out to investigate.

So the long shot of something jammed in the flywheel was ruled out. Off with the heads - nothing untoward - no evidence of a foreign body jammed in the cylinders. Off with the barrels - all came out fine - and the pistons look ok (apart from one has some slight scoring on the skirt, which is odd) - all free.

Tried to turn it counterclockwsie with the crank nut, but with a mallet on the spanner, the crank didn't budge - but at least the nut's come undone!

Levering the flywheel (against the engine stand) does turn the engine, but it's incredibly stiff.

So what now? Its a rebuilt engine from a well known company, and has less than 5000 miles under its belt. I'm gonna call them for advice. And see what they've done with bottom end in terms of crank regrinding etc. I've bought the engine rebuild book recommended on here. So I might split the case and have a look - but this is very new territory for me.

Nick

 

[Trikky2]

Sorry to hear its turned out to be the bottom end somewhere.

Your right - the only thing you can do now is open up the case. I know it seems scary if you have never done it before but if you have stripped down this far it really isnt that much further to go.

In terms of complexity and time its in fact a lot less work than you have already done to get this far. Just use the workshop manual and be methodical and you will wonder what you were worried about when your done.

If the engine already covered 5000 miles I cannot see how it could be anything to do with tight endfloat and would suspect lack of lubrication.

Considering the conditions you describe when it happened you may find you dont need any re grinding eg. the surface will clean up and just need new shells - fingers crossed.