Think I have seized my engine

[rafiki_]

Do not attempt to turn the engine in gear from the propeller coupling, this will try and turn the engine through the gearbox and this is a bad idea.

Take the starter off, take the gearbox off, check the oil, pull the injectors. Try to turn the engine using the crankshaft nut - you may need to hire a 1" drive socket set with a large enough socket to do this. If it still won't turn over by hand in this state it is stuffed and is truly seized. In this case you may be able to hire or borrow a borescope to look inside the cylinders through the injector holes and see if any are scored or scuffed up, which will give you a clue what is going on.

If the engine still does not turn over on a good starter but can be turned by hand, it is possible that the main bearings are so worn that the crankshaft and/or pistons, even the flywheel are jamming when the starter ring gear engages, but this is unlikely as an engine that far gone would have practically no oil pressure and be noisy as f@ck when running. My money is on the gearbox but if you do the tests I have proposed you will find out what the problem is and do no further damage in the process.

I'm interested in your thought process, but surely smoke from the rocker gasket and dipstick tube are more indicative of an engine issue than transmission?

 

[nashynetfit]

Do not attempt to turn the engine in gear from the propeller coupling, this will try and turn the engine through the gearbox and this is a bad idea.

Take the starter off, take the gearbox off, check the oil, pull the injectors. Try to turn the engine using the crankshaft nut - you may need to hire a 1" drive socket set with a large enough socket to do this. If it still won't turn over by hand in this state it is stuffed and is truly seized. In this case you may be able to hire or borrow a borescope to look inside the cylinders through the injector holes and see if any are scored or scuffed up, which will give you a clue what is going on.

Assuming that it is capable of being turned over by hand (which I bet it is, your description does not sound like an engine seizing through lack of oil but it is possible until you prove otherwise) then carry on to a starter test. Charge the batteries and test the starter off the engine. If it spins then refit the starter, if not then fix it or have it fixed. Once the starter is known to work and refitted, try to turn the engine over on the starter. If it turns over, then refit the injectors, bleed the fuel system and see if it starts. If it does not turn over on the starter with the injectors out, then again try and look inside with a borescope. If the engine rotates with the injectors out then put them back in, bleed them and see if it starts. You will not do harm by running the engine without the gearbox attached. Assuming it starts then your problem is in the gearbox, which is where you started... At least a gearbox costs less than an engine.

If the engine still does not turn over on a good starter but can be turned by hand, it is possible that the main bearings are so worn that the crankshaft and/or pistons, even the flywheel are jamming when the starter ring gear engages, but this is unlikely as an engine that far gone would have practically no oil pressure and be noisy as f@ck when running. My money is on the gearbox but if you do the tests I have proposed you will find out what the problem is and do no further damage in the process.

Many thanks Janglesea. Will go through the steps you've described, the thought of trying to strip down the engine to repair would be too much, but seen the starter motor test via youtube, so shall start there then after keeping my fingers crossed, see what else is going to happen.

Any reason why the engine would stop when changing from forward to reverse, revs went high as wanted to test the engine.

Thanks again for your time.

 

[volvopaul]

The logical next step for me would be to invest in a borescope, they're not expensive on ebay

Bmc 2.2 is indirect injection , I'm afraid you cannot see the piston top or bore as the injector protrudes into the combustion chamber only not the cylinder bore.

We're not talking a fortunenforma new head gasket here so get the head off.

You can also remove the starter motor, far easier than a gearbox to turn the engine over by hand.

What model of gearbox do you have ?

 

[SC500]

Interesting to follow this one. IMO smoke from rockers and dip stick is a sure sign of Crank case pressurisation generally caused by failed cylinder liners (if fitted), head gasket or head. Somehow combustion gas is getting past the piston rings. As VP says, get the head off and it should become obvious. Surprised there was not coolant leaks externally if there was a failure, but worth checking your oil to see if there any signs of water emulsion internally in the oil, (creamy looking stuff). If leaking water was around it could possibly fill bores and cause hydrlock (engine siezure). Could be something else, but cant see how this would cause crankcase pressurisation. Best of luck.

 

[janglesea]

Check one thing at a time. The engine appears now to be seized but this is not confirmed. Removing the gearbox will ensure that this is not the cause of the lockup; the gearbox is the most recent work done on the engine. This can be tested without taking the head off by using a large socket and trying to turn the engine in both directions.

If the engine cannot be turned by hand then I would still try a borescope as it may be able to reach the cylinders through the combustion chamber ports. The last time I checked you could get a USB "snake" camera on Ebay for less than £70 with a head diameter of 7mm. That is small enough to pass many injector holes and maybe the combustion port as well. If the borescope shows water in the cylinders or scoring/pitting to the liners then this would indicate that pulling the head would be worth doing.

The crankcase smoke is suspicious but not definitive. I have seen lots of diesels working away while chuffing smoke from the crankcase breather and the dipstick tube. It is never a good sign but it does not always mean that the engine is about to die. I have run several vehicle and plant engines to destruction after they have been abused/neglected by staff and previous owners. That has always been a conscious decision based on careful diagnosis and fault finding. One always has to weigh the cost of repairs against the cost of replacement. Sometimes they run for a surprisingly long time with gross and obvious faults.

The BMC 2.2 is a tough little beast and from what has been reported so far this one may well have some life left in it.

 

[Cliveshep]

It is of course entirely possible that the gearbox is the problem and that it is seizing up. That could perhaps overload the engine which would cause some smoking? Also would reflect on a starter motor's inability to turn the engine over?