MF147 engine locked up

[salicaspain]

Hi! I own a MF147, made under licence by Ebro in Spain, which I suspect is a re-badged MF135 - for the purpose of my query, the engine is the same 3.152.

I was losing power, and oil was leaking via the dipstick, so I suspected a problem with the piston rings. Having removed the head, I could find no problems with the pistons, but the timing was wildly out, with tappet gaps of 1/2" instead of 12 thou - one of the cylinders was not firing at all, which probably explains the loss of power. Having re-assembled the head, I wanted to adjust the timing - the engine would only turn anti-clockwise by hand (when viewed from the front) - the engine rotated a full turn, with all pistons operating, and then locked - I cannot now turn it in either direction. I have tried some gentle persuasion by attempting to tow in gear, with the same result. The rods from the tappets to the cam shaft are all free.

Can someone please advise as to why the engine has locked up, and how do I go about unlocking it? Thankyou.

 

[pmsmechanic]

Just guessing. Head gasket leaking. Cylinder full of water/antifreeze. Removing injectors will let you turn the engine over but if there is water in the cylinder then you'll need to remove the head and figure out why

 

[Kenneth S]

Just guessing. Head gasket leaking. Cylinder full of water/antifreeze. Removing injectors will let you turn the engine over but if there is water in the cylinder then you'll need to remove the head and figure out why

That is what I would do first ^^^^^^^^^^^^^^^^^^^^^^

 

[salicaspain]

No - I had the head off, and no problems evident - if there was water in the cylinder, it would come out of injector hole. This is a hard physical 'block'.

 

[jaotguy]

possibly .... the valves being loose by 1/2" means some were stuck open ( stopping it from turning in one direction ) you turned in the opposite direction till you encountered another and locked up the motor ( and other valves are now holding the piston captive ) or the cam shaft is bound up on some of the stuck valves )

remove the rocker cover ( and check the movement of all the valves , tap/carefully pry on the valves and see if any are stuck ....) remember, some will be sitting on top of pistons and won't move much ....

 

[pmsmechanic]

Well then there is something in the oil pan hitting the crankshaft. (Unlikely). Did you overtighten the head bolts and distort the block? Is a valve hitting the piston?

 

[Kenneth S]

I'd drop the oil pan, and have a look it's not too hard to do.

 

[salicaspain]

The valves were not 'loose' - there was a large gap between the tappet and the valve stem, and the valves were held shut by the springs. Why would there now be something in the oil pan when all I have done is taken the head off and put it back again? The engine was running beforehand.

 

[pmsmechanic]

Obviously the is something that is preventing the engine from turning. You didn't leave something laying on top of the piston when you put it back together?

 

[Kenneth S]

If you have the head back on it, and didn't leave anything laying on top of the piston, you can remove the rocker arm shafts, make sure all the valves are closed, and see if the engine will rotate over. When you turned the engine over until it locked up could you turn it back the opposite way, or is it stuck there where it locked-up?