Engine Help

[jeremy manlief]

hello. i have a 95 mtx. i am doing some big maintance to the engine, like clutch change, rod bearings, 60k tune up, etc. the first thing i did when i got the oil pan off was change the oil pump and front seal. that went smooth. next, i change the rear carrier gasket and rear main seal and cleaned the dirt and grease from the clutch and rear seal being bad off of the back of the block. that went smooth. next i changed the rod bearings. that went smooth also. i assembled the bottom end(stud girdle, and windage tray and oil pump pick up) and put the oil pan back on. when i tried to turn the motor by hand, it would only turn so far and stop dead, then i would turn it the other way and it will only go so far and stop dead. i noticed this when i was changing the rod bearings and i thought it was a piston hitting a valve, but i have read that these engines are non-interference motors and the engine was turning just fine by hand when i was removing the flywheel. next, i thought it might be the oil pump so i took back off the oil pan and removed the oil pump and it still does the same. i then took back off the rear carrier and it still does the same. i even loosened the rod caps and still the same. i inspected the rod bearings and they are just fine. now the crankshaft is really stiff to turn and it will free up in spots and still stop dead after you turn it so far. it will not turn a full revolution. i didnt change or mess with the main bearings or caps. could this be my problem? i coated the rod bearings with plenty of oil and i dont think this is the problem. i am using torque specs from the dealer manual and a good torque wrench to torque everything down. any help or theories on this problem will help me in a big way. thanks

 

[masho95]

How hard are you trying to turn over the engine by hand? If you've never done it before the problems, and don't know hard it's supposed to turn, there is a spot where it gets tough to turn. And out of curiosity why did you change the oil pump??? If the oil pan is still off have someone try turning the engine while you look at the crankshaft and see if anything is binding up.

 

[jeremy manlief]

before i took the oil pan off, the engine was really easy to turn by hand with no catches or stops. i have the top of the engine tore apart to do the valve adj. and timing belt, plus other things, but i havent replaced anything yet at the top end. just getting it ready. i started at tearing down the top of the engine and then i worked my way down to get the tranny out to do the clutch and rod bearings and the engine turned by hand just fine when i got that far. when i was getting the flywheel off, the engine turned by hand with no problems, even with the timing belt off. i am replacing the oil pump since my car has 140,000 on it and the rods knocked on start up only and since i am down that far, i might as well replace the oil pump for extra insurance. i am able to turn the engine by hand with a ratchet from underneath the car by myself and i dont see anything wrong for as far as i can turn it before it stops.

 

[NotSoSlowSHO]

Are you sure it isnt just compression?

Is the timing belt on?

Have you tried pulling the plugs, then spinning the engine?

 

[masho95]

before i took the oil pan off, the engine was really easy to turn by hand with no catches or stops. i have the top of the engine tore apart to do the valve adj. and timing belt, plus other things, but i havent replaced anything yet at the top end. just getting it ready. i started at tearing down the top of the engine and then i worked my way down to get the tranny out to do the clutch and rod bearings and the engine turned by hand just fine when i got that far. when i was getting the flywheel off, the engine turned by hand with no problems, even with the timing belt off. i am replacing the oil pump since my car has 140,000 on it and the rods knocked on start up only and since i am down that far, i might as well replace the oil pump for extra insurance. i am able to turn the engine by hand with a ratchet from underneath the car by myself and i dont see anything wrong for as far as i can turn it before it stops.

Why are you trying to turn the engine over with the timing belt off? :ruhroh:
Also you should finish with one section of the car at a time. Do you have the valve covers off? Leaving them off while doing other work is just inviting dust and other debris to get in there. Is the timing belt still off?

 

[jeremy manlief]

all plugs are out. timing belt is back on. i had to take off the timing belt to change the oil pump. i have had the timing belt off and on a few times but alway put it back on, in time. i know about dirt and stuff, but i have always kept every thing well covered when i am not working on it. i never left anything exposed, but if i had to, i kept that area well covered with lots of towels. this didnt happen till i took off the oil pan. when i was changing the rod bearings, i did one at a time and as i was turning the motor by hand to do the next one, thats when i noticed that it would lock up in one spot, and i had to turn it the other direction to do the ones i couldnt get to, and it also locked up when you went so far that direction, almost a full revolution. now, its really stiff to turn in one area, but frees up before it locks up, in both directions. all was fine before i did the oil pump, rear seal and carrier gasket and rod bearings.

 

[NotSoSlowSHO]

sounds like something is overtorqued. Or a bearing isnt seated correctly.

Better start checking your "work". Something is not up to *****.

 

[jeremy manlief]

i will recheck the rod bearings, but i dont think its the problem. when i changed the first bearing i was doing, i turn the engine by hand to start at the front one and work my way back and thats when i noticed that it would lock up when i turn the engine so far. none of the other bearings were changed at this time except for the one i did. i rechecked that first one i did and it is just fine. almost feels like a main bearing problem, but i didnt touch any of that or loosen the caps and i still havent touched them.

 

[jeremy manlief]

i have come to a conclusion on my problem. i think the #3 piston hit a valve. everything is nice and free to turn by hand but it still locks up when you turn it so far. i was under the car turning the motor by hand and i can see the #3 piston all the way up when the motor locks up, and i can turn it the other direction and you can see the #3 piston travel down and back up and thats when it locks up. so i am going to finish the clutch job and get everything back together under the car, so i can get my engine support off the car, and unbolt the rear valve cover, since i havent removed it previously, and check the valves for that cylinder. if thats it, i guess i will be removing the rear head. is there anything i should be on the look out for when removing it and should i do the front head also, atleast the gasket. thanks.