So plain and simple the piston makes scrapping sound at every rotation WHEN THE SPARK PLUG IS IN, ONLY ON #4. I rebuilt the motor and haven't got it running yet(bad coil pack or wiring) but when the starter cranks it makes a scrapping sound, even with the SP halfway in. I know it sounds completely odd as the piston would hit the valves first but there fine. I've checked piston height and its same as #1, also the head is level(put on glass table, only one sheet of paper fit under and if it were that off to be hitting it would be more warped. The SP's sit higher up so it will smack the head before the SP. Timing belt was still aligned PERFECT when I took it off but again its only with the SP in which makes no sense.

Anyone know whats going on?

 

are you sure it's hitting the spark plug? are there marks on the electrode or a crushed electrode (tip of the spark plug)

sounds like rings scraping. the spark plug being in could cause the compression needed to push on the rings making them tight up against the wall...check and see if the cylinder needs to be honed...look for the cross hatch pattern, about 60 degrees is best with the larger angle on top and bottom...

 

Engine was honed at a shop. I'll check the hone job in the morning but I believe it was 60 degree. That cylinder had a chipped piston in it, but when I first pulled it apart the was no fragments of the old piston. So if this is the case, are the rings making noise cause the cylinder is uneven or scratched? Whats my best option here??



EDIT: Inspected it, wiped it dowm. Seem to have some tiny tiny fragments of metal I'd say from the hone job(did clean it out, guess not good enough). Also some black crude a top the piston. Anyway to clean this off without scrapping it as I don't want to damage the piston head? After I do this I will put the head on and try cranking it. Should I put a tiny bit of oil in there??

 

you should prime the oil system before you start it, otherwise the engine will take a couple of seconds before it gets pressure. The black stuff is carbon buildup i just used scotch brite to get it off.

as for the sound, pistions hitting things dont realy make a scrapping sounds. So i would tend to agree with sabin suggestion

 

Ya after all I've check seems he's right.

How would I prime it?

I'd hope that once I get her running the oil will get in there and make it ok, but I don't want to damage it if it takes some time.

Would putting some oil in work at all?

EDIT:I bolted the head on again and put the belt on. Same problem. The compression from the SP is obviously causing it, as I had it like 1 turn in and it was happening.

Is it possible the cylinder is uneven at the top?
Now I did do the pistons all at the same time, and put all black rings on at once and all silver after that to make sure it was right, but just incase would have the rings backwards cause this?(just incase all else fails and I have to pull the piston to look at it?)

 

the ring on upside down would cause it. there should be a dot on the ring telling u which side is up. also, you will need to check for scratches in the sides of the rings. when you do start it up, I would put about two - three cap fulls of oil or assembly lube in the cylinder too. starting your troubled cylinder at BDC, rotate the crank by hand for a few turns before putting in the spark plugs...Might I also suggest doing a compression check on all the cylinders before putting in the plugs...this will tell you a lot about what's going on inside the combustion chamber. one more thing before installing the plugs...turn your engine over with the starter for a few revolutions to evacuate the excess oil from the cylinders...helps prevent misfire and fowling out the plugs.

I just went through the same problem w/ my motor after getting it back from the machine shop...turned out they didn't hone the cylinders good enough. They only went w/ one 300 grit hone instead of starting out coarse and going to fine. It caused two of my cylinders to scrape the rings causing me to do them myself.

 

Ok I guess I'll pull the head again, pull the piston and inspect it(although the N was the mark on the rings, and it went up, of course I probably dropped it, picked it up and put it on wrong lol). I don't know how to hone a cylinder(any info would help,where to buy,price) but might be tough to move the car to get it honed. I was told this was a good rep shop that did it(20 bucks seemed cheap??) but that was the cylinder the chipped piston was in, maybe it just needed extra honing..I did show him the scratches though and he said it was fine.

ALSO, if i cover the crankshaft and everything under the cylinder can I hone it with everything still in there other then that #4 piston? I also have a magnet to put in the rag to catch the shrapnel.

Knowing m luck its probably not these things, but while its out of the engine, anything else I can do to ensure it fixes it?

 

Ok what do you know. The top ring was upside down. I'll keep you posted on it when she's bolted back on.

Also, if I'm not getting a spark whats the causes? I tried two coil packs and another SP wire(it was for DOHC but..). I haven't gotten a voltmeter to test the plug but anything else that could cause it? ground is good to the head.

 

do you get fuel pressure? usually they both get shut down w/ the auto shutdown relay...if you just missing spark, i would look at the cam and crank sensor. Yes it is ok to hone just that one cylinder, as long as you have everything covered like you said.
also, clean out the cylinder w/ a lint free cloth and some ascetone or rubbing alcohol, helps pick up all the fine particles.

 

Ok put everything back together and same thing....Cleaned and lubed the cylinder and rings.. I do have fuel pressure to the fuel rail, but as I said before I haven't gotten it started since there was no spark going on. Is it possible the timing belt isn't tight enough, the tensioner has the bolts all the way at the top..reason is I used a used one(had under 200 miles on it so theres no reason not to) and I obviously couldn't bolt and pull the pin so had to pop it on at the top. The marks from the old bolts show they sat 1/4 - 1/3 of an inch lower, meaning the tensioner was up higher and belt was tighter. Idk how tight the belt should be but I don't see enough slack to cause problems. Not even sure if it could skip a tooth just by cranking the starter.. could it? In this case, I'd think it would be hitting the valves. Does it make a scraping sound?(there were no marks on the piston, and valves seemed fine)

I heard they were 80 bucks, and it would suck to buy a new one then put it on still have scrap and not be able to use it after cause seems impossible to get the pin back in..

Also, could this noise possibly be from the main bearings perhaps they are damaged? Cylinder walls were also smooth as butter....


Figured I'd also point out, at the bottom of the cylinder seemed to be some corrosion or fresh rust and couldn't be seen from the top so I doubt the piston is scrapping it and carrying it up and then making the noise at TDC, but figured I'd mention just to be safe. I did oil the cylinders right after I got it honed to prevent rust so it probably happen somewhere down the road after putting it together and it had a dry spot.

AND UM, FEEL KINDA DUMB NOW THAT YOU MENTION CRANK SENSOR, BUT IT THIS LOCATED ON THE BACK OF THE ENGINE? CAUSE IF SO, MY 98 HARNESS DIDN'T FIT THE 95 SENSOR AND IT WASN'T CONNECTED,SAME WITH THE (crank)SENSOR NEAR THE OIL FILTER( http://s37.photobucket.com/albums/e6...tionSensor.jpg ) AND THE FRONT ENGINE SENSOR NEAR THE COOLANT WATER PUMP LINE. I'M GOING TO LOOK FOR THE 95 PLUGS TOMORROW BUT I THOUGHT THE CAM SENSOR MANAGED SPARK, as it connects to the head and the coil pack, fuel injectors, etc are connected to the head also. *smacks own head*

And spark only happens when the injectors spray right? Means the coil pack is fine then....