new head but tapping nose

[from_chevys2nissan]

i need help i got a 1989 240sx SOHC i just put a new head on it but have a tapping nose on the top of the motor, but the car drives good the nose just dont sond good.

and i have white smoke coming out the tail pipe only at about 3000rpm dose it comes out what might my problems be

[TheLogikal1]

is it all top dead center?

[from_chevys2nissan]

yes when i put on the head i put the motor on TDC before i remove the old head put a block in between the timing chain so it wont fall put the took the cam out the old put it in the new then put the new head on

[SHO411]

Sound like you did not do it right, We replaced the head of an old nissan truck couple of months ago, and the same noise was coming out, we thought the timing was right but it actually moved about 2mm off. Remove the chain and re-time the engine. It is not as loud cause it is a very small dist off, may be too small for you to recognize, but if you timed it more wrong more than that, the piston would hit the valve clean through your heads.

[from_chevys2nissan]

ok should i put the timeing mark on TDC when i time it or shoul i put the timing mark on 15 BTDC then i retime it

[from_chevys2nissan]

[quote=SHO411]Sound like you did not do it right, We replaced the head of an old nissan truck couple of months ago, and the same noise was coming out, we thought the timing was right but it actually moved about 2mm off. Remove the chain and re-time the engine. It is not as loud cause it is a very small dist off, may be too small for you to recognize, but if you timed it more wrong more than that, the piston would hit the valve clean through your heads.[/QUO


when i take the timing chain off do i put the timing mark on TDC or 15 BTDC

[SHO411]

There is a notch on the cam shaft sprocket, and there will be one on the plate behind the sprocket, line these two, put your #1 piston at TDC (always TDC), to clarify it's position, the notch on the crank pulley must align with the one on the block, as you mount the belt be sure none of them move even a degree off as you'll have to do it again. If you get confused, go to autozone and read the book for your model car, if you don't want to buy it. only costs $14, and tells you how to do tons of stuff. Rmember the notches are very small, they have to be exactly lined up. Once you are done, take a wrench and turn the engine no less than two times, you always have to do this before you ever turn on an engine, unless you are highly skilled, my boss worked on cars for the last 22yrs, he never did it, I, only 1 1/2yrs under my belt, I have to do this. like I said, sometimes shit slips and you can't tell cuz you don't know where the pistons are, so you turn on the engine and boom, you now owe the customer a new engine. that is why some ppl always retime the block even if they were just replacing a timing belt, it is safer, and for sure it is lined up.

[from_chevys2nissan]

Originally Posted by SHO411

There is a notch on the cam shaft sprocket, and there will be one on the plate behind the sprocket, line these two, put your #1 piston at TDC (always TDC), to clarify it's position, the notch on the crank pulley must align with the one on the block, as you mount the belt be sure none of them move even a degree off as you'll have to do it again. If you get confused, go to autozone and read the book for your model car, if you don't want to buy it. only costs $14, and tells you how to do tons of stuff. Rmember the notches are very small, they have to be exactly lined up. Once you are done, take a wrench and turn the engine no less than two times, you always have to do this before you ever turn on an engine, unless you are highly skilled, my boss worked on cars for the last 22yrs, he never did it, I, only 1 1/2yrs under my belt, I have to do this. like I said, sometimes shit slips and you can't tell cuz you don't know where the pistons are, so you turn on the engine and boom, you now owe the customer a new engine. that is why some ppl always retime the block even if they were just replacing a timing belt, it is safer, and for sure it is lined up.

ok thinks i will try that in the morning

do you think i messed my engine up all ready. cause i did not turn the motor befor i crunk it. well i hoope not these dam nissan parts cost a lot of money. i can get a complet engine gasket set for 35.00 for my chevy v8 but a head gasket set for my nissan coasts me 94.00

[SHO411]

That I can't say, try pulling out the plug and use a small flash light to see if there and big dents on the piston top. I really don't want to give you bad news, but from the explanation you gave me, everything points to that, I know cuz we did it in school to someones truck, there wasn't any damage cuz usually it just kicks the valve back up and makes it slip around the camshaft, check your lodes on your cam shaft to see if there are any scratch marks, and next time I would advise you to read the book and then attempt the work, I do it most of the time if it is my first time.

[from_chevys2nissan]

thinks for the help ill do that