valve timing problem

[talonkev]

I put a new oil pan gasket on my car today and never manual turned over the motor or anything during the install. I started up the car and immediately heard a kinda knocking sound coming from the top of the motor. I didn't rev the motor or anything stupid like that, and immediately pulled the valve cover and began to check things out. I discovered that both my cams are in time with each other, but at almost exactly TDC the I can feel the pistons tap the valves on the intake side when I turn the motor over with a wrench. My question is how can the motor jump time in a manner that would allow the intake valves to open before the piston reaches TDC, would the rotation of the crank make it skip in the opposite direction? Do you guys think any damage is done? Any help from you Wiseman would be greatly appreciated.

 

[CorrupTTalon]

I put a new oil pan gasket on my car today and never manual turned over the motor or anything during the install. I started up the car and immediately heard a kinda knocking sound coming from the top of the motor. I didn't rev the motor or anything stupid like that, and immediately pulled the valve cover and began to check things out. I discovered that both my cams are in time with each other, but at almost exactly TDC the I can feel the pistons tap the valves on the intake side when I turn the motor over with a wrench. My question is how can the motor jump time in a manner that would allow the intake valves to open before the piston reaches TDC, would the rotation of the crank make it skip in the opposite direction? Do you guys think any damage is done? Any help from you Wiseman would be greatly appreciated.

i think youre leaving out some important info here man.

you went from an oil pan gasket to the timing.. two totally unrelated parts of your engine.. you dont need to mess with the timing in order to replace your oil pan gasket..

so tell us what you did with the timing.

yea the cams lined up, big deal.. you still need to make sure three other points line up. only one(crank) if you have the balance shafts removed.

youll need to rotate it up to 6times in order to get everything to line up due to the oil pump gear ratio(CLOCKWISE). if your balance shafts are out of phase for whatever reason then youll get knock.

just give more info on what you did

 

[Defiant]

Jumped timing when starting, the usual place it happens. You did put the short bolts back under the crank sprocket, didn't you?

 

[ddavisaf]

Jumped timing when starting, the usual place it happens. You did put the short bolts back under the crank sprocket, didn't you?

Beat me to it

 

[talonkev]

"so tell us what you did with the timing."
I never touched any of the timing components at all, the timing covers were on and I never turned the motor over using the crank nut intill after it already jumped time. And I always turn it clockwise.

"You did put the short bolts back under the crank sprocket, didn't you?"
Yes, for the three front oil pan bolts I used the short bolts. I actually used a long one once and it cut a groove in the belt, but didn't cause it to jump time. The valve timing has been reset since then also so that has nothing to do with this problem.

Thanks for the input guys, but im still wondering how the intake valves can open before the piston reaches TDC? If the belt slipped on the crank pulley wouldn't it retard the intakes not advance them? Also does any one have any input on the probibility of internal damage?

 

[gurrmanator]

"so tell us what you did with the timing."
I never touched any of the timing components at all, the timing covers were on and I never turned the motor over using the crank nut intill after it already jumped time. And I always turn it clockwise.

"You did put the short bolts back under the crank sprocket, didn't you?"
Yes, for the three front oil pan bolts I used the short bolts. I actually used a long one once and it cut a groove in the belt, but didn't cause it to jump time. The valve timing has been reset since then also so that has nothing to do with this problem.

Thanks for the input guys, but im still wondering how the intake valves can open before the piston reaches TDC? If the belt slipped on the crank pulley wouldn't it retard the intakes not advance them? Also does any one have any input on the probibility of internal damage?

are you sure its your intake valve???that intake valve should NEVER be open when the piston is coming to the top. you must be talking about your exhaust valve.you better start from scratch with your timing and make sure everything is to spec.

 

[talonkev]

I built this motor, I know enough about it to be able to distinguish the exhaust valves from the intake valves. Yes I know im going to go pull the timing cover off now and reset every thing. I realize that the intake valves should never open before the piston reaches TDC, that is why I am so confused?

 

[DSM90AWD]

If the belt slipped on the crank pulley wouldn't it retard the intakes not advance them? Also does any one have any input on the probibility of internal damage?

I jumped a couple of teeth once when I cranked the CS pulley the wrong way
Made a bit of metal-on-metal clatter when I started it up (immediately shut down car), but after resetting the belt, the noise subsided and compression was good, so guess I dodged a bullet.

 

[CorrupTTalon]

Guys i have cranked the crank counterclockwise before, BUT not in full rotations.. only to go back maybe 180, not even to line the marks back up if i turned too far counter clockwise.


can you tell me what this does and why its bad? if everything is timed how could it hurt something when everything will be just moving in a backwards motion but all is still in time..?

talonkev, I hope you dont mind me asking this question in your post!

 

[talonkev]

The tensioner is on the back side of the belt that doesn't get pulled on then the motor is turning clockwise. When you turn it the opposite way and can slack the front side of the belt and it can jump teeth, because the tensioner is tensioning the side of the that already has pressure on it. Any amount of counter-clockwise turning can cause the belt to skip. Sorry bout the confusing explanation, I don't know how else to say it.

On another note, I reset the timing and started her up. She runs perfect and the compression is 163ish across the board, so I guess I got lucky on this one. thanks for all the input.

 

[CorrupTTalon]

good to hear bro, i dont really understand what you said but its 4:30am.. i re read it tomorrow haha...