Looks like I messed up my timing marks? help!

[jesterdog]

I thought I did everything right. I found TDC. Then I rotated the engine until both timing marks lined up on both cam pulleys. I then proceeded to removed the belt etc. I removed my cylinder head and both pistons were not down in the block. My valves are partially open. So I started looking back at posts and pics. My crankshaft timing mark should be straight up, but it is not. It is about 1/4 turn clockwise. The cams are straight up. Was I supposed to keep turning the engine untill all of the marks lined up?

So what do I do now? I am taking the head to a machine shop to check flatness. I'm afraid that something is gonna shift. I can't think of how to reference everything now.

I mean, I guess the belt will go back on the same way it came off.

any wisdom out there?

[jbwood5]

Why did you set #1 at TDC? That is very bad and you may have bent a valve if you rotated the right (passenger side) cam sprocket with the belt off.

The proper way to do this, assuming you are replacing a non-broken belt, is line all the marks up as shown in the timing belt diagram. That will put the crank mark pretty much in the vertical position and all 4 cylinders half way down their respective cylinder. At that position, you can't bend a valve.

If you think you may have damaged a valve, ask the machine shop to pressure test your head. That will tell right away if you have a valve problem. Have them check for flatness and if no milling is required, get them to re-surface the head.

If you were using instructions from a Haynes manual, be aware that there are mistakes in that manual, especially the part that says set#1 to TDC. That is some carryover statement from other older engines. Shame on Haynes for not recalling all their manuals and correcting that.

[jesterdog]

Yes, Haynes manual. I did TDC and I thought I just needed to go from there to where the cams lined up....

[jesterdog]

Passenger side cam has not moved. Driver side is removed, and the exhaust/intake valves are open. I think that the rear piston is on exhaust stroke, so even though the piston is almost all the way up, it didn't touch the valves. We will see...

[jbwood5]

If the crank mark is at 3/4 (i.e. 9 O'Clock), gently rotate it clockwise until the crank mark is vertical. Stop if you feel any resistance.

Did you take the head off with the camshaft sprocket attached and untouched? (i.e not rotated) If so, you may be OK. If you rotated either sprocket, you may have bent a valve on the cylinder head.

[jesterdog]

Driver side cam moved when trying to remove sproket. I think when it moved it was closing the valves. Because it jumped to relieve tension. As I moved it back to the timing mark I believe it was compressing the valve springs. If it moved either direction it was coming off the springs/closing the valves. Looks like with the belt in place, it was intake stroke on one cylinder and exhaust on the other. Hopefully I can re-install, make sure the mark stays lined up and put the belt on.

[wallyblackburn]

You're OK. It's not critical to keep everything from moving until you're done - you just need to have it lined up when you put it together. As long as you stopped when you felt it hitting, you probably didn't bend anything.

There is a mark on the crank sprocket that, when it is straight up and aligned with the mark on the oil pump, puts all the pistons halfway down the bore. You should be able to find a pic here or somewhere pretty easily. With an SOHC (which is what it sounds like you have), you cannot damage anything by turning the cams in that state.

Your new timing belt should have marks that match the three marks on the sprockets. As long as those match up, you're good.

Good luck,
Wally

[jesterdog]

Ok, so what y'all are saying is: in my current state, (which is timing belt is removed) I can rotate the crankshaft counter clockwise until it's mark is straight up?
When I re-install the driver side head, I just need to make sure that all three marks are lined up: passenger side cam mark aligned with head seam, crank mark 12 oclock and driver side cam mark aligned with notch in inner timing cover. yes? Then I can put the belt on?

It seems like if I move the crankshaft with the belt off, and it moves independently of the camshafts, then I will put the engine out of time.

[RobLog]

First, what year and engine are you talking about? This would be enormously important.

Second, forget TDC. The factory service manual never even mentions it. Just get all the marks lined up.

Third, make sure you are using the correct marks on the crank sprocket. See graphic.



RL

[wallyblackburn]

Originally Posted by jesterdog

Ok, so what y'all are saying is: in my current state, (which is timing belt is removed) I can rotate the crankshaft counter clockwise until it's mark is straight up?
When I re-install the driver side head, I just need to make sure that all three marks are lined up: passenger side cam mark aligned with head seam, crank mark 12 oclock and driver side cam mark aligned with notch in inner timing cover. yes? Then I can put the belt on?

It seems like if I move the crankshaft with the belt off, and it moves independently of the camshafts, then I will put the engine out of time.

Yes, but by lining the marks on the belt up with the marks on all 3 sprockets when you put the belt on, you will cause the engine to be correctly timed.

Again, with the crank sprocket mark lined up at 12:00 with the mark on the oil pump (see pics to determine which marks I'm talking about), you cannot hit the pistons with the valves. So, it doesn't matter where the cams are when the heads are installed. At that point, you need to be worrying about properly torquing the head bolts - not where the cam is.

Assuming it is a SOHC motor (one camshaft per head). you can spin the cams every which way as long as the pistons are down in their cylinders. You just have to have them lined up correctly when you put the belt on and release the tensioner.

Good luck,
Wally