Topher2253

Doing a timing belt change on 00 Honda civic ex. Ran into a few problems. So I thought the crank pulley bolt was going to be the hardest part and that actually came off quite easy and then I think I found out why. First mistake was I did not set the engine to TDC on compression BEFORE I busted the crank pulley bolt. When I realized this I thought I would just tighten the bolt back in and do it and so I did. I set it right before TDC so that when I loosen the bolt again I wouldn't go past (I was using the crank pulley bolt removal tool). Problem is I took the belt off before I did that so.. will it mess up the timing if I turn it a little more to get TDC with the belt off? the reason I think my bolt wasn't tightened all the way is because when I took the harmonic balancer off not only was there no woodruff key, the slot on the crankshaft for the key was chipped off on the right side and the teeth for the balancer were worn down. The previous owner fixed this by using red lock tying the pulley to the timing belt gear behind it. So the other mistake is before I moved around the timing belt gear I didn't notice where it was before I moved it. There is play in the gear so I do not know if I should time the engine with more to the right or left. I am going to get a new key, balancer, and timing belt gear all used and fill in the chip with jb weld and also lock tie it again because I cannot buy a new crank. I just want to get the engine timed right and forget about this disaster I bought. can anyone help me? anything input appreciated, thanks in advance.

ezone

Oh god.

Break the crank pulley bolt loose, then put the crank in time, then remove the pulley. THEN remove the timing belt.
Too late now though.

If there is no keyway in the bottom timing gear, then you really can't turn the crank all the way thru now.

You CAN turn the crank 1/4 turn and leave it there, this puts all 4 pistons at halfway in their stroke so you can spin the cam if needed (remove sparkplugs and verify all 4 piston positions with a long screwdriver if you doubt me). But you MUST know where each piston is at all times, and you MUST know what valves are open and closed at all times.

If you start with the crank on #1 TDC (#4 piston is also at the top of its stroke) if rotate the crankshaft 1/2 turn you will bend any valves that are open when #2 and #3 reach the top of their travel.
There are always valves that are open no matter what.

The timing gear keyway is supposed to be lined up exactly with the original key slot in the crank, never off to one side. If there is at least one side of the original key slot intact in the crank, you can pretty much get it close to right in time. If both sides of the slot are damaged, you may not get it in time. It would probably run, but be low on power depending on how far off it is.
(I used to see this happen a lot on old Mazda 323s.)


If the crank bolt won't tighten enough, all your work will probably be ruined again soon. Inspect threads and all that.


How much are you gonna spend on that?
Price the whole engine just in case. Probably can be had for $500 or less.
car-part.com

Topher2253

The thing is I DID time the engine to ALMOST tdc BEFORE I took off the belt or the pulley. I did this because I did not want to overshoot it when loosening the bolt. How would you turn the engine to time it AFTER you break the bolt loose?.. By hand? the engine is not completely in time YET, but will putting the old belt back on and timing it all the way work? or should I just turn the engine the rest of the way with the belt off and it wont make a difference? I am having a hard time understand why it would be different to time it with the belt on or off. It is currently on the compression stroke and about a centimeter from tdc. the keyway is only chipped on the front right corner of the crank, the section that holds the harmonic balancer woodruff key so I am not too worried about that after i fill in the chip and new key. I am guessing the built in key on the timing belt gear is damaged because the section that seats in on crankshaft looks perfect. Again the cam nor the crank have moved since I pulled the belt when it was timed to almost tdc on compression.

ezone

Yes.

You'll bend the open valves if you roll the crank through a complete revolution.


When the cam is set to #1 TDC, that's the ONLY one with valves guaranteed to be closed.
If you spin the crank without the timing belt on, the rising pistons can contact any open valves when the pistons come up. (valves are still open on cylinders 2 and 3)

If you don't know what is happening inside each cylinder as the cam and crank spin at different speeds, then you need to keep the crank and cam synchronized.

Oh ok, this is the important key I thought was you meant was missing! (Remember, I see TONS of different engines. They are not all constructed the same.)

I'd just move each one to where it needs to be by hand or with a wrench.

But do not turn either one through a whole revolution.
Simply move as little as possible to reach the timing marks.

Yes you can turn them backwards if you need to.

ezone

You can see some of the valves open in the middle two cylinders here, this head has the cam set at #1 TDC position.

Topher2253

Ok that makes sense thanks! yeah I would be afraid to do a full revolution, but now I know that should not be done no matter what. When I get the belt on there timed and tensioned I plan to do a full revolution or two to listen for metal to metal and check the marks. Hopefully I don't hear anything and its in time because then I really wouldn't know what to do.

ezone

Your car is a 2000, the service guide says to spin the crankshaft 6 full revolutions, then inspect the timing marks and retension the belt.