If the timing belt is already broken!!
#1
04-02-2008, 10:35 AM
If the timing belt is already broken!!
If the timing belt is already broken, will I be able to position the crank and the other positioning marks by hand, back to center with out damage to the valves or pistons?
[hr]The only stupid question is one you didn't ask!
[hr]The only stupid question is one you didn't ask!
#2
04-02-2008, 11:40 AM
RE: If the timing belt is already broken!!
Thisa '94 like your other thread? THAT'S IMPORTANT!
Keep in mind that the valves MAY have already been damaged while the engine coasted to a stop afterthe beltbroke.
Here's what you should do:
1) Remove all spark plugs so it's easier to turn the crank. Remove remnants of the timing belt, or cut it so the camshaft DOES NOT TURN.
2) Find the position of the TDC mark (single notch on the crank pulley). Move it DIRECTLY to a position 90 degrees away from the pointer. Either side, doesn't matter which, doesn't matter if you spin it backwards.
DO NOT MOVE IT THROUGH THE POINTER POSITION.
DO NOT MOVE IT THROUGH THE POSITION 180 OPPOSITE THE POINTER.
Now all 4 pistons are at mid-stroke and you can spin the camshaft any whichway you want.
3) I would turn the camshaft around & look for any large valve clearances. A bent valve will have excessive clearance to the rocker & cam lobe because it can't close as far as it used to. This may beobvious without even using a feeler gauge.
4) If you're lucky & none are bent you can continue...
Position the camshaft at it's timing marks.
5) Turn the crankshaft DIRECTY to it's mark, even if that means turning it backwards. It's OK for piston #1 & #4 to come to the top because those valves are closed. It's NOT OK for #2 & #3 to come to the top.
Keep in mind that the valves MAY have already been damaged while the engine coasted to a stop afterthe beltbroke.
Here's what you should do:
1) Remove all spark plugs so it's easier to turn the crank. Remove remnants of the timing belt, or cut it so the camshaft DOES NOT TURN.
2) Find the position of the TDC mark (single notch on the crank pulley). Move it DIRECTLY to a position 90 degrees away from the pointer. Either side, doesn't matter which, doesn't matter if you spin it backwards.
DO NOT MOVE IT THROUGH THE POINTER POSITION.
DO NOT MOVE IT THROUGH THE POSITION 180 OPPOSITE THE POINTER.
Now all 4 pistons are at mid-stroke and you can spin the camshaft any whichway you want.
3) I would turn the camshaft around & look for any large valve clearances. A bent valve will have excessive clearance to the rocker & cam lobe because it can't close as far as it used to. This may beobvious without even using a feeler gauge.
4) If you're lucky & none are bent you can continue...
Position the camshaft at it's timing marks.
5) Turn the crankshaft DIRECTY to it's mark, even if that means turning it backwards. It's OK for piston #1 & #4 to come to the top because those valves are closed. It's NOT OK for #2 & #3 to come to the top.
#4
04-02-2008, 10:35 PM
RE: If the timing belt is already broken!!
Just for thebenefit of anyone else who finds this thread by searching...
Earlier years didn't have timing marks on the crankshaft pulley. Marks were on the flywheel, but I don't know what year Honda switched over...
In that case, I'm not sure how you would accomplish #2 because you can't see the whole flywheel all at once.
Just for academic interest, maybe someone has an idea for that?
Earlier years didn't have timing marks on the crankshaft pulley. Marks were on the flywheel, but I don't know what year Honda switched over...
In that case, I'm not sure how you would accomplish #2 because you can't see the whole flywheel all at once.
Just for academic interest, maybe someone has an idea for that?
#5
05-13-2009, 06:25 PM
Timing belt jumped teeth
This is more for jim blake. You had answered me a year or so ago with this thread. I have now had the chance to get the covers off and look at this thing. The belt isn't broken. So I pulled the plugs and rotated the engine and lined up the marks. Everything seems to be lined up except for the cam shaft marks. According to the haynes manual, it says the cam shaft pulley should have the UP at 90 degrees. With the other marks pretty much on. the cam shaft is at about 89 or 88 degrees or 101 to 102 degrees depending on which way your triangle faces. Now, with that being off would that be enough to damage the valves and pistons or should I still look at those. Can I, when replacing the new belt just move that to 90 degrees? Again this is a 94 accord dx. Thanks again for your help.
#6
05-14-2009, 06:37 AM
The arrow is only approximate; it can be visibly off. The REAL timing marks are the little dimples out at the teeth of the cam sprocket. Those need to line up with the top edge of the back timing cover/shroud (#4 in the picture).
In any case, I'm pretty sure the cam timing would have to be off A LOT, before the pistons would hit the valves.
ps... I'm trying to remember the whole story. Why did you think the belt was broken? A common thing is for the belt to look OK, but the teeth are broken off around the crankshaft sprocket.
In any case, I'm pretty sure the cam timing would have to be off A LOT, before the pistons would hit the valves.
ps... I'm trying to remember the whole story. Why did you think the belt was broken? A common thing is for the belt to look OK, but the teeth are broken off around the crankshaft sprocket.
Last edited by JimBlake; 05-14-2009 at 06:40 AM.
#7
05-15-2009, 07:30 PM
Re: if the timing belt is already broken
Jim,
My daughter was driving the car and lives a few hours away. The timing belt had 90+K miles on it and I had asked her to get a quote on getting it changed. She called me one morning and had come to a stop sign in her neighborhood it's a mobile home park, so it's 15 mph and the car died. She tried to restart it and it wouldn't start. I just assumed that it was the timing belt, so I towed it back home. I have rotated the engine twice by hand as I missed the timing mark and the teeth are all in tact. I still am going to change the belts, though now if that camshaft mark lines up like you showed then I have to put it back together and start from scratch. It's got 220K on the car so probably could be a number of things, however it ran pretty good before this happened.
My daughter was driving the car and lives a few hours away. The timing belt had 90+K miles on it and I had asked her to get a quote on getting it changed. She called me one morning and had come to a stop sign in her neighborhood it's a mobile home park, so it's 15 mph and the car died. She tried to restart it and it wouldn't start. I just assumed that it was the timing belt, so I towed it back home. I have rotated the engine twice by hand as I missed the timing mark and the teeth are all in tact. I still am going to change the belts, though now if that camshaft mark lines up like you showed then I have to put it back together and start from scratch. It's got 220K on the car so probably could be a number of things, however it ran pretty good before this happened.
#8
05-15-2009, 11:38 PM
If the two marks on the camshaft line up with the back cover, then the cylinder head (valves, etc) are ok and the timing belt didn't cause the problem.
Try to determine if the problem is due to lack of spark or lack of fuel. Replace maintenance items if they are due (spark plugs, dist. cap, rotor, air filter, etc). A timing light should flash when hooked up to each spark plug wire if you are getting adequate spark.
For fuel, try to listen for the fuel pump to turn on for about 2 seconds when you turn the key to the II position. It happens during the clicks from the main fuel relay.
You can also try spraying starting fluid into the air intake (remove air filter top) and have someone try to start the car. If the car starts momentarily then stalls when you stop spraying, then there is likely a fuel delivery problem.
Try to determine if the problem is due to lack of spark or lack of fuel. Replace maintenance items if they are due (spark plugs, dist. cap, rotor, air filter, etc). A timing light should flash when hooked up to each spark plug wire if you are getting adequate spark.
For fuel, try to listen for the fuel pump to turn on for about 2 seconds when you turn the key to the II position. It happens during the clicks from the main fuel relay.
You can also try spraying starting fluid into the air intake (remove air filter top) and have someone try to start the car. If the car starts momentarily then stalls when you stop spraying, then there is likely a fuel delivery problem.
#9
05-17-2009, 07:48 PM
Re: if the timing belt is already broken
Sorry for the continued questions. I looked on the shroud and cannot see anything that resembles timing marks. Am I able to upload pictures for you to look at? I could send you a pic of this so we could figure this out. I just want to make sure so I can put this part back together and move on to more diagnosis. Thanks again for all your help.
#10
05-17-2009, 08:34 PM
See this post: https://www.hondaaccordforum.com/for...?t=3977&page=2
It is for a 92 accord, but it is pretty similar.
Here are the marks that I remember:
1. Crankshaft. When the harmonic balancer pulley is removed there are two sprockets. One of the sprockets has an arrow on it. When you pull off the outer one, the inside one has a dimple on one of the sprockets. For both those pulleys, there is an arrow stamped on the engine block.
2. Camshaft. The two marks are on the camshaft sprocket. Two of the sprockets have a thin line on the inside (valve side). Those two sprockets should line up with the timing belt cover. The picture with the three red arrows on the page I referenced has two arrows pointing to those sprockets.
3. Front balance shaft. There is a line on the shaft that sticks out from the engine. There is also an arrow stamped on the engine block.
4. The rear balance shaft. I got the rear balance shaft lined up by removing an access bolt behind the engine. A 1/4 inch drill bit fits perfectly in there. If the rear balance shaft is lined up the bit will slide in pretty far. I tested by putting the bit in when the car was not at TDC and marked the distance the bit traveled. When the car was at TDC, the bit went in much further. REMEMBER TO REMOVE THIS BIT WHEN YOU ARE FINISHED OR BAD THINGS WILL PROBABLY HAPPEN.
It is for a 92 accord, but it is pretty similar.
Here are the marks that I remember:
1. Crankshaft. When the harmonic balancer pulley is removed there are two sprockets. One of the sprockets has an arrow on it. When you pull off the outer one, the inside one has a dimple on one of the sprockets. For both those pulleys, there is an arrow stamped on the engine block.
2. Camshaft. The two marks are on the camshaft sprocket. Two of the sprockets have a thin line on the inside (valve side). Those two sprockets should line up with the timing belt cover. The picture with the three red arrows on the page I referenced has two arrows pointing to those sprockets.
3. Front balance shaft. There is a line on the shaft that sticks out from the engine. There is also an arrow stamped on the engine block.
4. The rear balance shaft. I got the rear balance shaft lined up by removing an access bolt behind the engine. A 1/4 inch drill bit fits perfectly in there. If the rear balance shaft is lined up the bit will slide in pretty far. I tested by putting the bit in when the car was not at TDC and marked the distance the bit traveled. When the car was at TDC, the bit went in much further. REMEMBER TO REMOVE THIS BIT WHEN YOU ARE FINISHED OR BAD THINGS WILL PROBABLY HAPPEN.