James89DX

2004 DX, d17a1 I believe

This is a friend's car, and I've yet to look at it, but it sure sounds like her car jumped timing. She was in a parking lot and it just died and wouldn't restart. She was able to get the timing cover off and send me pictures showing the belt isn't snapped (though it is pretty damaged, it's gouged in the middle - tensioner maybe?). Here:




She said it's not loose, either, but of course that's a relative term. I'm hoping there is no valve damage considering she was basically at idle when it happened and I've read that the a1's are less susceptible to valve damage than the a2s, though I don't know if this is true.

Anyway, I'm planning to head over there this weekend to attempt to fix it.

I would just like to make sure I understand how to get both the cam and crank aligned properly without damaging the valves in the process. I've done several timing belt jobs on Civics over the years but never in this situation where it's potentially a tooth or two off going into it. I've been doing some reading online but I'm not 100% confident in my understanding.

Here is what I'm thinking and welcome input/corrections/confirmation -

1) Assuming it did jump time - remove belt, rotate the cam gear counter-clockwise to TDC ("UP" on the sprocket facing upwards, marks on sides of the sprocket even with the head)

2) Rotate crank pulley counter-clockwise until notch on crank sprocket corresponds to arrow on block.

**This is what I'm most unsure about - I've read it needs to be at TDC on the number 1 cylinder and have read about people using the dipstick down the spark plug holes to figure out when the number 1 cylinder is at its highest point. I'm not sure if I need to do one or both of these (or if they're the same thing). When the crank pulley sprocket lines up with the arrow on the block does THIS indicate the number 1 cylinder is at its highest point? Or do I need to rotate the crank pulley until the notch matches the arrow AND the number 1 piston is at its highest point (meaning it could take several revolutions to achieve this desired combination?)


3) Proceed to do timing belt install per normal


I appreciate any help/input/clarifications!

Fliptard

Get a New timing belt, water pump tensoner kit. Pull all timing covers off. The timing crank pully will have a mark, and the oil pump will have an arrow. line those up. On the cam gear there should be 2 dots on either side. And some type of mark that is the "UP" position inbetween the dots. Point that mark up and align the 2 dots either with a mark on part of the timing cover or so that they align with the top of the head. Rotate engine by hand a few times and put the crank pully back at it's mark and verify everything is still where it should be. Tighten the tensoner and bolt everything back together

anibis

Well the "UP" is straight down it looks like so cylinder #4 should be at TDC. The crank rotates 2x for every revolution of the cam which means the crank should be close to TDC if she only skipped a couple teeth. Just look at the marks and move it whichever direction is the shortest distance and you should be good.

I get what your sayin, don't want to bend the valves trying to get it re-timed. I've never had to do this either so I'm not 100% sure, it makes sense though. Just look at the marks when you get everything apart, the crank should be close.

To get the cam back to tdc ("UP" mark up) you would have to move the cam with the crank and that could be bad.

The car will usually run (like crap) if it skips 1 tooth but no more.

anibis

Double post.

James89DX

Fliptard - I will be doing the belt, tensioner, water pump etc.

I know that I'm supposed to line the cam gear up with the head and the crank sprocket with the arrow. I guess I chose my wording poorly in the first post but I'm not sure how else to ask it.

I'm mainly unsure as to whether the crank pulley notch lined up with the arrow = TDC at number 1 piston. OR could it be TDC of the number 2 piston, or number 3 piston, or number 4 piston. Meaning I would theoretically possibly have to rotate the crank several revolutions to get the proper combination of marks lined up AND number 1 piston at TDC. Does that make sense what I'm asking?

I feel I'm over complicating this but I just want to make sure.

anibis

When cylinder #1 is at TDC so is cylinder #4, same with #2 and #3. So if the "UP" is at the bottom, the #1 cylinder should be close to TDC if it only skipped a couple teeth.

Take it apart and look at the marks, if they're close move whichever direction gets the marks lined up in the shortest distance. Don't worry if you have to turn the motor clockwise, it will be fine. You need to get it in time with as little movement as possible, if it's far enough out of time and you rotate the crank until the cam mark is "UP" you risk bending valves.

If it skipped more it will be further off and the valves may already be bent, you won't know until you get it apart.

James89DX

Well I went and checked it out Saturday. The tensioner failed, and the tensioner spring had broken, shredded the timing belt, and the spring disintegrated itself down into the crank snout area. It chewed up the crank position sensor pretty bad and had me worried it was damaged beyond repair because I read about how sensitive they are to such an extent that you can't even unplug the harness. It took me forever to dig out all the bits of spring and belt material.

The belt was still on but was very loose and literally held together by one little strand of belt - literally hanging together by a figurative hair.

I had a hard time getting the cam to TDC. It seemed very stiff and didn't want to turn in ANY direction more than about 1/8 without an alarming amount of resistance. I ended up using the dipstick through the spark plug holes to determine the relative height of the pistons and turned the crank, then measured over and over to try find a position where none of the pistons were really high. I don't know if that helped any but I eventually fumbled around enough and got the cam to TDC.

Then I did the timing belt per the FSM and cycled through several times to ensure both cam and crank TDC marks stayed lined up. I also replaced the crank seal, the water pump, spark plugs, valve cover gasket, and air filter. Put it all back together and it fired right up and runs perfect. Quite a relief