I think my timing belt may be off a notch on the cam. Car seems to be noisy (valve clatter) that doesn't go away after warm up. Valve adjustment seems to be on the money. Also, I changed the timing belt about 15K miles ago, and after I did it, I noticed that the timing had advanced. I moved the distributor back to 12 degrees BTDC.

So my questions: 1) If I remove the top half of the timing belt cover, can I loosen the tensioner and wiggle the belt on and off at the camshaft without yankin' the crank pulley, belts, and the rest of it? 2) How does the TDC mark on the crank pulley relate to the marks on the camshaft gear (how should it all line up)?

Thanks for any help.

Boy! Am I gald you asked that!

While I had the top cover off when replacing a water pump the other day, I noticed my belt had slippet about 8"......

The Contitech belt I put on 20K ago has alignment lines on it. I am sure I used these to match up with the timing markd onthe sprockets. Now I see the top sprocket timing mark is half way between two single lines on the belt!

I seem to remember, though, it is the pointing of the marks on the sprockets relative each other that's critical, not the lines of the belts.

nevertheless, I did gfigure that the belt had slipped. And this even though I did the 500-600 mile retensioning.

Come to think of it, my valves are clattering oudly, too!

Well, I checked my timing belt on Saturday by removing the top timing belt cover and found that the mark on the cam lined up perfectly with the TDC mark on the crank pulley. Which made me think I could eliminate that possibility from my list. One of the guys contacted me off list and said that sometimes the TDC cover marks are off and that the only true way is to use the marks on the block. Which means yanking it apart. Crap!

I think I might just move to the rubber dampers for the valves and assume that the marks on the timing cover are correct.

As my wife likes to say..."It's not just a car, it's a second job."

/// It can be done. I don't have your mod so I don't know what else you have in front of the engine.

To get room remove the shroud and radiator.

After you loosen the timing cover and bend it forward you will be able to tell if it will work.

Of course the crank must be at TDC, the distributor at number one position, and if the cam is on correctly the notch on the head will line up with the cam gear mark. The timing marks on the belt WILL NOT be correctly placed. They only line up after a certain number of turns of the crank. What ever that number of turns is,the marks only line up on that cycle.

If you determine to go ahead,mark the distributor gear and the front of the engine since you probably won't be able to see the arrow on the gear and will guess at the 4 o'lock position for it. You use those added marks to put it back where it wls.

If there is any slack you turn the cam back slightly to catch the correct belt tooth then return it to the marked position. All belt slack MUST be on the adjuster side.

That's the information I needed. Thanks. I thought the allignment of the cam gear and the crank pulley was that way, but I needed the verification. I'm not worried about the marks on the timing belt right now. If I do decide to go in, I'll change out the belt. At least now I can determine whether or not the sucker's out of sync without ripping it down or, as Rene suggested, bad rubber dampers.

Thanks to all of you for the responses.

Hmmmm.

After reading This thread, what I saw could have been the belt "in-between" its lining up at certain times with the marks on the sprockets (as when intstalled)

It's true, I was observing the positions of those lines on the blet only after I turned the crank several times to put tension on the belt in order to inspect/adjust the tensioner (while I had easy access during the water pump change out)

Assuming the timing is correct, valve chatter can be caused by worn out rubber dampeners on the valves. Even if the valve adjustment is correct, it will still tick. I was advised to replace them when doing a valve adjustment.

Rene

Can tose be replaced from above, as when adjusting the valve clearances? Or, does the head have to come off, as a more serious operation?

They are located under those upsidedown cups. Are they called lifters? Anyways, those can be pulled off and below are the silencers. I don't remeber if they are on all the valves, perharps only the intake valves, but Bentleys should be able to tell you that.

Rene

I had heard that also. Once I verify that the timing is correct, I'll try the rubber dampers. Thanks Rene.

Neal,

You want the crank sprocket and the cam sprocket dead nuts on the marks when you install a timing belt. If the cam is slightly off from the crank, the cam timing will be slightly advanced or retarded. For these engines, lined up seemed to work best. The distributor sprocket can be slightly off (like a tooth or tooth and a half) as the timing can be adjusted by rotating the dist. to 12 BTDC. I think your into opening it up because once you loosen the tensioner, everything can move and you might not realize it. Good luck.

Hi Mike. Thanks for the input. Do you know how the mark on the camshaft gear relates to the mark on the crankshaft pulley? If I have the top of the timing belt cover off, I'll be able to see the marks on the camshaft gear, and the crank pulley, but not any marks on the crank gear.

I know I might have to open it all up, but if I can do it just by taking the top half of the timing cover off, I'll be a very happy boy.

You can - I've done this. But I don't recommend it. I ended up having to tear everything down anyway to put it all back the way it should be.

Problems: Which way are you going to move the gear? Are you *sure* it's the cam gear that is off a tooth? After a few miles, the alignment marks aren't *anywhere* near where they should be, so it's all guesswork.

Changing the belt only took me an hour and a half the last time I had to do it. I would suggest grabbing a new belt (with new index marks) and installing it with everything lined up as it should be. Yes, it's a pain in the arse. But - wouldn't you rather do it ONCE than three times?

If you have your heart set on it, though... This is what I did:

Take the top of the belt cover off. Loosen the tensioner. Keep the 17mm socket/wrench handy. From the driver's side, pull on the belt, compressing the tensioner - keep pressure on and tighten the tensioner down. Now you have room to move the gears about - but be careful of the distributor gear and crank gear - if you move the belt on those, you'll have to tear it all down anyway. When you've got it all lined up like you want it, loosen the tensioner and it will pop the belt back into place. Turn the crank a 1/4 turn or two to make sure the belt is seated and tighten the tensioner back down.

I'd give the car a test start at that point to make sure it is running the way you want it.

Good luck!

Seems to me the belt would jump in the direction the crank pulls it....

As you look at it from the front, this could be closkwise.

So, If the belt is going to jump due to a loose tensioner, day, I firgure it would hop left to right over the top sprocket. With the cramk pulling clockwise, slack would be to the left (tensionerI) side. Would hop up and over the top.

Well, right now, I don't know which way to move the gear. I've got to take off the top half of the timing cover to see if things are lined up first. If the belt is misaligned, does it really matter where I make the correction? If I get the crank to TDC, and the cam gear is off by a tooth, I should be able to move the belt one notch on the cam gear and have everything be fine as long as I can still adjust my distributor to the proper timing. Or is my logic flawed somehow?

It sounds like the simple method may end up being the hard method. I guess I'll have to open it up and see what my options are.

Thanks for replying Richard.

"It sounds like the simple method may end up being the hard method. I guess I'll have to open it up and see what my options are."

At the risk of sounding oh-too-cheesy, don't fall victim to:

There's never time to do it right but there's always time to do it twice.