strsi

So today I was fixing up some final last minute things in order to get it ready to take it to Church so he can re-tune my car due to some new mods.

Once I was done i started it up & imeadiatly heard I vibrating noise. So I looked around & saw the timing belt shaking around on the cam gears as it was going over them. So I shut it down & checked the belt. Great condition, just very loose.

I had the timing belt changed no more then 5k miles ago, so Im not sure what's wrong. Is it possable that it just stretched from breaking in & needs to be tightened down or would this be a sign that my tensioner is going bad?

Im taking it to my mechanic tomorrow cuz I dont do timing belts, but I was just wondering what, if any, problems could have happened? Could it have jumped a tooth from being so loose, & if so what could this cause? Anything else?
BTW, I've never noticed it being that loose before nor have I heard the vibrating noise that I heard today. I shut the engine down as soon as I noticed the problem.

-Thanks

JDM_Ej

If your "mechanic" changed your belt, make sure he did the tensioner too. Other than that, the only thing I can think of is maybe its a B18 belt on a B16..?

JUN-DA6

it sounds like your tensioner is loose. I will just retighten the tensioner, but I don't suggest that you drive to your mechanic's shop. The best way is to ask your mechanic come to your car to do the retieten process. good luck!

Supahr_Ed

i had a faulty tensioner BOLT. The tensioner would get loose if i full throttle it. Otherwise it was tight.

90sedan

Ya, the tensioner is to blame.

strsi

yea, i had it towed there & he's looking at it now. hopefull it just loosened due to breaking in since its new. But if not then ur right, its probably going to need a new tensioner.

moto1320

There is no part of the breaking in process that should lead to any slack being generated in your belt. Some thing is wrong (breaking/broken) or a mistake was made on install.

2xtrme

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89-civic-DX &raquo;</TD></TR><TR><TD CLASS="quote">Ya, the tensioner is to blame.</TD></TR></TABLE>

How did you know that the tensioner bolt was bad? I hear all of this talk that a bad tensioner is causing the belt to get loose. The tensioner is just a pulley, so I don't see how bad bearings would cause it to loosen up. I see only three possibilities: 1) the belt wasn't tight enough in the first place (bad spring or bad install method), 2) the belt stretches over time, or 3) the tensioner pulley bolt allows the tensioner to move over time (bad bolt or improper torque). I've had this problem with OEM, Power Enterprise, and Toda belts. I'm considering swapping the tensioner spring with a stronger spring, or putting a toothed-washer on the tensioner pulley bolt to stop it from slipping. Any comments on these ideas?


Modified by 2xtrme at 2:38 AM 10/19/2005

smkngsr

if the tensioner is bad, it will definitely make some whining noise...tensioner is just a simple pulley and its being held up by a 14mm bolt...it can only go up and down...so since ur timing belt is kinda loose or wobbling during initial start up then u might want to pull the tensioner more because those slack on timing belt can easly affect ur timing on dyno...hope this helps

2quikmotorwerks

if the belt was installed to tight it could have stretched out the belt

2xtrme

I've decided to find a stronger tension spring to try on the tensioner pulley. I've measured the stock spring force at about 10lbs on a B-series motor and 5lbs on a D-series motor (~3" expanded length between tensioner pulley hole and spring pin). We measured the "coat hanger trick" at about 30lbs (give or take your personal bruteness). I'm going to order springs that will provide both a 20lb and 30lb spring force. I'll try the 20lb ones first to be conservative. If it doesn't whine like a supercharger, and the belt stays tight, that's the answer (no more inconsistent coat hanger trick). If it is still too loose, I'll try the 30lb spring and check for the whine. I'll post my results. Again, if anyone has any input on this, please speak up.


Modified by 2xtrme at 2:37 AM 10/19/2005

strsi

Wow i didn't realize this came back up to the top. But anyways the belt was tightened back up & has had no problems since. So i dont know what caused it, but its good now.

2xtrme

It looks like the springs I'm finding are going to be pretty sensitive to the extended length. Does someone out there have a B-series motor in their garage that they could measure the distance from the tensioner pulley spring hole to the far tangent of the spring pin coming from the block? A caliper measurement would be idea. Thanks!

Black R

pm vteckidd, he has a couple spare bseries motors around that he could measure out the length on.

fwiw, i replaced my tensioner and timing belt, spring and tensioner bolt recently.

if the tensioner doesn't have it's little arm in the eyelet, the angle will be all wrong and the belt will tighten up too loose...

A used tensioner spring (~35k miles on it) will have more slack than a brand new one.

And the spring does nothing once the tensioner is tightened/ torqued correctly.

2xtrme

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">
A used tensioner spring (~35k miles on it) will have more slack than a brand new one.

And the spring does nothing once the tensioner is tightened/ torqued correctly.</TD></TR></TABLE>

I just ordered a new spring and will measure it against my old one for tension force. That sounds like it could be the problem.

I know the spring isn't supposed to do anything once the tensioner pulley is torqued correctly, but if the increased engine torque and/or a bad bolt allow the tensioner to slip, then the extra spring load may help stop it from doing so. Regardless, at least the appropriate spring tension will eliminate the inaccuracy of the coat hanger trick (sometimes too tight & sometimes too loose).

Thanks for the input!

2xtrme

vteckid, or anyone else get a chance to measure the tensioner spring span on a B series motor?

I did buy a new spring, and found the tension to be a little higher on the new spring with my span approximation (ruler on an installed spring...kind of sketchy). I'd really like to know the force difference on a more precise span. Thanks!