Timing Belt Slack Explained [Merged 6-7] loose cam sag sagging sprockets gears

[defbear]

I was just wondering if its normal for the timing belt to have some slack after its been sitting over night. I have been checking it for the past few days. When the car has just been shut off and for a few hours after its nice and tight with virtually no play. But in the morning when I check it there is some, not alot, but some play. More than just after its been driven. The timing belt and tensioner were replaced about 2000 miles ago. Anyone have any ideas?

 

[v8s_are_slow]

Do you mind explaining exactly how you adjusted the tensioner? I don't mean, did you perform it the way that's listed in the manual or not, but how did you do it in your own words. I mean, not to say you don't know what you're doing but everyone makes mistakes. It DEFINATEYLY seems as though the tension isn't right on that belt. It definately seems too loose. Regardless of where the timing marks line up, there's still some slack in the belt.

I go by the VFAQ but I use a 5/32nd drill bit for the tensioner cause I don't have any metrics and the 5/32nd is pretty close. And until you get it right, you definately shouldn't drive it if it looks like that unless you like pulling the head for a valve job.

 

[steve]

I don't mean to sound like a jerk but I'm not stupid...I know how to line up the timing marks and they are all perfect.

Nobody said your stupid but we can't help you if you won't provide the information we need to see why this is happening. It's pretty obvious that things aren't perfect or the thread wouldn't exist much less be 10 days old with no solution.

Since I've somehow offended you I'll move along. There are plenty of other questions.

Steve

 

[GVR4592]

I don't mean to sound like a jerk but I'm not stupid...I know how to line up the timing marks and they are all perfect. I checked again yesterday when I put the new tensioner in. Everything is put on perfectly, the belt is the right one straight from slowboy and I have double checked part numbers on everything. Every time I notice the belt loosening I am able to turn the intake cam gear a couple degrees clockwise. I don't know if it should be able to move this much because the exhaust gear is always perfectly tight. Now I am thinking that maybe one of the lifters is not working and not keeping the cam still. As soon as I turn the gear a couple degrees it tightens right back up perfectly. And incase I didn't clarify, the belt is not off a tooth. I took my precious time when putting the belt on and went perfectly by the factory service manual. I'm really thinking it's something in the head. Does that sound right? Maybe a lifter isn't working? They are brand new revised lifters so they should be fine.

What valvesprings do you have?

 

[Old Mitsu Tech]

The timing belt was either not set up right in the beginning or the auto tensioner has lost its ability to hold tension in the belt. Either way it needs to be done over. Irregardless of what may or may not have been done in the beginning. Just a month ago and I had to do a do-over myself. Happens to all of us sooner or later. Timing marks lined up is only a part of the equation. Setting the preliminary tension is also critical.

 

[jonheslop]

The auto tensioner is only a day old so I know it's good. I have replaced every single timing component with factory parts including the arm that the tensioner pulley sits on. I have SI dual valve springs for whoever asked that question. The tension on the tensioner pulley is correct and the gap on the auto tensioner is correct. I've checked them both many times.

 

[v8s_are_slow]

Okay, I'll ask again (you're the one needing the help on this, not me), HOW exactly did ya set it up? You say the tension and all was done correctly. Maybe you "think" you did it correctly but didn't. I/we have no way of knowing cause you haven't told us how you did it yet. What tools did you use to set the tension and how? If you can't explain it, at least get us some better pictures or something. I mean every freakin part as it's installed.

 

[sleepy98gsx]

I'm sure you all are sick of hearing about the loose timing belts but here's a question that i haven't seen answered..usually it should tighten back up after starting right? well here's the case with mine..it does tighten up pretty nicely, but not until after i let it warm up completely and then drive it, after driving it, it is then tight..When i start it in the morning it is kinda flappy (you can here it kinda vibrate on the tensioner pulley), but it runs strong when driving and again, it tightens itself up, it just takes a short drive around the block..time for a new tensioner or a new belt maybe? even though they're both somewhat low mileage? the belt has a little more slack than usual too, any tips that could help?

also, i've heard putting any kind of belt besides a mitsubishi belt on is a bad idea so i should use the mitsu belt, but all other mitsu belts are made by Dayco and i work at an auto parts store that sells only dayco..taking opinions, thanks guys!

Chris

 

[DIRQUIN]

It wouldn't hurt to put a new tentioner and belt on. You work at a parts house so you get the parts preety cheap. After that if it still does it, and not causing a problem I would just keep an eye on it. Mine does the same thing, and I've seen many other cars do it as well. As long as its not realy looose you should be OK. I have only run mitsu timming belts, but I thing I'm going to try a greddy next time. We'll see if theres a difference.

 

[boostedinaz]

Only use a Mitsu belt or the kevlar belts if you feel the need.

Were are you looking when you see the floppiness? I hope it isn't between the cam gears with the cover off.

 

[sleepy98gsx]

the worst is between the cams and i know you're not supposed to check there, but it scares me because it's kinda loose on the first two or three teeth of the exhaust cam, when it's cold and it is pretty bad it is kinda flappy looking down below the exhaust cam to the tensioner pulley..when i did check it on the cams when i make it tight on the teeth the whole way it kinda puts a VERY small hump in the belt at the top there..

 

[boostedinaz]

the worst is between the cams and i know you're not supposed to check there, but it scares me because it's kinda loose on the first two or three teeth of the exhaust cam, when it's cold and it is pretty bad it is kinda flappy looking down below the exhaust cam to the tensioner pulley..when i did check it on the cams when i make it tight on the teeth the whole way it kinda puts a VERY small hump in the belt at the top there..

The only way to check tension is buy setting up the tensioner according to specs. If the auto tensioner is out of spec replace it. You will always have some odd looking things going on with the cam gears as the valve springs put pressure on the lobes and can "push" the cams in either direction leading to slack or tension on either side.

If you are really worried then pull the cover off and check for proper tension.

 

[Wicked96GS-T]

I swear we need a sticky for "Slack between your cam gears?." It is like this on my GSX with a brand new belt/tensioner/pulleys, and it is completely NORMAL. I don't understand why people continue to ask about it when Defiant answered within the first 10 posts that it is normal. Leave it alone, or put your timing cover back on so it doesn't scare you.

 

[sleepy98gsx]

ok, well it turns out i do need a new tensioner so i guess i wasn't just being paranoid, thanks for the help guys..

Chris

 

[Jon Lane]

Whew. Glad that's finally over with...

I hope.

By the way, about belts expanding when they warm up, they don't. Rubber contracts as it heats. This could mean that a tight belt at shut-off is a slightly looser belt six hours later. Counter intuitive, but there you have it.

 

[TurboBlue]

I'm having a repeating problem with my timing belt. Everytime I do it, I tension it correctly, I torque Bolts, I install new belt, tensioner, tensioner pulley and an idler pulley. When it was done, the tension of the belt between the cam gears was very nice. It was tight and there wasnt much deflection. But now, I once again notice the belt is lose between the cam gears and has been rubbing on the cover, enough to show the inner threads of the belt. Can anyone please help me?

 

[Eclipsethis90]

Did you let your tensioner fully extend? If so it will damage the unit. When you released the tensioner after setting the torque, did you let the tensioner rest fully for 15 min before rotating the crank 6 times to recheck?
If you did everything correctly, my only thought is you have a bogus belt. Did you use a Mitsu?

 

[daren_p]

Did you do the above, then check to make sure the auto tensioner is within spec? Did you make sure to replace the cover bolts in their correct locations as they are different lengths & can wear on the belt if put in the wrong spot. As for the tension between the cam gears how much do you have? You'd be surprised how much is acceptable as depending on how the cams gears stop when you shut the car off there can be quite abit of slack. Normally this is taken back up when the car is started.

 

[TurboBlue]

I did let the tensioner sit, and rotated the crank six times. The tensioner was in spec after it was extended, I even used the shank of a drill bit like the book said. As far as slack inbetween the cam gears, i'd say there is 1/2 to 3/4 inches from pushed down to pulled up. But the most concerning part is the edges wearing, and there is some belt dust inside the cover. And the cover is new aluminum, so i know its new dust. As far as the belt type, its a Gates from NAPA. I'm just entirely confused.

Should i try letting the car run and shut it off again to try the tension in another spot? I'm also going to rotate the motor and make sure it didnt jump on me. If it didnt, then i guess its just time to tear it down and check everything...

As far as cover bolts...i really dont know. I guess its time to buy a new cover and bolt set for it, as its 13 years old and been through a lot of owners....

 

[qtxdevilz]

I did let the tensioner sit, and rotated the crank six times. The tensioner was in spec after it was extended, I even used the shank of a drill bit like the book said. As far as slack inbetween the cam gears, i'd say there is 1/2 to 3/4 inches from pushed down to pulled up. But the most concerning part is the edges wearing, and there is some belt dust inside the cover. And the cover is new aluminum, so i know its new dust. As far as the belt type, its a Gates from NAPA. I'm just entirely confused.

Should i try letting the car run and shut it off again to try the tension in another spot? I'm also going to rotate the motor and make sure it didnt jump on me. If it didnt, then i guess its just time to tear it down and check everything...

As far as cover bolts...i really dont know. I guess its time to buy a new cover and bolt set for it, as its 13 years old and been through a lot of owners....

use an oem belt or one of those kevlar timing belts made by power enterprise and greddy...

and what do you mean by the cover is new aluminum...the timing covers are suppose to be plastic...

 

[TurboBlue]

I know they are supposed to be plastic, but I got bored and made one out of aluminum, i'll post a picture tomorrow when i get back to the car....

 

[Eclipsethis90]

From what i am reading it sounds like your cover is too small when you tighten your bolts down fully. Still have the OEM cover? Give that a shot before dismantling the whole set again. If it continues replace the belt with the two suggested in an earlier response.

 

[1gdsmraider]

You say the belt is rubbing? Well, I think when you reinstalled the pulleys you reversed the tensioner pulley..it is possible and I have seen it done many times. The lip on the tensioner pulley helps keep the belt off the items protruding from the block, without it, the belt tends to walk inwards eating your belt.

 

[qtxdevilz]

You say the belt is rubbing? Well, I think when you reinstalled the pulleys you reversed the tensioner pulley..it is possible and I have seen it done many times. The lip on the tensioner pulley helps keep the belt off the items protruding from the block, without it, the belt tends to walk inwards eating your belt.

he is talking about the timing belt...that has nothing to do with the pulley...maybe there is a flaw in your timing belt cover since you made it yourself...put an oem one back on there along with a decent timing belt and see what happens...

 

[1gdsmraider]

he is talking about the timing belt...that has nothing to do with the pulley...maybe there is a flaw in your timing belt cover since you made it yourself...put an oem one back on there along with a decent timing belt and see what happens...

His words

Everytime I do it, I tension it correctly, I torque Bolts, I install new belt, tensioner, tensioner pulley and an idler pulley.

There is a possiblity it is the cover, there is a possiblity of the pulley being installed backwards.

 

[TurboBlue]

I know thenew cover isnt rubbing, since there is no marks on the inside of it, only belt dust. And i can guarantee the tensioner pully isnt on backwards because well...im not stupid. The thing i am hoping for now, is that the crappy Gates belt stretched. Like I said before...im still sunre if the motor jumped timing, i'll find that out tomorrow, and even then, i guess i just have to tear down and investigate.

I really dont want to drive the car, due to the fact it may break/jump, and then I will be in a whole new world of hurt..

Thank you everyone for your help...if anything more gets thought of, i will gladly accept any ideas and take them into consideration.