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?

 

[sjwelna]

I dunno about you guys, but my timing belt feels REAL loose, it shouldn't be able to get pushed down like that. What should I do about it? Do you think the tensioner went bad? I JUST had this replace by a dealership at 57K and i'm at about 69500 right now. I told them to do the tensioner, but I don't think they did it, if I remember correctly they were like "well the tensioner is fine..."

What can I do about this, I don't think it's jumped timing, but I don't have a timing light to check.

Opinions?

BTW...My motor mounts were toast, here's a shot of the one from by the timing belt.... notice the nice long crack that went through the whole mount, it was really brittle too, drill got rid of that stuff with the quickness...

 

[rowlex]

two things you can do, and do one of them NOW. Don't mess around with timing belt shit.

Option 1: take it to the dealership, see if they will fix it for free, if not pay them to.

Option 2: Print the timing belt vfaq, pull your timing belt cover off, drop the tensioner, and replace it. Retighten timing belt/etc.

Goodluck, I'd avoid driving it much, if you watch the belt as you rev the engine, (mine has very little play - acceptable) I can watch it "flap" up and down, and mine has very little play...

 

[sjwelna]

Yeah, see, that's the thing, I'm now living 1300 miles away from that dealer that did the work. Looks like I may have to pay some one to do the tensioner. Is it really that hard, or is it just a PITA? I really don't want to mess with timing belt stuff, I have enough problems with everything else. Don't want to mess something up.

Suggestions?

-Steve

 

[HighPsi92GST]

going by what you just said, take it somewhere to get it done...and do so soon

 

[TwoLiterV8Eater]

In all honesty, that amount of slack looks normal for a car that hasnt been started in a day or so. Once you start the car the oil pressure will fill the lifters and the slack will go away. I don't think anything is wrong with it. But if you are feeling adventurous, remove the accesory pullies and lower timing belt cover. Check the amount of distance the tensionor rod is protruding from the tensionor and compare it to stock specs. It shouldnt take more than an hour, especially if you still have the motor mount out of the way.

 

[rowlex]

In all honesty, that amount of slack looks normal for a car that hasnt been started in a day or so. Once you start the car the oil pressure will fill the lifters and the slack will go away. I don't think anything is wrong with it. But if you are feeling adventurous, remove the accesory pullies and lower timing belt cover. Check the amount of distance the tensionor rod is protruding from the tensionor and compare it to stock specs. It shouldnt take more than an hour, especially if you still have the motor mount out of the way.

Mine has never had that much slack in it, even after 8 months of not being run. how does the slack go away?? just because the lifters fill with oil?? The lifters dont push the camshafts upward at all. That belt is gonna be flappin up and down when he starts it.

If you want to prove this, start it up, have someone rev the engine while you watch the belt from the side (inbetween camshafts). Or you can watch and rev it up yourself by pushing the throttle cable behind the intake manifold. That slack doesn't go away.

If you have another car you can use as a daily driver I would suggest doing the work yourself. It will REALLY get you aquainted with your engine, the vfaq has step-by-step instructions on how to do everything, follow it to a T and I dont think you will have a problem withi t.

 

[HighPsi92GST]

Once you start the car the oil pressure will fill the lifters and the slack will go away. .

WTF? they cant move more then like 0.001 inch because thats about all the clearance they have in the bearings.

 

[sjwelna]

Even though the car has sat overnight, it was like that last night about 4 hours after I got back from driving for 3 hours. I think the tensioner is bad. I think I may be able to get it replaced under warranty, seeing as it's been less than 12 months since the work was done for the timing belt. My invoice says "replace belt tensioners" under the work to be done, but there was no charge for a tensioner as a part. We'll see if I can't get this fixed asap.

-Steve

 

[truwarrior]

Mine like that sometimes too. Looks normal to me but im not a mechanic

 

[sjwelna]

PS..... HOW THE HELL DO I GET THE TRANNY MOTOR MOUNT OUT??? Do I have to chop the tops of the bolts off of the tranny so that it will clear????

-Steve

 

[sjwelna]

Follow up: I got the tranny mount out, had to take the bolt out of the front mount, then let the whole tranny and everything drop down, then take my dremel and grind the hell out of the tops of the two pointy bolts closest to the passenger side fender, then it just slid right out.

Word of advice when doing prothanes: when you put in the full replacement mounts on the drivers side by the timing belt and the tranny one, spray some kind of lube on the mount so it slides in better, i wrestled with the t-belt one for a while, then tried that and it helped a lot.

Prothanes are in, I didn't do the rear for lack of time, got the SBR mani on and my exaust leaks fixed, so all in all it was a productive day.

-Steve

 

[Defiant]

That slack is normal for the timing belt. When stopped, the cams are being pushed on by the valve springs. When it stops at just the right point, the intake will be being forced CCW, while the exhaust is being forced CW, making for the slack you found. The slack's taken up by the crank before the engine fires, but it's also what's hardest on the belt, and why it's so common for a belt to fail at startup, shutoff, or during idle.

 

[RoasT BeeF]

You cannot check the belts tension between the cams because of what Defiant said. The only way you are really going to know if its out of tension is if you remove the lower timing belt cover and check it there.

Inbetween the cams means nothing.

 

[eclpsegsx12]

turn it over by hand and the belt will lose slack

 

[sjwelna]

I'll trust defiant's infinite wisdom on this one, thanks guys. Now if i could just fish that damn spacer for the fuel rail out from under the intake manifold I'll be set ......where's my three finger grabber tool.......

-Steve

 

[1fast97gsx]

yea the belt is normal .. trust me I got worried too when I saw that on mine so I read up on it as well. If you go start your car now and shut it off and right away check slack again then it should be pretty tight. Check again a day later without starting and it'll be loose again ... that's normal.

 

[loreak]

yeah even if it was bad you cant really tell by the top part, because even if the bottom is loose the top wont change because the teeth are holding the tension between those pulleys, the place you loose tension and it skips would be on the bottom

i had my tbelt skip a few teeth and the top seemd fine, but when i took it apart the bottom was very loose, i have 1dsm, 4 heads, and 2 motors , and like a bajillion parts, ive done everything from skip teeth, to bend valves, to strip the teeth right off a belt, to dropping a valve and getting it lodged in the top of the piston, all in less then a year, i think thats gotta be some kind of record

 

[pickens]

Old post... but I thought I would add that my t-belt goes loose on occassion when I shut the car off and then tightens right up when I start it again. Definately scary but I guess it may not be a problem...right?

 

[Defiant]

Old post... but I thought I would add that my t-belt goes loose on occassion when I shut the car off and then tightens right up when I start it again. Definately scary but I guess it may not be a problem...right?

They all do:

http://www.dsmtuners.com/forums/showthread.php?t=141441&highlight=timing+belt

 

[50trimtsi]

hey guys i have a quick question. does this look like there is enough tension on my timing belt? the pics show me push and pull on it and one just as it sits. look ok to you guys?

 

[ACKERSON]

That isn't where you are supposed to check the tension, but either way it is way off. Did you just install that t-belt?

 

[50trimtsi]

shop installed it, i took it back cuz it felt kinda loose they checked it and said it was fine. it seems to be tightening up though!! the more i drive it?!?!

 

[Defiant]

Post 13:

http://www.dsmtuners.com/forums/showthread.php?t=141441

 

[huafist]

Defiant's post answers the question. Nothing is wrong, it's normal to have slack between the cam gears. The crank will take care of it at startup.

 

[50trimtsi]

yup i agree now to. I also think that slack depends on the cam position as well.? anyway it seems to actually be a little tighter now as well. I appreciate all the responses and help on this subject. It was very nice of everyone to take the time to help me out. Thanks again everybody. Matt