In my other thread I detailed how we did a timing belt job on a 2004 D17 Civic. One of two things happened. Either driving through high water made the belt slip, which I doubt since the covers were dry, or we didn't install the tensioner correctly.

So, how do you correctly apply tension to the belt? The picture below shows the tensioner. All it has is a stupid thin metal allen wrench slot to "tighten" or loosen the tensioner. This is stupid. I'm used to cars having a jack bolt to tension a manual tensioner. Using an allen wrench and then tightening the main bolt down seems very poor technology.

Either way, how is this properly done?

 

From the FAQs


The old one may have passed it's service life. Most (but not all) people install a new one when doing the timing belt.

 

tension is applied by the spring that's hooked up to the tensioner.

i did my timing belt replacement by myself last week. you're supposed to hook up the spring then pull the pin to release tension onto the belt.

if you're reusing the old tensioner like i did, you're supposed to insert a hex key into the tensioner (there's a hole for it). using the hex wrench, turn the tensioner to release belt tension, then insert a coat hanger into it the tensioner. the problem i had was that the hex hole got stripped. i found it easier to just disconnect the spring, install the belt, then reinstall the spring to tension the belt. make sure you don't damage the spring or else it may snap off in the future. you can use a pair of plier to grip the spring, but you might want to wrap the plier w/ tape in order to prevent the spring from getting nicked.

 

http://adambovie.com/images/civic/tensionerhole.jpg

you can see the spring in this photo

 

Actually, we did buy a new tensioner to go with the belt.

We installed the tensioner exactly like you just said. We had the bolt loose, hooked the spring up. Tightened the bolt down, then pulled the pin out.

The belt was still tight when we pulled the car back apart after the belt slipped timing. So I don't understand what went wrong or how the belt slipped if we did it correctly.

When the belt jumped time, we had done exactly this DIY:
http://www.civicforums.com/forums/36...t-diy-2-a.html

 

are you sure the belt slipped? look at the crank shaft timing pulley, there is a belt guide thingy on it. did you reinstall it properly?

also, how deep was the puddle you drove through. are you sure you even have a timing related issue?

 

Bent valves, no compression, pulled the head and confirmed bent valves. Sorry, I've been so pissed about this I forgot to include some important details.

The water was about 1 foot deep. The timing belt cover was 100% dry on the inside.

 

did you have a cold air intake? did the car stall at all when you drove through the puddle?

 

sounds like hydrolock bro.

 

The belt is off at the start of the the instructions below.

See also the steps and photos at http://www.civicforums.com/forums/36...t-diy-2-a.html

 

The car died the day after driving in the puddle. No CAI on the car.

And that is the EXACT way we tensioned the belt, what you just posted.

This time we are having a shop guru come to the house for $$ to install the belt and tensioner itself. Forget screwing up again.

I can't believe I can make 450whp on a pump 1.8L car but can't do a timing belt job right on a daily driver. What crap. This hurt the ego very badly.

 

how long ago was the timing belt change done?

 

Week and a half ago. Drove excellent for that week and a half. No issues. Ran quiet, smooth, normal power, normal good fuel mileage.

The last weird thing was that it happened 2 miles after I got gas. I was pretty much on fumes when I got gas.

 

so then you checked the timing belt and found it to be off by one tooth?

 

Not just one tooth, about 10 teeth. It slipped big time.

No signs of damage to the belt like missing teeth or separation. Plus it is a brand new Conti belt.

 

check the belt guide plate thingy on the crankshaft timing belt pulley. it's the thing made of stamped sheetmetal. it sits between the pulley and the engine block and there's a specific direction that it needs to be facing (but can be installed the wrong way).

 

This whole scenario kinda freaks me out because I'm doing my timing belt this weekend on my d17. I will take pictures and upload when complete...

 

When you guys changed your tensioner did you also replace the spring and bolt?

 

For? We have a DIY which is loaded with pictures. I don't know why you'd bother going through the trouble.

 

Thanks! I am still learning the forum AND I have limited time.

Anyway, I was thinking more about this thread and I was wondering: after you set the tensioner, did you give the set screw a snug turn (not toooo tight or you'll break it)? Because I am willing to bet that if you put a brand new tensioner in there, that the spring got loose somehow...either from engine vibration or hydraulic pressure. Right before this happened were you hard on the pedal? Because if it backs off the slide adjuster it will suck in, snap open and then try to snap back closed which may have caused your ten teeth jump.