So I'm on Honda-tech, and I'm frustrated about my Honda, so I figured why not start a thread ranting about what happened.

First off, I have a jdm 98 spec type R motor, stock on the inside. It hasn't been in the car long, and I've already had a couple of stupid issues that have kept me from being able to fully enjoy the car. First, I had a timing cover bolt come loose behind the cover and chew up the belt, causing it to loose tension and jump a couple of teeth. I tore into it, pulled the head to assess the damage, and luckily no valves touched the pistons so I simply replaced the head gasket, put it back together with a new belt, and all was well. Then I developed a leaky oil pan even though I replaced the gasket before I installed the motor, so I figured it was time to change the gasket again. Finished that about a week and a half back and I thought it was good, but turns out this gasket didn't take either so I'm going to have to replace it again. Relatively minor, but sort of an inconvenience none the less as this will be my third pan gasket for this motor and I've NEVER had a problem with fixing a leaky pan after the first gasket replacement.

Anyways, I decided to take it on a little half hour road trip today to enjoy the car a bit since I haven't been driving it much lately. The trip started off good, the car was running great, as it has been since I replaced everything after the timing belt situation. I wasn't beating on the car by any means, just cruising at about 60 on the highway and the motor was feeling strong. I thought I had heard something funny (although I can no longer recollect what I thought I had heard, or if I had truly heard anything) so I decided to take my foot off the gas and press the clutch in to take away some of the exhaust noise when all of a sudden the car just shut off. "That's odd", I thought. Coasting with my foot on the clutch I decided to start it back up. The motor seemed to turn over fine, and it went to fire up, but hesitated and didn't start up. So I pulled off of the highway into a near parking lot, came to a stop, and tried to start it again. I heard the starter turn then I heard a loud CLUNK so I let off the key, instantly I knew that something was not good.

Upon getting out of the car and popping the hood my girlfriend noted that something smelled bad, like burnt vacuum cleaner, is how she put it. Lifting the hood I could see a bit of smoke rolling out of the timing cover area...I didn't even want to attempt to start it again. We were about 25 minutes from home, roughly ten from our destination, so I called a tow truck to come pick us up and get the car home. Realistically I didn't even want to work on it at all because of my frustration, but I assumed that something happened to the timing belt again and it more then likely jumped timing again. I pulled the VC off, and the upper timing cover, and low and behold the timing belt was a bit chewed up again. I looked at the belt on the cam gears and it was pushed back towards the cams as opposed to being centered on the cam gears like it should have been. Because of this, there was traces of dusty rubber belt shreds around the cam gears and behind the timing cover. Awesome.

I looked at the cam gears to see if they were lined up any more and lets just say that the motor jumped timing...more than a little. I'll have to post a picture to better illustrate what I mean, BUT, the intake cam was completely 180 from the exhaust cam and the timing belt teeth were not really lined up with the cam gear teeth at all.

I'm assuming that this disaster probably caused some damage to the valves this time, unlike the other time where I got extremely lucky. I guess I just hope that if there was contact, that it was only a couple of the valves that suffered and not a piston or something. I'm starting to seriously believe that this motor may be cursed. Realistically its a very strong motor, relatively young with good compression numbers (after first timing belt incident). It doesn't seem to burn oil or smoke at all, even for a b-series.

Sorry for the super long story but it's been playing over in my head for a few hours now and I needed to share the ranting frustration. Also, I guess I'm sort of looking for a bit of insight as to why it may of jumped timing the way that it did. The tensioner is brand new with maybe 400 miles on it. Also even after this happened there was still tension on the belt, although it noticeably jumped teeth. I wonder what may of caused the belt to walk back towards the cams and rub against the inner timing cover. Too much tension possibly? Normally I'm pretty careful with my work and have never had a timing belt problem before (doesn't mean I didn't make a mistake now though). Either way, end rant, for now.

 

It just seems like the T belt was improperly installed.

 

While that is very likely the case, ikm curious as to specifically what may of been done wrong to cause it to walk back towards the inner cover like that and get shredded. Too much tension maybe? I did quadruple check everything, turning the motor over by hand multiple times. I also had the VC off for a valve lash after the timing belt install when I checked the belt again, it seemed fine. I've done timing belts before with zero problems, this motor is cursed.

 

It's possible that one of your cam gears, tensioner, water pump gear, or crank gear is just slightly bent; that might cause the belt to shift. Over tensioning might cause the belt to jump a tooth, but I've never seen it shift enough to cause damage.
Have you seen the motor run with the timing cover off? Does the belt appear to shift at all when running?

 

That's really interesting. I didn't really think about something being bent. The water pump is brand new, with about 400 miles on it total with the mileage between the two timing belts, as is the same with the tensioner. The lower crank gear and camshaft gears are old, however. I've never actually watched the timing belt as the car has ran. I've had the valve cover back off after running the latest belt for a bit on the motor, with no visual change in placement on the cam gears, and no change in tension. The guy that I bought the motor from didn't mention anything about timing belt problems at all (doesn't mean he would though...) and the timing belt I took off of the motor before I replaced it the first time appeared perfectly fine. I still have it, actually.

The way that the damage appeared to occur to me was that the belt moved towards the inner cover and became a bit shredded, apparent from the rubber dust remains, then it probably jumped off the teeth from there. The way the car was running, perfectly fine, makes it seem like the the belt didn't jump off the intake cam teeth UNTIL i lifted off the throttle peddle, and then the motor died down probably due to the timing jumping. I'm guessing it jumped timing at that moment because of a change in engine load. The rpm's would've dropped from cruising (roughly 3300-3400) down to idle which is about 700ish for this motor. I'm thinking that is what caused the timing to jump, and not over tension on the belt.

This doesn't answer my question as to why the belt moved back in the first place though, and I'm still open to other suggestions. I'm interested in looking into some of the gears being bent possibly. I'll probably just pull the head and see what needs to be replaced before I start trying to run the motor to solve the timing belt issue.

 

Pictures for reference before I remove the head tomorrow.

Belt slid back on the cam gears, how it was when I pulled the VC.



Belt touching the inner cover, where there was dusty belt shavings from rubbing.



My favorite. Looking at the up marks on the gears you can see that the intake is almost completely 180 out of timing compared to the exhaust cam, assuming the exhaust cam didn't slip as well which it doesn't appear to have done.



The intake cam gear showing the belt came out of the teeth causing it to slip.



I should know the damage tomorrow. Still don't understand what I did wrong to cause this. I'm going to look into the bent gear theory though and see if that tells me anything. What if one of the cams was slightly bent?

 

After you put the belt back on I would have someone crank it a few times while you watch the belt and make sure it isn't wobbling back and forth.
Did you replace the tensioner when you replaced the belt? You shouldn't need to, but I had a buddy that had one go bad and the belt kept jumping teeth.
From the pictue it looks like the belt just wasnt tight enough or came loose somehow...which would imply that the tensioner is bad; there's no way the belt should be able to get lose enough to sit over the teeth like that.
When the belt was sitting over the teeth in your last picture was the belt very taught or did it feel lose?

 

To answer a few of your questions before my next update:
The tensioner was replaced at the time of the timing belt change, as was the water pump. It's possible that the tensioner is faulty but I'm willing to bet it's not the problem. In the last picture, the timing belt was still very tight, as if it had tension still. This leads me to believe that the tensioner is not to blame. As I stated above, I checked the timing belt after the motor ran for a few days and there was still good tension, and everything was still lined up correctly. I've got a really bad update upcoming with pictures which I think may partially explain at least why the timing may of jumped.

 

I'll let the pictures do the talking...













Sorry for the blurry images. The head is obviously junk now, the scarring is way too deep on the journals. The intake side is quite a bit worse then the exhaust side but the exhaust side is scarred bad too. The Caps got it pretty ruff as well. Now I have a junk type R head, and junk type R cams.

I'm guessing the cams were binding up in the journals while the crank was spinning the timing belt. The cams were wanting to stay still so the belt just jumped over the teeth causing it to jump timing. That doesn't explain at all what the hell happened that would cause the damage that was caused. I've only been running the motor for about 150-200 miles since the last timing belt install when there was absolutely no damage even remotely close to this. So all of this damage to the cams and journals happened within the last 200 miles, after the last timing belt install. It's almost as if oil wasn't getting to the cams at the #1 caps. I lubed them up like crazy before I put them in, so they weren't installed dry. I never had any issues with oil pressure. What causes this sort of thing to happen?

Does anyone want to buy a perfectly good type R head complete with cams? There's nothing wrong with it at all, I swear.

 

yep and/or cam caps being scarred will cause proper torque on cam cap bolts to b way to tight and can pop the timing belt. Installing the middle cam cap backwards will starve the head of oil. I have a pic of my ****ed up head in my sig... i think. I ran my **** looking like urs for another 20k miles after first finding it. I went to put some gsr cams and found what u just showed me. I said **** it, put the new gsr cams in, put hardly any torque on the cam caps, installed everything and dailyed it with nitrous (75 shot) for another year and a half before it finally spun a bearing and I blame that on the lucas and 10w40 I put in it...

 

After readin ur post i def think u put the middle cam cap on backwards. If u dont give a **** about the block (it may b too late but I dunno), reinstall the head, and when ur tighting cam cap bolts use a 3/8 ratchet and put ur hand all the way to the end with the socket and turn almost as hard as u can. Thats what I did and ran it for another year and a half

On a stock honda motor iv never seen valve to piston contact although they are interferance motors.

 

Thanks for your reply man. I'm entirely aware of the middle cam cap being on wrong, causing the head to be starved of oil which is exactly what I would've expected to be the cause of this. BUT, before I pulled the cams out, that was one of the things that I checked, as I was trying to go through a check list of things that I may of done wrong. All cam caps were on correctly, facing the correct direction (arrows pointing towards cam gears). It does seem like the right side of the valve trains were starved of oil though. Number one cam cap is the worse, then number two has some slight scarring on it, but the middle cap/journal onward are all fine. So it does appear that right side of the valve train was starved of oil, somehow. I'm kind of stumped. All of the cam caps were torqued properly.

On a lighter note, pistons are fine. It does look like one intake valve touched the piston in the #3 cylinder. However it was just slightly, like enough to disturb some of the carbon build up and not hurt the piston in any way. I have seen some damage before in stock honda motors where valves have been bent due to p2v contact but it looks like I got lucky again...Either way I'm going to get a different head. The damage is too much to ruin another set of cams, or possibly have the same thing happen again while cruising down the road. I'm thinking the cam was binding which is what caused the belt to jump on the gear. I'm going to be in the market for another head...sucks because this head was perfectly fine before this happened and I don't understand what caused it.

I looked for that picture of your scarred head and couldn't find it. Could you post up the link? I'd be interested in seeing it. Also, I like that b17 block you've got up for grabs. I have a db2 with the original b17 that I'm looking to rebuild here shortly. Thanks man.

 

i've seen that happen when the timing belt is too tight.

 

I must of never taken a pic cause I dont c it either and I sold it a while back along with the b17 block. Sorry man but It looked exactly like what ur showing me. In fact after I installed the gsr cams, remeber I said I had to take them back out for some reason, well when I did the gsr cams didnt even have a scratch on them. They didnt get ****ed up until I tightened the cam caps to spec and popped the timing belt, then when I took them out they were all scarred up. I just reinstalled the bolt lightly and kept on riding.

 

You've seen this kind of damage to the head and cams just from over tightening the timing belt? Maybe I did over tighten the belt...I was thinking that that the right side of the head (T-belt side) wasn't getting oil for some reason and that's what caused it to get chewed up; and the timing belt jumping was just an aftermath of that. Maybe I got it backwards though, maybe the belt was too tight which caused the chewing to take place and the belt to jump. I've never heard of this kind of damage due to an over tightened belt though...

That's crazy that you threw it back together with the head like that. I would be too worried about the same thing occurring again. At least they were just gsr cams and nothing too special. Thanks for your input.

 

sorry to revive an old thread but i just rebuilt my b16 and the exact same thing happened to me, cyl 1 cap journals and cams all messed up almost identical to yours, caused cams to bind and t belt to jump on my way to work this morning, what did you do to fix/resolve this issue? able to save the head with the messed up journals? im so lost cuz ive never had oil pressure issues either, also my bolts on top of those cam caps were dry almost like there wasnt enough oil in the head.

 

Wow, I'm going thru the same situation right now.
suck!