Timing Belt Broke - what to do?
 

My timing belt broke yesterday on my 2004 Elantra while I was going 65mph. No noise, car just shut off. I have 152k mile on the car. I tried several things today and want to post my results to see what advice i can get.



Today I replaced the timing belt, following a YouTube video. Never done it before, but i lined the camshaft/crankshaft marks up like the video said to do. In the video the guy was just replacing a belt, but mine broke..so i ended up having to separately turn the top and bottom gear to get the marks lined up, then I put the timing belt on. I think i did it right. The car started up after that but sounded horrible and shut off on its own. I then tested the compression of each cylinder. These are the readings I got: 155, 140, 150, and 0. So then as another test, I removed the fuel injector plug to the cylinder that read 0 compression, and started the car up again. it ran better, but was still really rough and sounded bad and felt like it was going to cut off.



I'm looking for advice on what to do next. I have no idea how to inspect the valves or open the head and whatnot. I did see that I can get a used cylinder head on ebay for about $300 after shipping. Is this something I should look into? Or could there be more damage beyond just the cylinder head? Or based off my description would it be better to try and repair what i've got?



One thing to note - I figured i might have valve damage and what not so I didnt fully replace everything I took off when i was putting the new timing belt on. I left the alternator, water pump, power steering, and AC pulleys disconnected. I figured running the car for 10 seconds wouldnt hurt anything. Does anyone know if this could affect my results in any way? I'm pretty sure i have some damage given that I have 0 compression on one of the cylinders...but just want to make sure leaving all that stuff disconnected wouldnt cause issues or skewed results. I know I shouldnt run the car for long w/o the water pump running, but i just wanted to see if it would even start with the new timing belt on.



What should my next steps be? I'd really like to keep the car, but dont want to spend a fortune on it.

Having the auxiliaries disconnected will not affect the running.

Your pistons will most likely be damaged also as that's what hit the valves. Cheapest option to source a second hand engine. Or if you want to add power etc strip down and do a full rebuild head porting, pistons valves etc.

Talking about adding power is useless advice. Also, the pistons and valves can hit and not damage the pistons; only bending the valves.



Check the timing again, you can be slightly off, the car will start, but run like crap. If you do have bent valves, its not the end of the world. You can remove the head have it rebuilt or replace it. You did a timing belt job so you seem mechanically incline enough to remove a head. EBay is cool but If you have a local junkyard you can get a head for half the price and no wait if you're willing to pull it yourself.

Having 0psi in a cylinder is bad news and pretty much guarenteed valve/piston failure



I wouldn't be surprised if you damaged a piston or 2 aswell as bent some valves



Gonna have pull the head off to see the extent of the damage and go from there. Hopefully you got lucky and just bent a couple valves.

To the response that my timing might be slightly off: I'm pretty sure it is on. I have the cam and crank gears lined up exactly like I saw to do it on several videos and websites. Which is, for the top one look through the little hole and have the red mark centered in the hole when looking straight on. For the bottom, line up the white paint on the gear with the marker on the engine block. As seen here: http://www.elantraxd.com/forums/show...ng-belt-change

Is there any other way besides using those 2 guides to know if the timing is off?



What is the % chance you would say that I have damaged pistons? I'm thinking about taking the head off and taking it to a local machine shop, they said it would be maybe $200-$500 depending on the extent and how many valves need replaced. But I dont know what I'm looking at to know if I have piston damage. Should it be obvious to me, or would a pro need to make that call?

Either get a new head and hope that the pistons are fine or get a new engine. I've been there...twice...



I suggest a junkyard engine.

I've seen valves bent so slightly that you had to look close to see which were damaged and which were not, with zero visible piston damage. I've seen valves bent so bad they hammered and dented the piston crown with the EDGE of the valve. I've seen valves BREAK and destroy the combustion chamber and score the cylinder before putting a hole in the piston and heading on down to the sump. You have to pull the head to see which is the case with your engine. Depending on how reluctant you are to open the top end, it may be worth it to get a junkyard engine and just slap the whole thing in there and trust the warranty you got from the scrap yard.



If you are lucky, you need to replace one $20 valve and install $100 worth of gaskets and coolant, plus an oil change. If not . . . well, I'd say to just pull the head and see what you've got first.

Search for the thread I started on this exact same issue about a year ago. My timing belt blew while driving. I didn't realize it so while I was being towed I tried popping the clutch to start the engine a couple times even (probably causing more damage). When I tore it apart it was just one dead cylinder (0 psi compression) with a couple bent valves. There was a tiny knick in the one piston that had bent valves. I just sanded it down smooth and replaced the entire head with a junkyard head. I've been good for probably 10k+ miles now (knock on wood).



If I were you I'd just pull the head to see the extent of the damage. It's not too hard, only takes a few hours to pull everything apart for the layman. If it's just a minor blemish, I say just replace the head or have it rebuilt with new valves and sound down the blemish smooth again. Should only be a few hundred dollars in parts max.

So good news...I think. I got the head off tonight. Here are some pictures of the piston and the valves, for the cylinder where I had 0 compression. May be a little hard to see, but theres 2 little dings on the piston, and on the valves i didnt see any dings but on the edge of the metal frame next to where the valve comes out, there is a little ding. Not sure how bad that is...will take it to a machine shop tomorrow and see what they say. But I'm hoping for the best. Seems like it could have been a lot worse.



Speaking of the head, should I take the cams off or leave them on when i take to the machine shop? Again, I'm a newbie, so i dont want to be the one taking them off unless I know its easy to get them back on right without any special tools or without risking messing anything up. I've taken a lot of risk us to this point since I'm new to this, but figured its an old car, if i screw up an old dead car, i'm not losing much! But i'd absolutely love to revive it!

You have to have the cam out to work on the valve train. If you are taking it to a machine shop, call and ask what they want. They may say to bring it in whole and they'll be happy to charge you more to break it down for you . . . but then YOU aren't the one breaking camshafts! ;)

Took the head in this morning. The estimated work including a $78 head gasket kit is $443, not including $15 per valve that needs replaced. Apparently he said because this head uses shims on the valves, there is a lot of labor involved in getting them all re-adjusted. Cant remember the specifics but he's charging $160 labor for that, whereas some cylinder heads on other cars dont require that. Estimate attached.

FYI a low mileage used engine cost me $305.

Cost me $325 for a long block with 69k and I didn't pull it.

Wow, maybe I should have waited. Theres a local pick your part place nearby that sells cylinder heads for $40 if you take it off yourself.

i got it all back together, and it runs awesome! Thanks everyone for the help. One question though - about the timing belt not staying in the middle of the camshaft pulley... when i put the timing belt on and turned the crankshaft 2 rotations (making sure it was timed right still), the belt where it goes around the camshaft pulley slid to the back of the pulley and the edge of the belt is hanging off maybe 1mm or so. I gradually pushed and pushed the belt back to the center of the pulley with my hands. I rotated the crankshaft again and the same thing happened, so it will just not stay centered. I looked down and the idler, tensioner, and crankshaft pulley, and they all look ok - as in the belt was centered fairly well on those. Should I be concerned? Is there a chance i didnt put something on right? I dont think it is going to come off, as either the tensioner or idler (cant remember which) has a lip on the back that it looks like it cant go past. But still i want to be sure. I've spent a LOT of work in the last 1.5 weeks for it to go bad at this point. Thanks everyone!

When it's assembled that shouldn't be an issue.

The only thing I can think of is a little metal plate that goes IIRC behind the crank pulley, that would space the belt out another ~1/2mm or so when assembled. Does the belt walk off the sprocket when the engine is running or just when turned by hand?



Good job so far, by the way.

I did put that metal plate back on, but that was a good thought! Well, I'm assuming it would walk to the edge of the sprocket when the engine is running, since it did it twice when turning by hand, but I dont know for 100% sure, since the second time it happened when turning by hand I left it there. Are you thinking there would be a difference when turning by hand vs the engine turning it?



So far I've driven 300 miles on it, so far so good. So cross my fingers I guess.

There is a lip on the back of the sprocket and the plate between the pulley and sprocket keeps the timing belt in place, at least on the 1.6l.

Have you checked it again recently?



Sometimes when doing a timing belt, the crank sprocket will slide out on the crankshaft a little, until you bolt the pulley onto it.



So if you were spinning the motor over by hand without the crank pulley bolted on holding the sprocket in place it might "walk out" a little bit.



Pop the upper timing cover off and see where it's riding now that it's back together

^ THAT was a very good answer. It's only a few bolts to pull the top timing cover and have a quick peek. The sprocket on the 1.8s and 2.0s I've seen through the mid-2000s had no lips on either edge of the camshaft (top) timing sprocket to prevent walking off.

Another Hyundai back on the road from us boys at HA.org. Congrats!

I did crank the engine up with the cover off to test everything out before I put the cover back on, and the belt stayed where it was hanging off a little and didnt re-center after running for a few minutes. So the belt walked in, towards the head, not out towards the side of the car. So if anything it seems the bottom crankshaft sprocket would be too far in for whatever reason. That or the camshaft sprocket be too far out for whatever reason. Neither of which makes any sense to me, because I remember when putting it together that it only made sense for anything to be installed one way since there were grooves on the sprockets and a tooth that went in that groove. Someone else asked me if i installed the tensioner correctly. I think so? Seems only one way for that to work too, since its just a bolt that holds it on.