04 Engine surging and rough idle

So this past January 2015 I heard a funny noise coming from the timing belt housing, so I had a mechanic check it out. Turned out to be a bearing in the water pump, so I had him replace the pump and, since he was in there, the timing belt. Fast forward to a couple weeks ago while driving I hear a loud tearing noise and the car stops.

Had the Aveo towed to the mechanic who opened it up and it the belt was partially chewed up but didn't break. It turns out the mechanic had dropped a bolt in the timing belt housing and it finally worked it's way into the crankshaft sprocket and tore up the teeth. The local mechanic replaced the belt and crankshaft sprocket, however the engine now runs rough during idle and surges. Although he tried his best, the mechanic could not figure out why the engines surges during idle now.

Anyone have any thoughts as to what is causing this issue? The engine idled fine before this.

I had the same mechanic replace the belt 5 years and when I went to pick it up, it had a similar issue, however, he was able to correct it. This time, unfortunately, he was unable to do so.

Maybe check the compression on each cylinder. I guess it could be possible you nicked a valve.

Or it's off by a notch. Or a sensor or vacuum line wasn't plugged back in properly after putting it all back together.

Sounds like the timing may have jumped off by a tooth or so. I would hope that this mechanic is fixing the Aveo on his dime?

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Originally Posted by slayerized6

Sounds like the timing may have jumped off by a tooth or so. I would hope that this mechanic is fixing the Aveo on his dime?

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The new belt and crankshaft sprocket he replaced for free but then, after having it for 2 weeks, he gave up. Told me to take it home and see if the issue corrects itself. He seemed convinced that this issue is not a result of his mistake. Of course that's more than likely BS but what can you do?

I've got the car at a different shop to see if they can find the issue. If it is related to the timing belt/crankshaft sprocket, I plan on having this new shop right up a detailed report. I'll take that back to the old mechanic and ask for some reimbursement. If he's not willing to help, I'll probably look at a small claims suit. I really hope it doesn't come to that though.

timing belt is off a tooth on one sprocket somewhere. mine did the same and it was off by one on the exh cam.

Car is at the second shop again. Low compression on cylinder #1. Suspected valve damage.

Took the estimate and diagnosis back to the original mechanic who promptly changed his story. Instead of a bolt that he definitely dropped in there it is now a metal piece that broke off of some magical place inside the timing belt housing.

After much arguing he agreed to pay for half. However he later changed his mind and said to have the other shop find out exactly what the issue was and, if it's his fault, he'll cover the whole thing.

I'm concerned that the shops are in cohorts now (it's a small town) and that no matter what the issue, it will definitely not be related to the original mechanic's mistake.

I'll update after I have to pay out of pocket the $1300 it's going to take to fix his mistake.

I'd suspect it was an installation mistake that caused this mess. But if he wants to claim a defective part, that's ok - he can go after the part outfit he used. However, the bottom line is you should not be paying a cent for this repair. Make it clear that you will take him to court for full reimbursment if he makes you pay anything to get your vehicle back. And keep going back until it's running as well as before all of this happened.

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Originally Posted by avguy

I'd suspect it was an installation mistake that caused this mess. But if he wants to claim a defective part, that's ok - he can go after the part outfit he used. However, the bottom line is you should not be paying a cent for this repair. Make it clear that you will take him to court for full reimbursment if he makes you pay anything to get your vehicle back. And keep going back until it's running as well as before all of this happened.

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Vehicle is at a completely different shop now. The original mechanic lacks the capacity or resources to pull the head off and replace/repair the valves if needed.

If this is an issue that I'll end up in court over, I'll still have to pay out the money to the other shop just to retrieve my car.

The original mechanic is staunch in his stance that a bolt he dropped into the housing that lodged itself in between the crankshaft sprocket and the engine block, shredding the sprocket and belt and causing the engine to seize up, has anything to with this issue even though the car ran fine before any of this happening.

I feel for the guy because he's super nice and just a working guy. This $1300 bill will hurt him and his family but it's just not my fault. I did everything right.

Not trying to kick this mechanic when he's down, but IMO he shouldn't be doing timing belts unless he is capable and willing to also do corrective repairs that are caused by his mistakes. Do enough timing belts and a few jobs will go South - $hit happens. Paying retail prices to another shop to fix his mistakes doesn't seem like a professional operation to me.

Next, I just cannot understand this story about "dropping a bolt into the housing". I've done 3 of these jobs, and the only thing I'd consider possible to drop in is one of the timing cover bolts. But he would have to know that there was a bolt short on the cover, and that would be a huge red flag for any competent mechanic. Sending a repair job out the door plus or minus a bolt is a hack job.

But regardless of that story being true or not, he's admitted to making a major mistake, and that is enough to close the case right there. Even if here was no admission on his part, he would still be on the hook, unless he can show that you spend your time redlining your Aveo around the track (and even then a timing belt job should last more than a few months).

I understand the "family" and "nice guy" thing, but it's either him or you. If you decide to bargain to some middle ground, that of course is your call. In that case you could consider it a non-deductible charitable contribution.

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Originally Posted by avguy

But he would have to know that there was a bolt short on the cover, and that would be a huge red flag for any competent mechanic. Sending a repair job out the door plus or minus a bolt is a hack job.

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Funny you should mention this. When my car seized up, and after I had it towed to my house, I peeled the timing belt cover back to see if it had snapped. While fooling around there I stuck my finger into the bolt holes and sure enough one of them was missing.

I brought this up to him this morning and he also noted that there was a bolt missing from the housing but claimed there was no way he would have dropped that particular bolt. He was entrenched in his lie at this point.

He's going to lie to get out of this repair and the costs associated with it. I have no proof other than his word against mine since he tossed all the old parts before I thought to ask them from him. If I decide to take this to court, I'll have a tough case to prove.

Closure!

Valves were damaged in one of the cylinders and the second shop was able to repair the problem. The original mechanic that caused all these problems actually did the right thing and paid for the entire repair. There was no denying that the valve damage was from the timing issues caused by the bolt he dropped that destroyed the sprocket and belt.

I was out of a vehicle for 1 solid month and I'm out some towing fees but I'm just glad this is all over.

I am SO happy that mess is resolved. I'm glad the original mechanic manned up and did the right thing. Maybe he will think long and hard before doing another major repair or service like that. We honestly don't know how many other timing belts he has replaced, this could've been an honest mistake...


Happy driving!

:vtec:

There is a plastic idler wheel in the timing belt loop - the wheel recently shattered on our 2004 Aveo causing the timing belt to lose tension and crashing every valve! I would have the mechanic replace every pulley, tensioner and wheel in timing loop!

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Originally Posted by tringoldsby

There is a plastic idler wheel in the timing belt loop - the wheel recently shattered on our 2004 Aveo causing the timing belt to lose tension and crashing every valve! I would have the mechanic replace every pulley, tensioner and wheel in timing loop!

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When you replace the belt, you replace everything. The idler, belt, and water pump.

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Originally Posted by aveostein

When you replace the belt, you replace everything. The idler, belt, and water pump.

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Yes - definitely replace *everything*. In the case of our idler, the bearing was perfect (even after it shattered) so it hadn't given any concern during the previous timing belt change (40,000 KM = 25,000 miles before). I had never anticipated the actual plastic wheel would disintegrate!

If there is a weak point to the early Aveos, it is the timing assembly. The Aveo has the shortest timing belt change interval of any car I've ever seen and they aren't kidding!

So, change anything and everything in the vicinity of the belt that could possibly cause a belt failure. I really question the engineer's decision to make it an interference engine. Sure, you get a couple of extra HP and perhaps a trifle better fuel economy - but the cost of a broken belt outweighs any possible gains.

I should mention, there is a tensioner and an idler, IIRC.

This is info about rough idle and surging-bought my 2004 Aveo sedan last year. Had timing belt changed at dealer who took a week because they had to wait for a water pump gasket. Car was idling rough and surging after repair. Found 2 spark plug leads switched. Fixed that. Still rough idle, low power. Finally replaced spark plug leads with new ones. Car ran like it was new after that.