Newbie with Aveo in need of timing belt/head help

[DRG2003]

Hey all,

New here but been lurking for a few weeks. I guess I'll start by explaining how I came across my 05 Chevy Aveo. My friend decided to drive cross country from MA to AZ. I warned her to make sure everything was up to speed on her car maintenance before she left. I specifically mentioned the timing belt after looking up the interval it should be changed and reading the horror stories. She decided to chance it and broke down in WV. The shop there quoted her $2000 for repairs so she was going to just leave it and let them have it. (!) When I started saying how crazy that was, she said if I got it here I could have it. So... $725 later it arrived in VT.

Once I dove into it found that the timing belt didn't actually break... the plastic idler pulley shattered and chunks melted/wedged themselves at the bottom against the crankshaft pulley. Even though I knew it was an interference engine and had most likely jumped time I decided to chance it and just install a full timing belt kit and see if it cranked. Did that last night and nothing.

So looks like my next step is to pull the head and check for valve/piston damage. Going to work on it this week a little at a time after work and into the weekend. Any tips for pulling the head? Can I easily tell if the head needs to be machined or just the valves replaced? And if just replacing valves is this hard to do myself?

Thanks for bearing with me on the long post. I'm used to working on VWs so this car seems nice and simple compared.

-Dan

[avguy]

You said you tried to crank and got nothing - I'm assuming it did crank (turned over), but didn't fire and start up. Is that correct? If so, did you at least do a compression test, if only to get a baseline of where the engine is currently at?
I (fortunately) haven't needed to do head/valve work on mine, but from what I've read it doesn't sound like anything out of the ordinary for that type of job.
Now here's one other thing to consider. When these interference engines go bang and bend valves, that means those valves have made some major contact with the pistons. So my question on this has always been, what does that contact do to the bottom half of the engine? I'm thinking about not just the obvious damage to the top of the pistons that can be seen. but also everything else, right down to the crank. We get people posting about replacing valves or installing a new head, but generally that's the last time they post. I don't have any real warm feeling that fixing the head issues will result in an engine that will give many more trouble-free miles. Do most of these head/valve repair jobs go South a couple thousand miles down the road due to bad bearings? IDK - I'm obviously not a pro who does lots of these jobs, so it's all speculation on my part. It would be great to have a mechanic post that they have done many of these jobs resulting from interference valve bends, and none came back later with lower engine problems. Until that happens, JMHO but I would skip the head repair and drop in a new engine instead.

[Daox]

I agree with Avguy. I got mine like you got yours, except the previous owner tried to start doing the work himself, then he gave up. A salvage yard engine can be only slightly more expensive, and its pretty easy to drop in. With any luck you'll find one with less miles than the original engine.

[classic67]

Id use this as a swap prodject. Since the engine is gone do the cobalt ss swap find out what you need and sell what you dont. This idea is based on if you have a current runnig car to drive while its under the knife.

[classic67]

Wait hold up if your used to working on vw then you should be the first to swap a vr6 into an aveo
.................It would be epic

[DRG2003]

Haven't done a compression test... I figured at this point that I would be ripping it out for one reason or another. Don't have very many salvage yards around here so finding a used motor might be tricky. They're all around $1000 on eBay. After doing the whole timing belt kit and it not working (which I knew in the back of my mind anyways) I needed a few days away from it. Might finish pulling the head tonight. The car is in great condition overall but there are some bolts (mainly exhaust manifold) that are quite rusted on and holding me up. Will update once it's pulled.

[DRG2003]

Got the head pulled! All 8 exhaust valves are bent with a little bit of the head dinged up around where they seat. Is this a big deal? Wondering if I should play it safe and send it out to be checked out/valves replaced or attempt to do it myself. Intake valves looked ok but didn't make a point yet of rotating them out to see if they're damaged. Pistons look ok too... just a slight grazing where the valves made contact. My mechanic said they should be fine as long as I make sure there aren't any burs that could cause hot spots.

[dmcnelly]

All said, that actually doesn't look too terribly bad. If you've done valve work before, you should be alright, if not, having a shop recondition a head all around for you should be fairly cheap considering what you paid for the car, especially.

[DRG2003]

Alright finally an update! Money has been tight lately so been ordering stuff when I can. Got all the exhaust valves out today with this sweet spring compressor I got from Amazon.com



Here they are next to a new one:



Upon getting them out I found I have some broken valve guides too. Like an idiot I didn't order them yet hoping the old ones would be ok. Getting those ordered today since no one around here stocks them. So much for getting the car back together this weekend. Any tips for getting the old ones out/pressing the new ones in?

[DRG2003]

Well after 9 1/2 hours this past Sunday, she's all back together and runs great! Smooth quiet idle and drives nice. Couldn't find where one wire connector goes (pic at bottom) but in the meantime it doesn't seem to be affecting much.

After new valve guides, valve seals, and of course valves putting the valve keepers back in. I was surprised these went back in a lot easier than they came out.




Head back on and new timing belt kit installed:




All together! (Except for the air box... screws were all rusted in so we had to cut them out... back in now)



The one mystery wire that I can't find a place for. If I remember right it's on the same section of harness that goes to the alternator. Not very long and I can't find anywhere it could reach to. It's pretty clean so I'm sure it was plugged in before. Anyone have any ideas or pics? Driving me nuts.