Need help troubleshooting a string of problems...

[jimstolz76]

I can't believe there's an Aveo forum and I never found it before today!

I've got a 2005 Aveo LT that I've had since new. About 2 months ago it broke down, leaving us stranded for the first time, and I've had a string of problems ever since. I'll list this out in chronological order, because the timing has GOT to have something to do with it...

Thermostat housing snapped in half while the wife was driving to work. Managed to get a new (metal) one and replaced it in the parking lot. Coolant had blown ALL over the engine.

A week later the wife calls on her way to work again and said the car is making a really bad screeching sound. Oh great. She makes it to work, and a friend and I drive up to take a look at the car (she works the night shift...) We go to start the car and it won't catch. We had to try about 4 times to get it started. Once started it idled rough, engine light and HOLD light came on and were blinking. (engine code ended up being Random Cylinder Misfire) We stopped the engine, took a look at top of the spark plugs and it looked like the valve cover gasket had been leaking and the coolant blowing around and made oil get down into the spark plug wells. We pulled them all out, cleaned everything up as much as we could, put it back together and it started and ran just fine. Then I backed out of the parking space and heard the noise. The freaking brakes were shot! LOL what a coincidence...

The next day I replaced the brakes and valve cover gasket. I also did a more thorough cleanup of the spark plug boots and wells. Car was running great... with one caveat...

Ever since the thermostat housing broke, the car has been hard to start. Some days it's worse than others, but what happens is this. You hit the starter and the car barely turns over, then sounds like it's going to die. Sometimes it does and you have to retry. BUT - once the car has been running for around 1 minute, something "clicks" (not literally) and it instantly starts running smoothly. Once the engine has warmed up at all, when you turn the car off and restart it, it does NOT give you any trouble at all...starts right up. It should also be noted that there is some valve tapping that seems to coincide with the rough idle.

The only things I've done so far are to replace the spark plugs (didn't change anything) then later changed the wires (didn't change anything).

Now it's getting worse. The difficulty of startup is still random from day to day, but now it's idling rougher than usual all the time. I'm going to be replacing the timing belt in about a week and would really like some insight into what else I should be doing at the same time.

To me it seems like an electrical or sensor issue. What else would make it suddenly "click" and run normally?

Would GREATLY appreciate any advice! And if anyone wants a non-rambling, "abridged" version of this post, just let me know...

[thehunterooo]

sorry about the stat, sound slike you got everyhing in shape, it is the battery im guessing, either time for a new one or it may need some water, did it smoke/does it smoke at all

anyways, welcome

[jimstolz76]

The battery? Really? Actually it does seem to be getting some corrosion on the positive terminal for some reason. It's not weak when it's trying to start, it's just something isn't "catching" in the engine... you think the battery may be related to this?

And yes, I do occasionally get some white smoke at startup. I think it's only happened 2 or 3 times in the past couple months. It's so infrequent I forgot about it until you mentioned it.

Thanks for the quick reply!

[thehunterooo]

np, any smoke is coolant burning off, but its just getting cleaned out, if it was something like the alt then the battery wouldnt be charging, and you wouldnt be able to turn the car on at all, i know im missing something though lol

it only gives you issues on cold starts?

[jimstolz76]

I AM still losing some coolant somewhere. I've had to add it twice since I replaced the thermostat housing. Haven't had a chance to search for the leak. I have a feeling the housing isn't seated exactly right - I had a TON of issues getting the 2 pieces of the housing plus the thermostat to all stay in the right position while putting it on (plus I was burning my hands and working in a parking lot....LOL)

It does only give us trouble on a cold start. Cold being a relative term. The other day I started the car when it was 95 degrees outside and I had to try 2 or 3 times to get it to stay running. Once it's started for a minute it runs fine.

Problem is now the car is idling rough all the time. So it's a progressive problem and I have no idea where to look. No engine codes anymore.

OH, but when the car REALLY struggles to start, the HOLD light will flash. Not sure if that means anything. Once the car runs normally for a while the HOLD light will go back off.

Unfortunately I don't have the money to throw at this problem. I imagine it would be a nightmare for a mechanic to troubleshoot, since he would only have about 1 minute each day to see what is happening... once the car has warmed up, it stops! LOL

[thehunterooo]

a cold start meaning that the engine has not warmed up, the engine tempature on a GM car can reach about 180 degrees, it takes an aveo about 5-6 minutes to warm up for me in the summer in florida, I have a list of things that you can do

Disconnect the battery for 30 mins or so and let the ecu reset

Check the battery over and make sure its all good

Look at the radiator and the fan, make sure they are working good

Replace the spark plugs if you have not already, make sure the GAP is right, and even look at the wires

Like you said, the housing might not be sealed, that will leak, the engine may even run warmer, or the housing is restricting the coolant, if the engine gets too hot it will burn up coolant, hence the lost of it in the first place I think that may be a possible problem lol, brainstorming is fun

Other than that I dont know, i still want to say its the battery, take it to the autopart store and let them look at it, thats what my gut is saying, i also think that the engine is being scamed of coolant somewhere too, had a similar problem 2 weeks ago with my friends saturn, the fan relay thingy was not working, and the fan was not working, he thought it was leaking coolant too but it was using it up to keep the engine from overheating

[jimstolz76]

Well the battery HAS been disconnected since all this happened... I tried to clean the brake pedal switch and apparently it got stuck too far in, because the next time I went to the car the battery was dead... Then I replaced the switch and did the same damn thing.

So the battery has been dead for more than 30 minutes, so that should have cleared the ECU (I'm guessing).

Any chance it's the IAT or MAP sensor? It REALLY feels like an electrical problem. I'm thinking something got doused in hot coolant and isn't working correctly. Unfortunately I don't have the money to throw at this - otherwise I would change each sensor one at a time and see what happens.

The rough idle may be something unrelated to the startup issue. I remember the car idling a little rough from time to time at startup, but nowhere near this bad (it was barely noticeable) and only happened maybe once every 50+ startups...really random.

[jimstolz76]

update -

Changed the timing belt yesterday. After 83,000 miles it actually looked exactly as good as the brand new one, just a bit dirty. We were shocked! It looked incredibly good, especially for a car with notorious timing belt issues. But the big thing we found was the timing idler pulley had a crack all the way through one side (outside edge down to the center shaft). Once we took it off we felt that the bearings inside were completely shot. You could wobble the bolt all over the place.

Changed the timing tensioner too, which looked fine. Changed the water pump which looked like it had been weeping. I'm thinking that may explain the slow loss of coolant that just started happening. Changed the serpentine belt which was covered with cracks and totally ready to be changed.

Everything went really well. The hardest part was getting the water pump twisted in the right spot, but we had pulled the motor mount so we just used channel locks. We also drained and refilled all the coolant while we were at it.

The car now runs great, but there are 2 things:

1. The starting issue appears to be cleared up! I've only been able to do a cold start twice since doing the work, but it starts right up. I hadn't realized it, but it had been bucking when I was trying to start it before. Even with the throttle body and air intake full of cleaner it didn't buck at all and just caught after a couple cranks. The second time I started it was barely one revolution (I may be exaggerating) and it caught. I wasn't expecting this to clear up, but now that it's not doing it, I can see how it did kinda feel like the timing was jacked up when it wasn't starting. The rough idle/running seems to be gone as well.

2. I've had a noise which we figure is noisy lifters, but now it's worse. There used sometimes be a loud valve tapping for about a minute after startup, then it would stop in an instant. As the car ran in would kinda come and go and change how it sounded. My friend who helped me said that type of sound is usually related to hydraulic lifters. Now the initial tapping is a good bit louder and keeps going for a good few minutes before stopping. It also makes more noises and changes sounds more often. We both think it's a bit odd since we didn't do anything with the oil or oil level. Hopefully it's just a minor nuisance and isn't indicative of a different problem

All in all it went VERY well and we are both really happy with how it turned out. I'm extremely happy that the starting issue may be gone, but I'm reserving myself until I get a few more cold starts out of it.

Time to take a break, then its on to a forum search on "noisy lifters."