What the hell just happened!?
 

So i was taking my alero for it's weekly drive around the block when i decided i wanted to take it on a large trip to just get everything going after sitting for a couple months. So took it on a 100 mile round trip through NH and Maine. When i got back to NH i was going to exit the highway and enter a traffic circle, and it was congested to i WOT'ed off the exit ramp to get into traffic, when i did that it revved to 6,200 RPM and then made a LOUD bang like the engine had just blown itself a new ahoe... It them proceeded to misfire like it HAD blown, and would die when i took my foot off the gas, (i also SWEAR i heard metal hit the road) so i was just trying to limp it home but i saw no smoke, oil stains or heating up.... all of a sudden it started running perfectly like nothing ever happened, no heating up, no leaks, no running rough, nothing seems to be missing from the engine, what the hell happened? Someone want to enlighten me? the SES was already on and i know it started blinking for a minute. i just drove it to work to further see if it HAD blown the engine, and it's fine, it just stinks because of a bad Upstream O2 sensor. The tranny shifts smooth as silk, and it has tons of power (i WOT'ed again getting onto the highway on my way to work) Other then that no loss of oil, no loss of coolant and it's running right at 196*F.... what the hell did i break?

Maybe the cat was clogged from sitting and when you hammered it it blew out any debris and it chugged and bogged while it blew out... ??
I had this happen with an old Toyota from sitting for 6 months...

Sounds like it just had a little cough and needed to get some junk out of it's system.... I'd say, if it runs fine, then I wouldn't really worry about it.

coughed up a lugie?

It's a new cat, and i swear i heard shit hit the road! I'm going to pull the codes tomorrow and see what cylinder was missing and check around it. It sounded like the engine blew apart! i just drove it home, WOT'ed in the same spot and it sure as hell screamed, but no explosion this time, sounded like any old healthy 3400 under load revving high. I seriously thought the engine was done for... i just don't get what happened.

exhaust backfire due to too much fuel?

Friend says the engine detonated and it is most likely severely damaged internally? If that's so I'm gonna just scrap this alero and buy another one...

I vote for bad backfire, thanks to a mislead from the defect O2. After that the PCM readjusted itself.

probably wanna check all the codes, repair whats broken and then take the batterie off for a while to reset the PCM / BCM
then drive it normally.

I once hat a backfire in my Camaro, sounded like the car was ripped apart. My first and only misfire :eek:

If you bent the valve it would probably be making noise right?

I just went outside and started it cold, the only thing i heard was the noisy lifters... I guess this is another life the engine's used.... two sets of HG's... three LIM changes, many, many MANY coolant hose ruptures and blowoffs, overheated several times.... and it still has full compression, doesn't leak/burn anything and has tons of power (car always was a complete factory freak) this is a true testament of how strong a 3400's internals really are... oh and i put almost 130K on it just myself. she's nearing 250k now... -sniff- i'll snag codes tomorrow. let you guys know what's up!

EDIT: Just used my work account to order all the parts i needed... Plugs, wires, upstream/downstream O2's and a LOT of TB cleaner and some seafoam... let's see how this shapes up.

thats 402 thousand kilometers -- holy shit thats about 2.23 times what I got on my '99
*knock on wood*

I believe it. After all that sand in my oil bullcrap, it still doesn't burn oil... Just made the lifters loud as hell... No rough running or anything.


..... Then again my engine could take a crap at Any moment

Make sure you didn't blow the welds off your intake manifold. :lol:

flashing ses light: catalyst damaging missfire. just an fyi

i swear to god my eco did that same thing! once just cruising down the highway, another time during a wot 15m after seafoaming and that time there was even smoke. still going good today

For one thing you should probably not be doing the who WOT thing. It's like asking for trouble, especially on an engine that has lots of miles on it.

unless there is damage to the motor, low oil, or extremely poor maintenance then WOT doesn't hurt a thing...He didn't say he held it at WOT which could ultimately cause problems...I WOT my truck which has 303,000 on the motor and it doesn't hurt anything, in fact I tend to have more issues develop if I try to baby it then if I just run it...I can't speak for his area, but I have driven in plenty of places where if you are scared of WOT then you will never get anywhere...the fact is though all cars are mechanical and no matter how well you take care of mechanical objects, or how much you baby them, they all wear out at some point...I could see where you could see a problem with doing WOT after it had happened, however everything seemed fine, and sometimes the best way to diagnose a problem is to try and recreate circumstances

Now me and the mad scientist have to rip apart the block and replace the piston rings you just fried Nate! :lol: :lol: :lol:

This ^^^ My dad's 07 1500 has 70k on it; and when you get on it, it just doesn't feel right. Now my alero @130k and my girls 90 calais @105k both get rode hard at times. The calais will just stove up and wont have any power till it gets rode hard.

In Detroit they have some of the shortest on ramps i ever seen. It's like on ramp going down to interstate (steep hill). Then you have 50' of level ground to move into the flow of traffic that's going 80mpg.

Side note, i did have a weird problem when i first got my 01 GA in 02. 2.4. On wot WOT at would start blowing white smoke like the head gasket went. Dealer said the pcm needed an update.

And she sounds great! I will admit i kinda expected it to blow someday, but i guess it's fine... weird!


Nah, 3400's are bulletproof, look at all the times mine's had coolant soak the crankcase, and the bottom end is still tight!

Oh no! that can happen? These were milzy's LIM/UIM.... :cry:
I'm aware, i used to have a lot of issues with this car eating spark plugs, so that light's done the whole raw fuel dumping in the past.
So it banged, and it sounded like metal bits from the engine hit the road? I've NEVER had this happen to me, why i thought some part fell off....

Exactly! My engine is otherwise perfect, oil is clean, no low fluids, new rad, new HG's 25K ago, same with LIMG... so there's really nothing that can happen.... except it blowing up again because of the 02...
Oh god why! Wanna do a rebuild in the Hotel parking lot i stayed at? :usa:

We have STUPIDLY short ramps here, and cars that don't have a v6 or more usually have to go into the breakdown lane to get up to speed! every time i get on the highway i need to WOT whatever i'm driving... :lol: