Grrr, car problems AGAIN! How bad are these symptoms?

[stonecold3169]

Alright, so about a week back I had posted a thread about a surging of power when going uphill, and someone corectly diagnosed ignition miss. They were right, there was a bad wire which was cauign a cylinder to not fire. So that was fixed, and they car ran and idled better then ever before, for about a week. This is a '95 cutlass supreme 3.4L.

After driving about 10 miles a few days back, I got a significant power loss, something akin to my timing belt slipping, it was very severe. There was no noise when this happened, and it didn't knock or anything of the sort. I pulled over, popped the hood, checked it out, checked all fluid, etc, and could see nothing generally wrong with it. Started it up, starts fine, idles perfect, but when I put it in gear it knocks badly. Keep in mind, that even if it's in gear but standing still it knocks badly.

Now, if I had a downed cylinder, wouldn't my idle be knocking too? and if my timing belt were messed up, wouldn't it have a hard time starting or idling correctly? Any ideas what this could be? Someone suggested to me that it could be a bad oxygen sensor, but I'm not so sure... opinions?

 

[compudog]

I am not 100% sure on your car, but I know that when you go from "curb-idle" to anything else, the timing is advanced, usually by a vacuum device on or near the distibutor, this would be what I would check (vacuum advance). If your car has a computerized system with fuel injection it's likely to be that. I don't think IMO that there is any serious damage yet, but timing issues can lead to bent cranks etc if they are allowed to continue.

 

[Eli]

What do you mean by "knocking"?

Putting the car in gear wouldn't cause your engine to start pinging.

 

[stonecold3169]

It's an actual knocking, as though there is a cylinder down, as in a banging. I don't think it's an actual problem with the cylinder though, because it didn;t start doing that until I restarted, which makes me think it's a timing problem or something.

 

[Ladies Man]

when i had my timing advanced it wouldn't knock till i put a load on it...
try a higher octane gas and get it fixed before you need a new engine...

 

Alright, so about a week back I had posted a thread about a surging of power when going uphill, and someone corectly diagnosed ignition miss.

That was me.

Started it up, starts fine, idles perfect, but when I put it in gear it knocks badly. Keep in mind, that even if it's in gear but standing still it knocks badly.

Too many variables to diagnose over a BBS, I need more info.

Is the knocking a loud metallic sound ?

Does it sound like preignition ? (Spark knock)

Does it sound more like a ticking ?

Check your oil for metal particles, warm up the engine in park, shut off engine and pull the dipstick, wipe the dipstick with a clean white cloth, look very carefully at the cloth for tiny metal particles in the sunlight. (It will appear as sparkles).

Check the tightness of the engine mounts, bellhousing bolts and torque converter bolts.

 

[Bleep]

When you first start the engine and it starts the knocking press the gas pedal down very slowly to rev the engine and see if it stops knocking, if it does it may very well be a connecting rod (not good) if the knocking keeps up let up on the gas and listen for knocking if it stops on the way down it may be a wrist pin or piston slap. Any sort of metallic knock in a engine almost always spells BIG and expensive problems.

Bleep

 

I guess stonecold3169 doesn't want my advice anymore.

 

[agnitrate]

Originally posted by: Roger
I guess stonecold3169 doesn't want my advice anymore.

You must have fixed the problem again.

2 for 2!

-silver

 

[stonecold3169]

hehe, sorry, I didn't check my emails yesterday and didn't see that there were more replies to the topic.

So far it looks like compudog was the closest. looks like I have a bad coil, for the exact reasons he listed (no distributor here). While not the cheapest thing to replac, it's much much better then what I was fearing could be wrong. Thank you everyone, especially compudog and Roger for helping me out this time and also last time... who woulda thought AT could have such knowledged people!

 

[CraigRT]

damn those 3.4 engines... great when running, but not always running

 

[stonecold3169]

Originally posted by: Yield
damn those 3.4 engines... great when running, but not always running

I'll tell ya though... the car is loaded, has every feature I could ever want (power everything, power sunroof, cruise, AC, HUD, power attenna, nice stock stereo), is decent on gas for a V6 (get 22mpg city driving, 29 highway), and looks decent and is peppy enough for a college guy like myself to drive... nice stuff for an oldsmobile

These are the first engine problems I've had, I've babied this car, it's just showing some wear and tear (135,000 miles on it, I put the last 65,000 on it myself). The thing I REALLY hate on it are these @$$@$# calipers. They seize like there's no tommorow, which means changing pads (and sometimes calipers if you can't knock the pins out). I've tried loaded calipers, but no good there either... gets expensive, esspecially when you factor in rotor wear. All in all, for the features I got, buying it 2 years ago for $3,000 was one of the better purchases I would consider having made.

 

[compudog]

Glad to have helped. I don't mind changing brakes on later model GM products, has become almost a pit stop. My '99 Malibu get a brake job this coming weekend. Hey, for an hour or so worth of my time and a $35.00 parts investment I will do my own brakes and not pay someone $90/hr labor.