Angry at myself

[Neptune]

I need some diagnostic advice from the forum. It happened when I was on my way home from work Thursday night. It was almost midnight and I had some open road ahead of me so I decided to try the so called "Italian tune-up". This is with my '96 Grand Am GT with 3.1 V6 and about 86,000 miles on the clock. I put it in low 2 and started to run the tach up, not paying much attention to the speedometer, just the tach. I had to stop for a traffic light and when green took off. I hit about 5000 to 5500 rpm (red line at 6300) when I heard a pffftt!!! sound come from outside the car. As I approached a traffic light, I slowed to a stop and then my heart dropped. I could hear it, a low sounding knocking sound coming from the engine. I pulled into a parking lot and could really hear it coming from the lower part of the engine. The car won't go into passing gear if you try. It feels like it is losing power.
Must drive easily and give it gas gently to go up hills or it doesn't want to go. Now, I'm no expert but i think I spun a bearing. At this time I can't get another engine put in, the labor alone would be too costly. So, any ideas on how to keep the knocking under control so I can keep driving it for a while longer? I just changed the oil to Rotella 15w40 to help with the noise. Any additives I can try? I'm pretty angry at myself for doing this to a otherwise very good and dependable car. Incidentally, I had about 3300 miles on the oil with 15% MMO in the crankcase to help with cleaning. Quess I don't need to worry about cleanliness now. Bummer!

 

[The Critic]

Is the check engine light on?

 

[Colt45ws]

If it actually spun that easily then it was ready to go anyway. You would have tried to pass somebody a week later and have it let go at the worst possible moment. There is no reason an engine in good mechanical condition cant be wrapped out occasionally. Otherwise, why have the rev limit set so high?
I wouldnt be too hard on yourself.

Any way you can take a video or something and post it on YouTube so we can have a listen?

 

[chad8]

Blame the mmo. you thinned out the oil. Solvents and rpm's don't mix well.

...Just kidding!!

That pos 3.1 has all kinds of known problems. I would find a decent backyard guy to confirm your diagnosis. It might not be as bad as you think.
I have a friend with the famous government motors 3.8 . Very similar motor to yours.. He was sold and paid for everything from a plugged cat , to intake gaskets to a tune up to fix Lower end noise with low power. His regular mechanic said it was a broken ring. Turns out it was a broken valve spring. A low tech back yard guy found and fixed it. Fill that crank case with something like Lucas, motor honey, or stp just to see if it quiets the noise temporarily and increases power. It might not be a bearing.

 

[demarpaint]

I have no idea sitting home what you are hearing, so this is just an example of what happened to me once. I remember years ago a 302 Mustang I had that lost power after a hard run, and was making some odd noises. I came to a stop, and realized that beating on the car caused my muffler to fall apart internally. A new muffler fixed it.

If your exhaust sounds normal, ignore what I posted above.

 

[scurvy]

Originally Posted By: Neptune
I just changed the oil to Rotella 15w40 to help with the noise. Any additives I can try?


Additives won't fix mechanical problems. If you think you spun a bearing, you probably need to dump what's in the sump, remove the pan and start looking.

 

[duaneb9729]

+1 on finding a reasonable mech to really look over the car, dont jump to conclusions because making the wrong choice here, without getting all the facts will cost more than a trusted mech advice.

If I could make a suggestion, if you decide to take your car in, just discribe the noises and the lack of power, dont give out your conclusion, let them tell you whats the matter.

That way your not planting a seed in the mechs mind.

Good luck, and please listen to colt45ws, he is 100% correct in my mind

 

[saberz]

I doubt he spun a bearing. The 3.1 may have faults(mostly gaskets) but spun bearings is not one of them. They are pretty darn reliable.

 

[onion]

From what you describe, I'm guessing you have a valve-train problem. Does the thing run rough in addition to the low power?

If that's the case, then I'd suggest that you quit driving it and pull the valve covers. It MIGHT be a relatively easy fix at this point. But IF you have a damaged rocker or something (not uncommon on these engines) AND you keep driving it- subsequent damage can be severe (like a dropped valve... and you don't want one of those).

 

[tomcat27]

agree - it might be a relatively minor problem that can be fixed for a reasonable cost. if you keep driving it you may make things worse.
actually, I thought the 3.1 was known to lose the back bearing... regardless, perhaps the bad bearing can be replaced.

 

[StevieC]

Originally Posted By: Anies
I doubt he spun a bearing. The 3.1 may have faults(mostly gaskets) but spun bearings is not one of them. They are pretty darn reliable.


+1

Can you post a video or at least a sound file with a couple throttle snaps so we can hear what's going on?

Aside from that STOP driving it until you can get it diagnosed. Simple problems can lead to disasters if not fixed early.

 

[JHZR2]

a knock without "going into passing gear" sounds to me like an AT issue. Given the mounting, both are underhood, right?

 

[Gene K]

The 2.8 had a tendency to break cranks. Is this an issue with the 3.1 as well?

 

[Scott_Tucker]

I really doubt it is a spun bearing. Driving your car like you did with only 86k on it shouldn't have hurt it at all. Bring it to a mechanic and have it properly diagnosed.

 

[IndyIan]

Originally Posted By: Scott_Tucker
I really doubt it is a spun bearing. Driving your car like you did with only 86k on it shouldn't have hurt it at all. Bring it to a mechanic and have it properly diagnosed.

+1 You weren't even at redline, I used to have an 81 Omega with the 2.8L which had a bad habit of shifting back to 1st gear if you floored it to pass at 45-50 mph... It held together.

 

[scurvy]

Personally I don't think it's a spun bearing either, I was suggesting a course of action since the OP did reckon it was one. Proper diagnosis is always the best place to start.

I agree with the suggestion that this may be a transmission issue instead of an engine issue.

 

[saberz]

From the sound of it along with the mileage it could be a Cat issue(sputtering/stuttering.) The 01 Impala I had randomly went from normal cruising to OMG I think my tranny is dead. It wouldn't move at all past 25/30 mph and would choke/sputter. Cat was replaced under warranty(had 72k on her at that point). Car drove like normal afterwards.

 

[jazeo]

Since he mentioned spun bearing, isn't it possible to pull a plug wire one at a time with the engine running to see if the knocking sound decreases when that cylinder isn't firing?? Wouldn't that narrow it down for him!

It's only a question, I know nothing about the type of engine he has...

 

[c3po]

Originally Posted By: Neptune
I put it in low 2 and started to run the tach up, not paying much attention to the speedometer, just the tach. I had to stop for a traffic light and when green took off. I hit about 5000 to 5500 rpm (red line at 6300) when I heard a pffftt!!! sound come from outside the car.


Transmission

Quote:
The car won't go into passing gear if you try. It feels like it is losing power.


Transmission

Quote:

Must drive easily and give it gas gently to go up hills or it doesn't want to go. Now, I'm no expert but i think I spun a bearing


Transmission

I think something happened because you put it in low 2

Aren't the lower gears for going up a hill when there is snow on the roads or something to that affect, I don't think those lower gears are menat to be taken up to 5000 to 5500 rpms. JMO

 

[Colt45ws]

Umm. If you mash it then the trans will end up in a lower gear than cruising gear anyway. What difference does it make?

Yes, you could test the bearing theory by pulling spark plug wires. The only thing is because of the DIS ignition, you will drop two cylinders if you remove one wire. So itll get you down to a pair of cylinders as a possible. I dont know if it will make a difference on a main bearing.
I agree that it might be a valve or something, too.