ok This vibration will not go away. I had anothe post but i cant find it...

ANyways this is a 93 S-10 with 2.8 5 speed

This thing has a very very bad vibration, I replaced the ballancer, I checked the flywheel and it is the correct one for this engine, and I have no clue what else it could be.

If the crankshaft was bent wouldnt the oil pressure drop?

At idle the whole truck shakes as if it was fireing on 4 cylinders, and at around 3-4K rpms it will make your hand hurt from vibration if you hold the shifter.

 

Are you sure it's a 93 with a 2.8? I think they all had 4.3's at that point, and I think the 4.3's had a balance shaft in them. I might be wrong though.

 

cranks just dont bend out of the blue.. it takes ALOT to bend one.. for example, i threw two rods and siezed my motor at 6300rpm.. and that barely tweaked my crank.. but it was enough to have to trash it..


maybe your motor is firing on 4 cylinders.. pull each plug, one at a time.. while it is connected to your plug wire, touch the plug to the chassis(ground) and have someone crank it over to see if you get a spark.. do that for each one to rule out spark..

thats all i can think of

 

Thinking about it, from what 2_point8_boy said, I think they discontinued the 2.8 after 89? Or at least before 93 I think. I'd go to a Chevy dealership and ask them. Parts depaertment would know.

If so, if a 2.8 was in the 93 (means the former owner swapped the 4.3 for the 2.8.....who knows where the 2.8 camr from then???), maybe you have the wrong flywheel and what not on it. Maybe the 2.8 was from a pre 88 or whatever year that was balanced externally or something. So, you could have a neturally balanced (is that what its called?) flywheel on an externally balanced engine....or...um..yeah I think you get the point lol.

Simplified, maybe you have a really old 2.8 (that was put into the 93) and although the listing for a newer 2.8 (the internally balanced 2.8s) calls for a neutural flywheel, maybe it needs a different type of flywheel because the 2.8 is actually an old 2.8

Of course, if you went to a parts store and they actually have a listing for a 1993 2.8 (How did you check if you have the right flywheel?), that kinda blows my whole theory lol



Anyway, just my two cents.
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Just realized you said in your original opaost that you have a 93 with a 2.8 as well.

But it could be correct too. Maybe there was an older 2.8 swapped into the newer 93.

 

yes for the S-10 they made the 2.8 in 93 it was the last year.
The engine is internally ballanced (it has a one peice rear main) and the flywheel has no holes drilled or weights on it . And I ran the numbers to make sure and it is the correct flywheel for internaly ballanced later modle 2.8's

I also checked the spark with my timming light, they are all firing, and the compresion is good. I had a mechanic look at it also and said it is deffinatly not missing, its just got a vibration.???

PLEASE ANYONE!!! LOL I cant let this thing sit. Thanks for everyone trying to help I am just getting clueless because I have done everything except replace the flywheel.

I would just let my uncle drive it (its his truck) but I dont want the bearing to fall out of it or get beat all up.

 

Hmmm.....ok....I know Im no professional but I'm stumped (Actually, I just wanted to use that smiley lol )

Interesting to know that they used the 2.8 till 93 though. Out of curiosity, are the 93 S-10s MPFI or TBI? I know all the S-10s i saw were TBI but i havent seen anything aside from the 80s models. I had ONE bad injector and although it ran well, the car vibrated like crazy!

oh, just a thought...stuck EGR? Happened to me and caused quite a bit of vibrations too.

 

i have the EGR unhooked, and almost all the vacume lines plugged off. I dont have a black off plate for the EGR how can i tell if its stuck?
as for the injector, this might be possible but the truck was running fine with these injectors with the last motor?

and yes this is a TBI 2.8

 

So you have a new balancer, and the flywheels part number is matching what it should have?

Make sure all the bolts are flywheel and clutch. Make sure thats all assembled correct.

any knocking?

vibrate in gear as well as neutral?

what about motor mounts? One of my actual BRACKETS broke on mine.


(use to work on 3 different 93 s10/s15 with 2.8 tbi's, but this even has me stumped)

 

I was wondering what led up to the vibration. It sounds like an engine swap or something took place. Knowing what took place prior to the vibration should help out.

One item that toss's some is the firing order and #1 cylinder. 1 2 3 4 5 6, with #1 being passenger side front.

RBob.

 

just throwing this out ,have you checked the pilot bearing in the end of the crank shaft ,had one crack ,vibrated like hell hope this helps jimmy

 

I reaplced the pilot bearing with a new one, and the firing order is set correctly.
I did do an engine swap, The motor locked up in my uncles truck, and he so I swaped in another motor for him from the same year S-10.
The motor mounts seem OK, there is some slight cracking but the motor is not jumping or anything.

The flywheel numbers match the engine both are interaly ballanced peices.
There is no knocking

and yes it vibrates in gear as well as out

 

It may be that the crank is bent. Doesn't seem to be much left. IIRC a while back a guy from Germany had a V6 3rd gen that vibrated. He found that the crank was bent.

Can you check the runout on the flywheel? Or, at idle observe the flywheel and see if it wobbles a little?

RBob.

 

yea I looked at the flywheel at idle, I personly coulnt notice any SHAKE or wobble to it.

 

Hmm, if it has a mechanical fan pull that off and see if it makes a difference.

I found the thread with the bent crank vibration:

https://www.thirdgen.org/forums/v6/1...ke-my-car.html

The guys name is bernd5179, from Austria, not Germany

RBob.

 

forgot about the mechanical fan, good thought rbob!

 

pulled the fan, its still there!!!
This is so aggrivating, i really dont wanna put in another engine... looks like thats my only option.