Deal on a 94 V6

[Dave M]

Yes... In cold weather climates like where Tracy is, and here in NEw England. Between October and May, the gasoline is oxygenated.

I don't believe it's oxygenated for driveability concerns. I thought it was pollution worries that caused them to oxygenate gas? I don't really know for sure, but I wouldn't think weather would have that much affect.

As for TraceZ's gas, it may have gotten condensation in it from the difference in temp/humidity of when it was filled versus when it was used. Filled in humid, hot July and then allowed to cool to -5 could have very well put water in the tank. I would drain the tank and get some gas line dryer and fresh gas before replacing parts.

[TraceZ]

Last night we did the following:

replaced the spark plugs
replaced the spark plug wires
replaced the fuel filter
replaced the PCV valve
Seafoamed the engine
added Duralube to the engine oil
added Duralube to the transmission fluid
added Duralube to the power steering fluid
added a bottle of HEET to the gas tank

It runs well now, and fairly drives well also.

The only issues it has now is a vibration in the engine. It feels like something is out of balance? I'm changing the belt on it, So I'll test run it beltless and see if the vibration goes away. It's also throwing a code for EGR. We'll have to replace that too. There is also a bit of gear whine coming from the differential. I'm thinking we should change the fluid and add some Duralube to it. My Dad says that made the rearend in his RV silent, where it used to whine.

[Joe 1320]

It runs well now, and fairly drives well also.

The only issues it has now is a vibration in the engine. It feels like something is out of balance? .

Check the engine and trans mounts. Most engines that run well but produce vibration are usually traced to this. If those are fine, check the crank damper. Thoise have been known to seperate and be out of balance.

[TraceZ]

Check the engine and trans mounts. Most engines that run well but produce vibration are usually traced to this. If those are fine, check the crank damper. Thoise have been known to seperate and be out of balance.

Thanks Joe. I'll check those things out!

I know how to check transmission mounts, but how do I go about checking the motor mounts?

[fastTa]

Thanks Joe. I'll check those things out!

I know how to check transmission mounts, but how do I go about checking the motor mounts?

Look for signs of the rubber drying out or cracking in between the mount. Heet will help remove condensation but won't touch the gas if it has begun to gum up. Drain that gas tank boy!

[TraceZ]

I removed the TB and cleaned it all up. I soaked it in Simple Green and attacked it with a tooth brush. After all the grime was gone I wire-wheeled it to make it look pretty and reassembled the sensors onto it. I also rebuilt the EGR valve. It is held on with 2 bolts and once removed from the car it comes apart pretty easily. It has 3 magnetic plungers in it, each controling a different sized valve. One was seized up hard in the open position. I took it all apart, cleaned it all up really good with my wire wheel and reassembled it. No more SES light and it runs really nice now.

I didnt get a chance to look at the motor mounts yet.

At the end of the night I went to remove the key from the ignition and it wouldnt come out. It appears the park-lock interface cable has broken. That's one more thing I'll have to fix now. I wasnt planning on more stuff falling apart as I am trying to fix it up.

The throttle response is great now with the TB all cleaned up. The car drives perfectly. The vibration is about 50% gone and the gas tank is down to 3/4. We added an entire can of Gumout to the gas last night to help clean up the fuel system. Could bad gas possibly be causing the vibration? It feels like something is out of balance more than a fuel related issue. It is not a misfire, or at least it doesnt feel at all like one. It is more of a resonating vibration, but like I said it is 50% gone now that we did the TB and EGR.

[TraceZ]

tonight we changed the rearend fluid in an attempt to quiet it down. It helped a little, but not what we hoped for. There was almost no fluid in it, but there are no apparent leaks either.

Regarding the vibration::
I have not had a chance yet to look at the engine or transmission mounts.
at idle in gear it is terrible
at idle in park is is barely noticable
at 1000 RPM it goes away completely
at all other RPMS the engine feels great.

I dont think the trans mount has any problems because we let it shift at redline a couple times tonight and there wasnt any noise under the tunnel.

I also replaced the windshield wipers, painted and tightened the antenna mast and painted the wiper arms. There were some scuffs on the mirrors so I used plastic polish on those and now they look new.

I saw some posts on a V6 forum with exactly my vibration issue. I joined the forum, i'm now to be verified so I can post and ask what the solution ended up being.

[TraceZ]

Well, I've decided to listen to some advice for a change and ordered two new motor mounts. I spoke with a friend of mine that manages the local Chevy service center and he said he could just about guarantee it was motor mounts. He said that over time they dry out and get hard. Once they are hard they no longer isolate engine vibration and it will rattle the teeth out of your skull. He said he has seen may vehicles come in mis-diagnosed with misfires when the actual problem was bad motor mounts.

So they are on order. Installing them will be fun!

[SteveH95Formula]

Hmmm I have a '91 Sunbird with a 3.1 L V-6 and am getting just a hint of vibration. I just changed wires, plugs and all three coils as well as a lot of sensors. (Oxygen, IAT, TPS, MAP, etc.) I'll check my motor mounts too. Its front wheel drive but it shouldn't matter.

[TraceZ]

Update

I worked on the car some more tonight and managed to get 1 motor mount replaced (drivers side). The vibration is better than half gone! I'm sure replacing the passenger side mount will completely eliminate it. Whew.

We replaced the gasket under the EGR riser and the exhaust leak is gone now too. This car is really starting to take shape. It should drive like new very soon.

Looking at the old mount, it does not appear dried out, but more deformed. The rubber in it is pushed one direction and bulged out a bit.

[Joe 1320]

Update

I worked on the car some more tonight and managed to get 1 motor mount replaced (drivers side). The vibration is better than half gone! I'm sure replacing the passenger side mount will completely eliminate it. Whew.

We replaced the gasket under the EGR riser and the exhaust leak is gone now too. This car is really starting to take shape. It should drive like new very soon.

Looking at the old mount, it does not appear dried out, but more deformed. The rubber in it is pushed one direction and bulged out a bit.

Glad that it's working out.

[TraceZ]

Glad that it's working out.

Me too, man. I was worried about that vibration. I just finished test driving it after replacing the last mount and the vibration is now completely gone. I finally felt comfortable enough with the car to let Tami test drive it and she thinks it is great.

Something under the car is still rattling a little. I was hoping that would go away with the vibration, but it still rattles a little even though the vibration is gone. I'll have to get under there and see what it is.

Also, the brakes feel like crap. It sat in a wet environment long enough to corrode the front rotors pretty bad and they never smoothed back out again. I thionk I'll toss on some new pads and rotors in front and bleed the lines.

total costs so far:
$500 - car
$250 - parts

[Joe 1320]

total costs so far:
$500 - car
$250 - parts

Nice going. You and I should open an f-body refurb business on the side.

[TraceZ]

Nice going. You and I should open an f-body refurb business on the side.

I was actually thinking about that last night. If only I had a heated pole barn and a place to store parts cars. There is nothing on these cars I can't make like new.

Last night I removed the passenger seat, stripped the cloth off it and washed it in the wash machine. It came out looking new. While the seat was out I shampooed the carpet on that side, and the carpet looks new now too. I also removed the center console and completely rebuilt / cleaned it. It also looks new. All that is left is the drvers seat, carpet and dash. This interior is seriously going to look *showroom* new when I am done!!

Wanna move up to Wisconsin and go into business together? We dont ever get hurricanes here, ya know!

[fastTa]

Me too, man. I was worried about that vibration. I just finished test driving it after replacing the last mount and the vibration is now completely gone. I finally felt comfortable enough with the car to let Tami test drive it and she thinks it is great.

Something under the car is still rattling a little. I was hoping that would go away with the vibration, but it still rattles a little even though the vibration is gone. I'll have to get under there and see what it is.

Also, the brakes feel like crap. It sat in a wet environment long enough to corrode the front rotors pretty bad and they never smoothed back out again. I thionk I'll toss on some new pads and rotors in front and bleed the lines.

total costs so far:
$500 - car
$250 - parts

Good to hear the vibration is gone! Those clamshells can distort after a while. Check the heat shields for the vibration. I had a vibration that I had a hard time finding, and it ended up being a loose heatshield. Also check the converter inspection/dust cover.