I have posted about a vibration some where in the car while running parked. I received a lot of helpfull replys. Now I have a miss just driving around town. At 80 it runs fine. My milage is good but the miss and vibration is frazzling!! Just picked the car up from the Chevy dealer after they had it for four (4) days. Paid for a rental car for the four (4) from them. They tell me they cannot find the source of the miss, or the source of the vibration. The motor only has 13,000 miles on it. I bought the car 4 months ago from a little old lady and she had a file of receipts.
The dealer said the balancer looked ok and did not want to change it to see if that was it. Could be a clutch, fly wheel problem. They further said that there was a lot of after market parts that were not GM.
This is my first vette and not (quite) ready to give them up, However I thought about it. Where do you go when a Chevy dealer says "I dunno"
The car is an 89 in great condition with 93,000 miles, new leather interior, etc. I bought it for 9k. Not out a lot of money. Bought an older one because I didn't know if I would like them, but love it.
Considering having a motor built by a builder who has built two other motors for me. They are Fords however. The motors are balanced by him. Really considering it. I would know what I have then.

Just venting, and looking for thoughts.

Russ
:banghead: :banghead:

 

Have you considert a major tune-up , I mean everything like Air Filter, Spark Plugs , Gas Filter, PCV Valve, Rotor, Distributor Cap, Distributor Coil , Spark Plug Wires !!!

Good luck

 

does it miss at idle?
first we need to try and figure out where this miss/vibration is coming from.
only when the car is moving? when you rev in neutral?

give us more info, we'll figure it out for you.

 

Can you see the vibration on the spring loaded pulley that takes up the slack in the accessory belt? The first thing I would try is removing the belt and let it run for a short time and see if it it still there. Dont run it long since the water pump will not be cooling the engine.

After you rule out that possiblity you can pull plug wires one at a time and see if you get a change in idle. If you pull one and dont get a change you found that either the plug wire is bad or the plug or cylinder is the cause.

 

Done it all, plugs, wires, cap, rotor, coil, air filter, fuel filter. All AC Delco. The vibration is there when the car is parked, not a wheel thing!
The dealer checked the injectors and said they are fine.

Russ

 

well, then do what brookman suggested first. run it without the belt. if the miss is still there, check exhaust temps with a heat gun.
is it an auto or m6?
(edit) i see its a m6. could be a clutch problem too. while its parked,if you engage the clutch, does the miss /vibration change in any way?



[Modified by neverendingproject, 3:12 AM 12/12/2003]

 

Clutch in or out, no change!

 

Did you check the harmonic balancer?
:smash:

 

I don't see where you posted that you did as suggested....pull the belt to see if the vibration disappears. At least that eliminates the accessories and possibly the the bolts that secure them. It might be a good idea ,however , to go over those bolts on all the accessories just to be sure.

 

Who did the tune up? Years ago I had a new set of wires that I installed & where it routed behind the left head it was touching the retainer for the battery cable & rubbed a hole... bingo instant miss. Happened on a trip to the coast & when I opened the hood after dark, engine running you could see the spark leaking quite clearly. Replaced that wire & all was well.

 

The balancer was checked by dealer. Said it appeared good, done the night check with no light on, looks ok. I put the wires, plugs, cap, rotor, coil on myself. Dealer pulled plugs, and the distributor, everything ok there. I have been working alot and have not had a chance to pull the belt and run the car. Sound like a good idea though.
The dealer has run out of ideas, and said they can not help me with out just replacing stuff to find the problem and they do not want to do that. They think the problem may be internal.
I retire in 28 days and have pretty much decided to pull the motor and have one built to factory specs and balanced w/clutch assembly. I will know what I have. I want to be able to take off and go and have peace of mind!!! :steering:

 

Was the miss and vibration the reason you did the tune-up? If not, then something you changed has caused the problem. I bought new plugs for a tune up one time and after installing them the car just didn't run right. The idle was not smooth and under a load it missed pretty badly. After some head scratching I decided to buy another set of plugs because that was all I had changed or done to the car. Turned out the parts store sold me the wrong plugs the first time. Put in the new correct plugs and problem was solved. Car ran great. I know the dealer said they checked everything but you might double check to make sure that you were given the correct plugs. Check each one to make sure. I worked in a parts store for awhile and sometimes a part would be put into the wrong bin.

If the problem existed before you did the tune-up, then I would think that something was not done correctly during the rebuild of the engine. There are other things that come to mind concerning the new parts you installed but without knowing if the problem existed before you did the work it would not be helpfull to list them at this time.


[Modified by George Dickel, 9:17 PM 12/13/2003]

 

One thing I have learned since I started building engines over 20 years ago, you can ask 20 different mechanics and you'll get 20 different answers.

My suggestion (take it for what it's worth) is to determine if it's electrical, fuel, or drivetrain. Assuming the dealer has put your car on a scope, they should have been able to determine if it's electrical. I doubt a fuel problem would cause the type of vibration you are describing. It could be as simple as a valve too tight.

I would think you either have an internal balancing problem (however, if it just came about, unless something broke, I doubt it would just start out of nowhere)

That leaves in the drivetrain. It could be something as simple as motor mounts (I purchased a brand new S10 from the dealer, complained for 2 years about a factory vibration and didn't find out until I was putting an LT-1 in it that the whole problem was a broken motor mount). Unless you have a broken flywheel or something bad in a torque converter, it eliminates the rest of the drivetrain because you said that you had the vibration while in park.

Just a few suggestions but like I said, my answer is one in 20, just trying to offer some more assistance.

Mark