ndanl

hi,

I own a 1991 corvette (L98), 66k on it, with automatic transmision, I recently managed to make the car run again, rebuild the transmision also changed the tc, changed plugs/wires, filters, oil, some sensors, everythings fine, no dtc errors, but the engine vibrates, I can fell the vibration in the steering wheel and when I acceletare the vibrations gets stronger, its like my mom washing machine, any advice please ?

thanks,
Dan

BerniesVette

Too many possibilities to make a guess. Since it is felt in the steering I would check air pressure in the tires, wheel balance, tie rod ends, ball joints, idler arm and shocks; all of which could cause your problem. This should get you started.
Bernie

ndanl

the engine vibrates with the car sitting, so we can exclude the tires/wheels and all about car steering ...

engle1147

Take off the belt and run the engine for a few seconds (~30 seconds max) to ensure that the vibration is from the engine and not the accessories that are connected to it.

How long did the car set without running?
Fuel system may be full of old/bad gas?

Muffin

Vibrate is a big word. Can you narrow it down a bit. Are we talking about a rotational vibration or something like a miss fire?

What Pete said. He always faster than I am.

stevie1dr

I'd also check to see if your getting spark to all eight cylinders. Another possibility might be the harmonic balancer.

ndanl

the car was sitting for more than 6 years before at the previous owner, now the car has new gas filter, new air filter, new fuel pump, new injectors, new spark plugs/wires, new oil/filter, managed to rebuild the transmision in romania, new torque converter, new belt, new belt tensioner, almost anything that could be changed "outsitde" the engine

yes it is a rotatig vibration that feels like growing with the engine rpm

ok, first I will remove the belt and run the engine without, will come back with the results

thanks guys

gerardvg

Hi i had a similar fault that the engine would run rough and shake on acceleration....
Test 1 run engine for 20 seconds and check exhaust temp close to heads
iff all are the same temp... i had no 2 cylinder cool and was the injector connector .... did that after replacing ecm,maf,distributor,burn off, tps sensor and exhaust sensor.
test 2 check maf,tps sensor connections and check voltage at tps
Test 3 check spark plugs they could be fowled up

Good luck

Lemme

Even I have a rotational vibration in my 84 whilst stationary or driving that gets really bad around 3000 rpm. Up to that point the car revs/drives perfectly though the vibration is there at a lesser amplitude.

It is frustrating because I want to test it out at WOT and I suspect something will break if I run it over 3000 rpm for an extended period.

I will do some tests in parallel to see whether we can both solve our problem.

94vettelover2

Was the problem there before you did all that work?

tblt44

Harmonic balancer
I know 2 people that it went bad on there mustang,the one said it felt like the whole car was vibrating when it went

LD85

take the serpentine belt off and see if the accessories are causing the problem, just a simple way to eliminate any part outside of the engine.

Lemme

Is this as simple and easy as it sounds?

LD85

sure, just support the rear of the engine so it does not drop

Muffin

You don't need to do that. Remove the inspection cover, unbolt the TC , three bolts , slide the TC toward the rear. You should get something like 1/2-3/4 space between the TC and flex plate. The engine-trans mounting bolts are not touched.

LD85

evidently it is different than a manual tranny, the engine would dangle by the mounts if you don't support the engine

Mark_Milner

Duh?


The torque converter bolts with three bolts to a flex plate.

Unbolt it and slide it back into the transmission about an inch. You do this by removing the lower access cover and the transmission remains bolted to the engine.


On a manual, there is no torque converter. There is a pressure plate, that ONLY connects to the flywheel. It clamps between it and the flywheel a disk that rides on a splined shaft from the transmission.

To get to this on most manual transmission cars, you HAVE to unbolt the bellhousing from the engine to get into the pressure plate. Very few have a two piece bellhousing you can remove an access panel on.

LD85

I never would have figured this out, thanks!

ndanl

ok, belt and tc are off, engine still vibrates like it is off balance, maybe the harmonic balancer is damaged, will order a new one hope to get it next month ...

do I need to order anything else besides the harmonic balancer like gaskets or something like that ?

could be a problem with the distribution timing, I dont know maybe a few degrees more or less, but I never touch it ?

thanks,
Dan

tblt44

check here for the harmonic balancer.
I get many parts from there,good prices

here you go saved you some time

http://www.rockauto.com/catalog/raframecatalog.php