vibration up to 1800 rpm

**JayTA98** · 02-03-2011, 02:37 PM

I have this vibration that I feel when the car is stopped in park gear. If i slowly accelerate I feel the vibration in front of the vehicle. It feels like when you drive a car with an unbalanced wheel. Is not too strong but I can feel it. The vibration stops around 1800 rpms. I spoke with a friend and he told me is possible that I have issues with the harmonic balancer and/or the
converter(A4). He told me that engine mounts could cause that too. I already order the mounts because im doing the oil pan gasket change and I need to drop the K member.

Is this true about the harmonic balancer and/or converter? How can i check to see which one is the one causing issues? Thanks.

**cammed goat** · 02-03-2011, 06:22 PM

With the engine running, watch the crank pulley and the belt to see if there is any wobbling. Also, are you running the factory crank pulley? I dunno about the converter, nor if there is an inspection plate under the bellhousing that is removable. If there is a plate and it's removable, raise the car while the engine is running and remove the plate to see if the torque converter is wobbling. As far as the mounts go, do the brake-torque method. With the parking brake set and your left foot on the brake, give short burts of throttle with your right foot. Make sure you have the hood open and look between the dash and open hood from inside to see if the motor rocks excessively. Keep us posted.

**Cutlass** · 02-04-2011, 02:31 AM

There are some ideas in this thread for your problem
http://www.ls1.com/forums/showthread.php?t=151208

**JayTA98** · 02-04-2011, 02:59 AM

Thanks I'll keep an eye on updates. I will change the motor mounts 1st and see if it takes care of the problem.

I looked at the harmonic balancer, if i look at the center were the bolts are i can see it wabble but when I look at the out outside of the pulley itself it don't wabble. So i guess the harmonic balancer is fine.

**jsmith564`** · 02-05-2011, 04:11 PM

i'm here to tell you this bugs the shit out of me. i've been working on mine off and on for a while.

i thought it was head gaskets, misfire, transmission, somthing in the engine, but never thought of the mounts. but i am most positive it's my mounts.

i done alot of tests that have ruled out a bad engine or transmission.

you're problem sounds much like my problem. i'm getting mounts tomarrow but wont be able to install them till weather permits.

**JayTA98** · 02-05-2011, 06:31 PM

I just got my mounts from summit. I order the prothane 7-512B motor mounts. I will install them sometime next week with my oil pan gasket. I hope this takes care of my vibration issue too.