Pretty bad Vibrations

[GTA_V6_Mustang]

Ok well on a cold start I get a pretty bad vibration felt in the car. Above 1,200 RPM it seems to go away cruising it goes away too, even if i am below 1,200 RPM. One of my friends seems to think it looks like the engine is missing below 1,200 RPM. Spark plugs are new, cap is clean, and rotor is clean. When I look at the crank its pretty stable I dont see the harmonic balancer doing anything but spinning (No wobble). I pulled the pcv valve and it was pretty bad looked like it had been in there since 94 the p/n sure wasnt fram or purolator i guess it might have been motorcraft. But yea i replaced the valve and grommet and the car definetly feels better but the vibration is still pretty abnormal. What do you guys think? Could it be the clutch causing this problem? Maybe its damaged because when I do like take off normally and at a low RPM it shakes a bit but if I raise the rpm to 1,500 or above it engages smoothly. Or could it be a bad coil? I Have no idea whats going on. thanks for any help guys.

 

[Bosko5.0]

its most likely the harmonic balancer on the front of the crank. check to see if there is rubber coming out from the between the balancer metals.

mine had the same problem

just cuz you dont see the balancer wobbling doesnot mean it did not rotate from the right position.

also check vaccum it should be around 18-20 stock.

 

[mo_dingo]

try a cylinder balance test and see if any of them appear to not be firing.
Scott

 

[GTA_V6_Mustang]

Cylinder balance test?

 

[Adam95GT]

harmonic ballancer +1... mine just went had the same problem... it will get worse... lol...

Check behind the bottom crank pully and ballancer... and see if you can feel rubber... if so... its bad...

its about $60 for a pioneer products one from Advance auto... go pick it up and rent the puller and installer its free with a $100 deposit to rent... took me about 1 hour total for the pull/install... remover coolant tank... and fan assembly... put the car in 5th then loosen the bolt on the ballancer its self on the bottom of the crank... 15/16'' IIRC... then the 4 bolts the crank pully 1/2 or 13mm i think.... use a 3/8'' extension to relive the tensioner on the belt and remove that... then fully remove the pully infront of the ballancer... then remove the bolt AND the washer from the harmonic balancer then use the puller to remove it from the crank shaft from underneith... you should befine on ramps that what i used... you will also need a phillips screw driver 2 remove the sheild for your rad and fan.... along with an 8mm socket for the 2 bolts on your fan assembly and the one holding the coolant tank in place... there will also be 2 more bolts on a braket holding the coolant tank inplace.... they will be under the sheild..

hope that helps..

 

[GTA_V6_Mustang]

Ok well I just got the harmonic balancer from Advance. Luckily since I am friends with everyone there they let me use one of their discounts so it came out to 50with some change ($50.78) But well tomorrow I am changing it after work. So ill let you guys know what happens. Hopefully the shaking goes away and yes behind the balancer i feel like a rubber lip that came out. You know like a swollen lip after a boxing match .