gofasterdammit

Well ive been chasing a vibration in my car for sometime. I thought it was a driveline issue for a while but was wrong. Ive finally found out that around 1200 to 1800 rpms there is a pulsing vibration in my motor. I pulled my transmission and put a different torque converter in thinking it was a converter vibration but it wasnt. In park i can rev the motor and feel a shiver through the car. the more the rpm's the worse the vibration. So bad that while driving the car I thought I had a bad driveshaft. The car will actually shake so bad that i dont drive over 70 on the hiway because i think something is going to break.
Tonight I had the torque converter disconnected and took the belts of and ran the car. What i thought was a rasp noise from my exhaust is actually a noise in my motor. Its not a knock but more of a grinding noise. I checked my harmonic balancer and It looked good as did my flexplate.
Is it a rod bearing or maybe a piston pin? The car did have piston knock when it was cold but goes away once the engine is warm. I also havent heard it for a bit. Maybe a bad thrust bearing on the crank?
I would appreciate any ideas or thoughts what to check. Im going to probably pull the motor out soon. This sucks!!!!

msydow

i would think something in the valvetrain. you can check your thrust bearing by checking end play on the crank. maybe get a good video of it?

JaYZeig

iTrader: (11)

how are your rubber engine mounts? id take a look at them and s if theyre
not ripped/torn, or have excessive movement.

if it were an internal engine noise i would think you'd have a knocking

gofasterdammit

I have had polymounts in the car for about 9 months now and i think they made the vibration worse but it was already there. I did put a screwdriver to the oil pan and the noise is gnarly. Hard to explain but definetly the source of the vibration.

gofasterdammit

Like lifters or trunions maybe?

gofasterdammit

well I took the valvecovers off and removed my rockers and pushrods. The rockers seem good other than there is a little play in the bearings on the trunions. I rolled the pushrods on a surface plate and they were all good. So i put everything back together and drained my oil and nothing to be seen.
So again it seems I have to go deeper. Can a Partially pumped up lifter cause a shiver? Wouldnt there be some signs of metal if the lifter is tapping? I did find a Post about the oil pump o-ring causing aeration in the oil but I dont know if that would cause my noise. Has anyone had a bad timing chain that causes noise? The car only has 110k miles on it and the motor is stock inside.
Any help would be appreciated!!!

kossuth

iTrader: (12)

Reinstall your valvetrain and check the lash on your rockers/pushrods. If you have a collapsed lifter it would be very apparent. Being there is no metal on the drain plug I'm almost thinking it's something not internal. Did you check your coil packs/plugs/plug wires to ensure it's not something associated with that part of the motor. On occasion these coil packs do go bad. Rule them out first. Also, you might have a jacked up fuel injector not feeding a cylinder enough. Being you have no metal and the inside is stock It sounds to me like it's not internal.

A screwdriver test really doesn't tell you much (never did me anyways) because the aluminum block transmits so much noise through it anyways it's hard to distingush what's normal and what's wrong without it being very super apparent (at least for me anyways).

gofasterdammit

Thank You for the info. I never thought about injectors. Your right though, it doesent sound internal. I will check them out and get back.

Ellesone

simple question but what about tire balance

gofasterdammit

I had started thinking all my vibration was is tires and driveshaft issues. at this point ive checked everything and even had my transmission out of the car and fired it up and it was still there. crazy huh? thank you for the thought though.

mdevegas

I had a problem very similar to this, only maybe with a little less of the noise you're talking about. Turned out it was a misfire caused by a wire that had got torn on the header install. I'd check all the coil packs and ignition parts, and rule those out.