hello all you wise and helpful people out there. (and i mean that in the most hopeful way.) my daughter recently bought a '04 gts spyder, and it is a beautiful car! unfortunately, she fell in love with it before i had a chance to see it or drive it. when i did drive it, i heard an ominous thumping sound out of the passenger side floor board sounding just like a single loose big end bearing. i replaced all of them, but the noise persists. sounds like a bearing, and tracks with rpm, but when i listen directly to the motor, i hear nothing but the usual clicks and whirrs. this is not a quiet car as the engine sounds like it's bolted solidly to the frame. if anyone has a clue, i could use one. thanks

 

Sorry, kinda hard to diagnose a noise over the computer. Not sure what you mean by a "single loose big end bearing", but I would inspect the CV joints, tie rods, etc. Anything related to the front end. Seeing how you say it follows RPM, I would lean more towards CV joints.

 

it does it in park and while driving and follows engine rpm.

 

So what do you mean by the big loose end bearing and what did you replace?

 

not big loose end bearing. loose big end bearing. that's the bottom, or big end of the connecting rods.

 

I'm just trying to understand what you have done so bear with me. You have torn the engine down and replaced the connecting rod end bearings and the noise is still there. Hopefully you didn't pay some one to misdiagnose the issue. So we can rule out rod bearings. OK, how about the accessories (PS pump, AC pump, etc) Timihng belt, idler pulleys, water pump...all driven by the engine. Those been checked? How many miles on the car?

 

thanks for the reply, and nope, i was able to misdiagnose it all by myself. however, while poking around under the car with the engine running, i did find the source of the noise. the fuel pump! yes i do feel stupid, but it mimmicked a loose rod perfectly. pulses from the pump are travelling down the line and everywhere there's a bracket it transfers to the body. is this the fuel pump wearing out?