90 Bonneville crank damper

I'm pretty sure that's what's causing the ghastly racket when the car is started; once it's warm, it'll still rattle, but not as loudly.

The question: How to loosen the damper bolt?

I've seen this question before, and didn't pay much attention. Search engines don't help much.

If I could get in there with my impact driver, it would be over with very quickly. Unfortunately, there's a bit of frame / unibody in the way.

Any suggestions?

RB

Reply to
Robert Barr
Loading thread data ...

lefty loosy, righty tighty?

Reply to
DA .

It's a regular practice on various and sundry transversly mounted FWD engines to remove an engine mount or two, to gain access to the crank pulley bolt with an impact wrench ("gun"). GW

Robert Barr wrote:

Reply to
Geoff Welsh

I don't recall ever having to drop the engine or subframe down to access the crank bolt. Should be staring you right in the face after you remove the plastic splash shield. If by chance your vehicle is different then all the rest that I've ever seen, then you can always loosen the right side subframe bolts and let the subframe down just a bit.

Ian

Reply to
shiden_Kai

You need a lot of torque to remove the crank damnper, but be careful---the crank sensor is behind it and is easily damaged.

Reply to
Mark Keeling

You are correct. After that, all I needed was a good impact driver.

Turns out the damper is OK, so there's a really nasty undiagnosed rattle that's bugging me to death.

Strangely, the rattle doesn't increase in frequency with engine r.p.m. It really acts like something hitting its resonant frequency. Source (location) is hard to narrow down.

Reply to
Robert Barr

I've seen the damper seem ok before when they weren't. Are there any cracks in the rubber on the damper, or will the pulley spin separate of the rubber?

Reply to
Mark Keeling

Appearance was OK -- I cleaned it up to examine it. Looked fine. No marks where the spokes would have contacted the hub. On the car, with engine off of course, I can rotate the power steering pulley by hand maybe 5-7 degrees each way, with a nice solid elastomeric feel as the damper is twisted & released.

The noise seems to originate from the driver's side engine compartment, around the cover of the trans, but it's very difficult to narrow down. It generally goes away when the engine is warm, & it's always the same frequency and roughly the same engine r.p.m. (not far off idle).

So, as the car is driven, each time it shifts, the engine will pass through that r.p.m., and the rattle reliably shows up briefly. Until it's warmed up, anyway. Very loud.

It's been doing this for maybe 1,500 miles, so it can't be too destructive, or it wouldn't still be running. No engine performance complaints at all.

Sometimes I suspect exhaust shielding. I've pulled & wiggled everything within my reach, and nothing obvious. I had a rock in a Cat shield once, and it behaved similarly... It could also be a loose Cat baffle, but it doesn't sound enclosed in anything.

Since it's gotten slowly louder over time, I decided that it will fail at its own chosen time & identify itself that way. Not sure what else to do that doesn't involve throwing money at a 15 year old car. (Great condition, almost mint, with about 37k).

Reply to
Robert Barr

Possibility that the pickups on the crank sensor have been slightly bent...I'm grasping at straws here! :)

Reply to
Mark Keeling

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.