cshlin

Hey all,

Does anyone's 8 'groan' at low-speed turning manuevers? I seem to notice the problem more when the car is cold, but still happens after warm. I guess it could be steering fluid, but sounds like it's from the suspension because I don't have to be turning the wheel when it happens :/

C

zoom44

yeah you should check your steering fluid....... but first read your manual so you will know how to check it properly

question- how can you be doing a "low speed turning manuever" and yet you "dont have to be turning the wheel when it happens"?

Nubo

I can say with absolute certainty that it is not the steering fluid

There's an early TSB regarding a "snapping" noise during low speed maneuvers, which was caused by slippage between the wheel and hub. That's wheen the torque specifications were increased to (I think) 108 lb-ft for the lug nuts. You might want to check because I haven't torqued them for awhile and may have forgotten the actual value. The TSB also had some stuff about cleaning up the old paint that had been used on the hub, but I didn't have that issue.

Anyway, maybe you have a variant of that problem?

RX8_Buckeye

Sorry Nubo, but it is very likely related to his power steering system. I work as an automotive NVH (noise, vibration, harshness) engineer, and I can tell you that the power steering system produces a variety of noises, usually characterized as grunt, groan/moan, or whine/whistle. The frequencies of these noises are usually integer multiples of the number of vanes in the power steering pump times the pulley ratio of the pump in relation to the crankshaft/e-shaft times the engine speed. During the development of a vehicle, much work is done to tune the power steering lines to attenuate power steering noise, and sometimes changes are made to the pump internals if line tuning is not effective. In a production vehicle that is experiencing excessive power steering noise, there is likely some error state. Some things to check are:

1) Is the power steering fluid level okay?
2) Is there any air in the system?
3) Does the routing of the power steering lines look okay? Check for unclipped lines, unusual bends in flexible parts of the lines, etc.

Usually power steering noise is most noticeable under heavy load, which occurs during idle or low-speed turning. The steering wheel doesn't have to be moving, but if it is close to a lock position (fully turned in one direction or the other), the pump will be producing the most pressure in the system.

zoom44

i cant tell if all of that was
a. true
b. BS or
C. true and BS in this case

RX8_Buckeye

LOL, I'm just trying to share some of my knowledge. I don't claim to know exactly what is causing the noise he is hearing, only that it is VERY possible that the PAS system could be the cause. Likewise, the "snapping" noise due to the wheel/hub slippage that Nubo mentioned could also be a source of noise. The problem is that it is impossible to adequately describe a noise using text. We can only suggest possibilities.

BTW I would be happy to talk more about power steering noise if you still doubt my credibility. :p

zoom44

well you understand that my first answer was wrong on purpose so the op would read his manual and learn a little about his/her car, right? because a power steering pump or fluid could not be the cause in this situation

therm8

Don't want to interupt the fun :D , *snip*. And I'm just aiming for 600 posts


edit: shush therm lets let the OP find the answer for themselves

RX8_Buckeye

I guess we're not on the same page here. Why are you convinced that the fluid or pump couldn't be the source of the noise? I have spent weeks working on vehicles trying to attenuate noises caused by power steering systems. Air in the lines, kinks in the lines, improperly aligned pump internals, etc. are all potential causes of these noises. As I mentioned previously, the wheel doesn't have to be in motion for the power steering pump to be working hard. The condition that causes the greatest pressure in the power steering system (and usually the loudest noises) is while idling when the steering wheel is turned all the way in one direction and held there. This is what I believe cshlin meant when he said "I don't have to be turning the wheel when it happens".

OOPS, I get it now :o . Different type of PAS system than I'm accustomed to working with... DOH! Nubo, Zoom, I apologize for trying to be a know-it-all.

zoom44

hey i know you know what your talking about- and i understand the wanting to defend your expertise that you've worked hard to aquire. no worries

Nubo

'cuz there's no pump or fluid in the RX-8; it's electric - not hydraulic. We should have just came out and said it instead of being coy. Just having a bit of fun about an aspect of the car that sets it apart.

Admittedly, it's a stretch to go from "snapping" to moaning, but that's the only general issue I know of that's been affecting the steering system. Certainly there must still be opportunities for other types of resonances. But it's easy enough to clean up the hubs and retorque the nuts to rule it out.