Engine clunking noise when the steering wheel is turned - power steering?
03-21-2009, 01:49 PM
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Engine clunking noise when the steering wheel is turned - power steering?
Hey,
my 1996 993 with 125 k miles started to make this terrible knocking noise when i turned the wheel to the far left or right. it is coming from the back right part of the engine compartment. i believe it is the power steering. it just got tons worse today, if i turn the wheel at all it makes the ugly noise.
question is does this sound familiar? is this indicative of a power steering type problem? if so, is the power steering an easy fix or is it a shop worthy repair? i've done my brakes, suspension and some other stuff but this is new to me.
i looked at pcarworkshop but did't see anything specific to this problem. p-car dot com doesn't appear to be working (at least on my computer). when i typed in power steering on rennlist i received several postings but none of them appear to address this specific problem.
as usual i really appreciate all your help.
regards,
josh
my 1996 993 with 125 k miles started to make this terrible knocking noise when i turned the wheel to the far left or right. it is coming from the back right part of the engine compartment. i believe it is the power steering. it just got tons worse today, if i turn the wheel at all it makes the ugly noise.
question is does this sound familiar? is this indicative of a power steering type problem? if so, is the power steering an easy fix or is it a shop worthy repair? i've done my brakes, suspension and some other stuff but this is new to me.
i looked at pcarworkshop but did't see anything specific to this problem. p-car dot com doesn't appear to be working (at least on my computer). when i typed in power steering on rennlist i received several postings but none of them appear to address this specific problem.
as usual i really appreciate all your help.
regards,
josh
03-21-2009, 02:34 PM
#2
Three Wheelin'
Sounds like somethng is loose, be it the pump, a pulley, or the housing. Open up the engine compartment, find the power steering fluid tank on the right side, and follow the lines to the pump. If you can have someone turn the wheel with it running while you watch, see if you can hear any better. And make sure you check the fluid in the tank, though I can't see that making a thunking noise. Working on the power steering system isn't that hard, but getting access can be. I think you can access the belt and pulley's in the car, but it is a pain in the ***. My motor is out at the moment, so I am doing everything I can in that area now.
03-21-2009, 05:37 PM
#3
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Check the PS fluid reservoir level ASAP: the PS pump will scream a blood curdling chatter, even at idle, if fluid is too low ..... turning off center is the precursor to that, so catch it before $$$$$ pump damage.
If the level is low, 95% odds the PS rack is blown.
If the level is low, 95% odds the PS rack is blown.
03-22-2009, 11:59 AM
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BUT the reason the fluid was low is that I had a leaking rack as well. Just replaced it a couple of weeks back. They are expensive and rebuilt racks are hard to come by.
03-22-2009, 01:20 PM
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you all are officially making me sick to my stomach. so i left the car at my mechanic(the swiss garage in houston) yesterday and am afraid they will jack it up more before figuring out the problem. i like and trust them but they are a shop and this is a source of revenue. tempted to jump the fence to see if i can fix it before they get to it. afraid i really messed up the ps and do not want to spend $3 - $5 k on a new power steering system because i am a moron. thanks for the insight and help ... think i am going to go throw up, cry for a while and suck my thumb.
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03-22-2009, 10:45 PM
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Didn't mean to drive you to gastric duress ... but a leaking rack is inevitable in these cars, and is the most common cause of the reservoir level dropping: a too low reservoir causes the pump to cavitate, creating a hell of a noise. A way too low level results in metal on metal .... 
These pumps are very tight tolerance, and are lubed by the PS fluid .... so don't last long running dry ( ditto with fuel pumps). Anyway, I would start by topping up the fluid and starting the engine to see if that killed the noise ...... and more importantly, to verify that the pump is OK.
Next, get under the front axle area, and slide a screwdriver under the tierod side of the rack boots: if they are full of fluid, the rack is dead.
Assuming that to be an outcome, I would flush the system well with ***cheap Dexron III when taking the rack out ( by running the engine while pouring into the reservoir with lines cracked open at the rack) . This step is to flush out any potential grindings from the PS pump, just in case the noises you heard were metal on metal, and not just fluid cavitation: the objective being to preserve the $$$ pump, which requires an $$engine$$ drop to otherwise R&R.
*** Dexron III , at $3/liter is compatible with the $20+/l stuff the system is eventually filled with - so is great for flushing.
Regardless, hope it is something simple; however, if it is the rack, perhaps some of this will help.
These pumps are very tight tolerance, and are lubed by the PS fluid .... so don't last long running dry ( ditto with fuel pumps). Anyway, I would start by topping up the fluid and starting the engine to see if that killed the noise ...... and more importantly, to verify that the pump is OK.
Next, get under the front axle area, and slide a screwdriver under the tierod side of the rack boots: if they are full of fluid, the rack is dead.
Assuming that to be an outcome, I would flush the system well with ***cheap Dexron III when taking the rack out ( by running the engine while pouring into the reservoir with lines cracked open at the rack) . This step is to flush out any potential grindings from the PS pump, just in case the noises you heard were metal on metal, and not just fluid cavitation: the objective being to preserve the $$$ pump, which requires an $$engine$$ drop to otherwise R&R.
*** Dexron III , at $3/liter is compatible with the $20+/l stuff the system is eventually filled with - so is great for flushing.
Regardless, hope it is something simple; however, if it is the rack, perhaps some of this will help.
03-23-2009, 01:44 AM
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thanks again ... going to call the mechanic first thing in the morning and tell himm to hold off on doing anything to the vehicle other than changing the oil. my guess is the pump is fubar'd ... it started making the noise a couple weeks go but didn't sound real bad till yesterday. will let you know what i find out.
04-11-2009, 01:59 PM
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debrief ... so i have now learned that the power steering pump has a belt and apparently this belt was what was causing the noise. i feel kinda like an idiot but it took the mechanic some time to figure this out too so maybe i am not so dumb.
a quick follow-up question. my rack went out this morning on the way to school. fluid leaking everywhere. when swiss garage worked on my car they flushed the lines. what i am wondering is if they could have jacked up my car when they flushed the lines and changed the resovoir. i didn't have a single problem with the car till this morning and have only driven it a couple times since getting it back from them 2 weeks ago.
thanks again for all your help.
josh
a quick follow-up question. my rack went out this morning on the way to school. fluid leaking everywhere. when swiss garage worked on my car they flushed the lines. what i am wondering is if they could have jacked up my car when they flushed the lines and changed the resovoir. i didn't have a single problem with the car till this morning and have only driven it a couple times since getting it back from them 2 weeks ago.
thanks again for all your help.
josh
04-11-2009, 08:13 PM
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Not trying to be a Sherlock Holmes smart a$$ ..... but why was the PS belt making noises??? ..... and was it entirely by coincidence that the rack lost its cookies within a few miles of driving after the 'noises'?
Anyway, any brief moments of low PS fluid level would have caused metal on metal impeller contact ..... which causes both duress to the belt, and sends metal shavings into the rack (seals). Mind you, that is all worst case scenario; however, I would ask your wrench exactly why was the (toothed) PS drive belt acting up?
Anyway, any brief moments of low PS fluid level would have caused metal on metal impeller contact ..... which causes both duress to the belt, and sends metal shavings into the rack (seals). Mind you, that is all worst case scenario; however, I would ask your wrench exactly why was the (toothed) PS drive belt acting up?
04-12-2009, 08:46 PM
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good questions and here are the answers ...
took the car in cause it was making this terrible noise when i turned the steering wheel. after 4 hours of labor thewy figured out it was the belt. there comment was the belt had lost some teeth and was skipping on the pulley. what i don't know is if the pulley is anywhere near a point where particulates could enter the fluid lines to csuse a catastrophic failure.
this discovery was made after removing the power steering pump to inspect it, flushing the lines and changing the resevoir/ filter and wasting time to charge up hours. prior to this there was nothing, not a drop leaking out of the rack ... the mechanic even commented that the car is in great shape.
my hypothesis is that the mechanic did something that caused particulate to enter the system causing a catastrophic failure of the rack within a couple hundred miles of the operation.
what do you think? did swiss auto jack it up?
took the car in cause it was making this terrible noise when i turned the steering wheel. after 4 hours of labor thewy figured out it was the belt. there comment was the belt had lost some teeth and was skipping on the pulley. what i don't know is if the pulley is anywhere near a point where particulates could enter the fluid lines to csuse a catastrophic failure.
this discovery was made after removing the power steering pump to inspect it, flushing the lines and changing the resevoir/ filter and wasting time to charge up hours. prior to this there was nothing, not a drop leaking out of the rack ... the mechanic even commented that the car is in great shape.
my hypothesis is that the mechanic did something that caused particulate to enter the system causing a catastrophic failure of the rack within a couple hundred miles of the operation.
what do you think? did swiss auto jack it up?
04-12-2009, 09:37 PM
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My comments arise from having a low tolerance for coincidence .... normally in issues of mechanical failure, there is a discernable sequence of events: AFAIK, the PS toothed drive belt is incredibly robust, and rarely fails in service - so is not the primary element in this failure sequence ( yes, many belts are replaced as preventive maintenance items; however, has anyone witnessed a failure due to stripped teeth simply due to an ageing belt? .... in an otherwise healthy system?). Instead, think of the cam drive gear trying to apply torque to this belt to turn a pump that prefers not to turn ....
Consquently, it is the reverse that comes to mind .... the loss of lubrication via low PS fluid level causes the tight tolerance PS pump to make ( grinding) contact between the impellers. A horrific noise ensues as metal filings are produced .... these filings are pumped into the steering rack at ~ 100 bar pressure (1500 psig), and do the nasty with the delicate internal high pressure seals ..... the fluid fills the chambers, passes the lp seals and fills the rack boots to overflowing .... which knocks the reservoir level lower ( again), etc. as the cycle repeats.
That the rack failed so soon following the belt repair is the unacceptable coincidence to my delicate sensibilities - recognizing that this is a very remote diagnosis with all the internet limitations.
If the PS pump is still producing good pressure, great news! That the lines were flushed - great! also, replacing the reservoir is 'mandatory' as there is a non servicable internal filter on the return flow side.
If a new rack were to be installed, I would pull the DME relay, and run a gallon of cheap Dexron III through the system using the starter motor in bursts so as to fully flush the lines: I would then toss the $35 for another fresh reservoir, as that cost palls in comparison to PS pumps and racks .... and fill up with the CF 11S juice.
In short, I suspect that your wrench is innocent of screwing things up to cause the rack failure ...... I would, however, contest the diagnosis that led to this situation.
If it would make more sense to see the PS pump and drive belt, I can take a pic of one with the belt cover removed - tomorrow
Consquently, it is the reverse that comes to mind .... the loss of lubrication via low PS fluid level causes the tight tolerance PS pump to make ( grinding) contact between the impellers. A horrific noise ensues as metal filings are produced .... these filings are pumped into the steering rack at ~ 100 bar pressure (1500 psig), and do the nasty with the delicate internal high pressure seals ..... the fluid fills the chambers, passes the lp seals and fills the rack boots to overflowing .... which knocks the reservoir level lower ( again), etc. as the cycle repeats.
That the rack failed so soon following the belt repair is the unacceptable coincidence to my delicate sensibilities - recognizing that this is a very remote diagnosis with all the internet limitations.
If the PS pump is still producing good pressure, great news! That the lines were flushed - great! also, replacing the reservoir is 'mandatory' as there is a non servicable internal filter on the return flow side.
If a new rack were to be installed, I would pull the DME relay, and run a gallon of cheap Dexron III through the system using the starter motor in bursts so as to fully flush the lines: I would then toss the $35 for another fresh reservoir, as that cost palls in comparison to PS pumps and racks .... and fill up with the CF 11S juice.
In short, I suspect that your wrench is innocent of screwing things up to cause the rack failure ...... I would, however, contest the diagnosis that led to this situation.
If it would make more sense to see the PS pump and drive belt, I can take a pic of one with the belt cover removed - tomorrow
04-12-2009, 10:43 PM
#14
Seared
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My comments arise from having a low tolerance for coincidence .... normally in issues of mechanical failure, there is a discernable sequence of events: AFAIK, the PS toothed drive belt is incredibly robust, and rarely fails in service - so is not the primary element in this failure sequence ( yes, many belts are replaced as preventive maintenance items; however, has anyone witnessed a failure due to stripped teeth simply due to an ageing belt? .... in an otherwise healthy system?). Instead, think of the cam drive gear trying to apply torque to this belt to turn a pump that prefers not to turn ....
Consquently, it is the reverse that comes to mind .... the loss of lubrication via low PS fluid level causes the tight tolerance PS pump to make ( grinding) contact between the impellers. A horrific noise ensues as metal filings are produced .... these filings are pumped into the steering rack at ~ 100 bar pressure (1500 psig), and do the nasty with the delicate internal high pressure seals ..... the fluid fills the chambers, passes the lp seals and fills the rack boots to overflowing .... which knocks the reservoir level lower ( again), etc. as the cycle repeats.
That the rack failed so soon following the belt repair is the unacceptable coincidence to my delicate sensibilities - recognizing that this is a very remote diagnosis with all the internet limitations.
If the PS pump is still producing good pressure, great news! That the lines were flushed - great! also, replacing the reservoir is 'mandatory' as there is a non servicable internal filter on the return flow side.
If a new rack were to be installed, I would pull the DME relay, and run a gallon of cheap Dexron III through the system using the starter motor in bursts so as to fully flush the lines: I would then toss the $35 for another fresh reservoir, as that cost palls in comparison to PS pumps and racks .... and fill up with the CF 11S juice.
In short, I suspect that your wrench is innocent of screwing things up to cause the rack failure ...... I would, however, contest the diagnosis that led to this situation.
If it would make more sense to see the PS pump and drive belt, I can take a pic of one with the belt cover removed - tomorrow
Consquently, it is the reverse that comes to mind .... the loss of lubrication via low PS fluid level causes the tight tolerance PS pump to make ( grinding) contact between the impellers. A horrific noise ensues as metal filings are produced .... these filings are pumped into the steering rack at ~ 100 bar pressure (1500 psig), and do the nasty with the delicate internal high pressure seals ..... the fluid fills the chambers, passes the lp seals and fills the rack boots to overflowing .... which knocks the reservoir level lower ( again), etc. as the cycle repeats.
That the rack failed so soon following the belt repair is the unacceptable coincidence to my delicate sensibilities - recognizing that this is a very remote diagnosis with all the internet limitations.
If the PS pump is still producing good pressure, great news! That the lines were flushed - great! also, replacing the reservoir is 'mandatory' as there is a non servicable internal filter on the return flow side.
If a new rack were to be installed, I would pull the DME relay, and run a gallon of cheap Dexron III through the system using the starter motor in bursts so as to fully flush the lines: I would then toss the $35 for another fresh reservoir, as that cost palls in comparison to PS pumps and racks .... and fill up with the CF 11S juice.
In short, I suspect that your wrench is innocent of screwing things up to cause the rack failure ...... I would, however, contest the diagnosis that led to this situation.
If it would make more sense to see the PS pump and drive belt, I can take a pic of one with the belt cover removed - tomorrow
Nothing short of, "awesome". Excellent write-up.
Andreas
04-13-2009, 02:46 PM
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once again, thank you for the feedback.
the way my wrench described it is the lack of teeth caused the pressure in the line to fluxuate significantly which he believes weakened the seals compromising their integrity.
no matter what i need to replace the rack. the wrech gave me two options: 1) rebuild the current rack for $1600 or get a new one for $2300. question i have is what you all would recommen, rebuild vs new.
next, is replacing the something that you would recommend someone do on their own. the wrench is charging $700 in labor and i have access to tools and a place to work on it. time is also not an issue because i happened to buy a 1983 chevy s-10 pick-up truck for $1500 the day my porsche originally bit it. sometimes i think paying for work is good if it is overly complicated. i think this repair will cost me a couplle hundred dollars for parts, equipment and 'otj learnings' plus 2 days of my life.
thoughts, opinions, concerns?
as always i thank you for your help.
josh
the way my wrench described it is the lack of teeth caused the pressure in the line to fluxuate significantly which he believes weakened the seals compromising their integrity.
no matter what i need to replace the rack. the wrech gave me two options: 1) rebuild the current rack for $1600 or get a new one for $2300. question i have is what you all would recommen, rebuild vs new.
next, is replacing the something that you would recommend someone do on their own. the wrench is charging $700 in labor and i have access to tools and a place to work on it. time is also not an issue because i happened to buy a 1983 chevy s-10 pick-up truck for $1500 the day my porsche originally bit it. sometimes i think paying for work is good if it is overly complicated. i think this repair will cost me a couplle hundred dollars for parts, equipment and 'otj learnings' plus 2 days of my life.
thoughts, opinions, concerns?
as always i thank you for your help.
josh