Conference vmsnet::car$note:carbuffs

    I have a '97 Jeep Cherokee Laredo V8 with about 3800 miles.  I took it
    in monday to get a couple of bugs fixed.
    
    One problem was a high-pitched whine that only appears at 60mph and
    can't be heard by the time I reach 65 mph.  It's difficult to tell if
    it stops at 65 or is simply drowned out by other noises.  The whine is
    not too loud, just irritating and happens to be right in the typical
    driving speed range.  I can hear it all the time on the highway.
    
    It only appears at 60mph, regardless of RPM.  For example, I can lock
    out the OD and increase enging revs from about 2000 to 3000 rpm but the
    whine will still only appear at 60-65 mph.
    
    If I take my foot off the gas at 60, it stops instantly.  It restarts
    instantly if I reapply the gas, providing the speed has not dropped
    below 60 mph.
    
    The local dealership acknowledges that they can hear it but that it is
    "normal" and probably coming from the lockup torque converter. They
    suggest that I run it to 6000 miles and see if it disappears, a
    solution that I'm not really happy about - it was not there during the
    first 1000 miles.
    
    Any GC owners have experience of this noise or have any ideas on what
    this might be?
                  

    at 60mph your converter is most likely locked.. soits not likely to be
    whining.. if the whine doesn't change when you drop out of OD - which
    probably still lets the converter lock, btw - that also seems to point
    away from the converter..
    
    Sounds like a differential to me... (a) related to road speed and (b)
    only under load.
    
    ...tom

    V8?  AWD?  I'd look there first.

Our '95 V8 developed a whine after a couple-three thousand miles. It 
was most noticeable in the 40-50 mph range. If memory serves, it was 
throttle sensitive. Noisier on decel than accel, I think, and most 
noticeable at cruise. Whatever.

It turned out to be the inner bearing races in the front axle - 
meaning those races at the differential end of each axle shaft. There 
were apparently a dozen or so cars that showed up in new England with 
similar problems, which were due (so they said) to improper 
installation.

They replaced the  bearings, and all's been well since. The factory 
apparently got involved at the time (because of the multiple 
reports), and this was a Good Thing. Otherwise I expect I'd still be 
bringing it back while they replaced parts, or claimed to.

Their initial response, by the way, can be summed up in three words:

"It's a truck."

Bruce

	Anyone else see the bit on one of those 20/20/Dateline/Primetime shows
about Cherokees and throttle issues? Apparently, in 1991 vehicles (they seemed
to say GC and Cs) quite a few "runwaway" vehicle accidents are occurring.
Owners claim "I started the thing, put it in drive and it just took off!"...
Mopar claims that it's driver error and that the operator thinks their foot
is on the brake when in fact it's on the gas. Apparently the gas and brake
pedal are considerably further to the left than most vehicles because of the
Cherokee's large tranny hump.

	Later years have a lockout that does not allow shifting into drive w/o
a foot on the brake and a "We'll fix it, but it ain't a recall" program is
currently going on.

	I found it quite interesting.... If a driver did find himself in the
position that Mopar claims I don't think their first reaction would be to look
down and check which pedal their foot is really on. I'm pretty sure I'd assume
my foot was on the brake. The real clincher in support of Chrysler's theory is
that even with the truck floored, it can be stopped. While the accident victims
were saying "it didn't matter how hard I pushed on the "brake", the truck would
not stop.

Rick

    That sounds like exactly the same thing that some Audi 5000 owners
    complained about afew few years back. Some people believe the
    "unintended acceleration" to have been a real problem, others (
    including Audi ) content that the drivers had their foot on the
    accelerator, but thought it was on the brake. Audi did a "fix", changed
    pedal positions, installed lockouts etc. It really hurt them
    financially, and their reputation in some eyes.
    
    Steve
    

    ya but the clincher in both cases was the brake pedal
    physical location.  They showed the Cherokee and audi 
    
    to have the right edge of the bp almost in line withthe
    center of the steering wheel whereas most cars have the right
    edge of the bp offset up to 4" to the right of the
    steering wheel center line. So I hop in my VW and sure enough
    the edge of the BP is approx. 4" to the right of the SW centerline.
    I also noticed that I tend to use the right side of the BP. Now
    If I were to hop into one of those Jeeps or audis with the
    malaligned pedals I think it would be easy to step on the gas
    by mistake.  they also said there were a significant number of
    accidents where the driver just recently bought the vehicle.
    
    
    		Dean_who_only_witnesses_intended_accelleration

>    That sounds like exactly the same thing that some Audi 5000 
owners
>    complained about afew few years back. Some people believe the
>    "unintended acceleration" to have been a real problem, others (
>    including Audi ) content that the drivers had their foot on the
>    accelerator, but thought it was on the brake. Audi did a "fix", 
changed
>    pedal positions, installed lockouts etc. It really hurt them
>    financially, and their reputation in some eyes.

Three (3) governments published their official findings on the Audi 
matter, and all three (the U.S., Canada and Japan) agreed with Audi. 
The U.S. report, written in official government gibberish, said 
"pedal misapplication". :-) Of course, "60 Minutes" didn't give the 
north end of a south running rat about those reports, since it wasn't 
really a grabber of a story. Nor did they think the leader of the 
"Audi Victims' Society" (or somesuch) was worth a story when her case 
was not only thrown out of court, but she was fined for bringing a 
frivolus suit.

They already had their story, and it had been a great one for them. 
Of course, it was bullsh*t, but hey, you should have seen the ratings 
share :-).

Bruce

I have had two efi cars which have exhibited this same charcteristic of
unintended acceleration ... In absolutely no circumstances was my foot on the
wrong pedal ... both occured with NO feet on the pedals!

Both occured when engaging drive on two different Renaults ... an Alliance
and a Medallion.  Both will increase the idle when engaging drive slightly
but on two occasions they increased the speed significantly that it was
a real surprise.  The engine computers for these cars are significantly
different so there is no direct link.

So, as much as the manufacturers say "It cannot happen" ... I don't believe
them!

Stuart

> So, as much as the manufacturers say "It cannot happen" ... I don't 
believe
> them!

AFAIK, the manufacturers have all said very little about engine 
speedups. What they've said can't happen (or at least hasn't 
happened) is the ability for the car to overpower its own brakes 
during such an event - a different thing entirely.

Bruce

Right. My wife had an experience with an Audi Fox years ago where its 
accelerator got stuck ... she had no problem stopping it with the brake.

I've got a Grand Cherokee as well as a Lexus sedan, and I do notice that 
my normal brake foot position is on the right half of the pedal in the
Jeep and dead center in the Lexus, indicating that the Jeep does have the
pedals further to the left. 

I have a little trouble imagining getting confused about what pedal you're
pushing, though, since the accelerator and brake pedals follow different 
trajectories due to the way their linkages work. I guess if you're in a blind 
panic, you don't necessarily notice the finer distinctions...

Intelligent people swear they can't be fooled ... tell that to the folks
up on the UFO behind Hale-Bopp...

    Thanks for the input on the noise.  I'll get it checked out when.
    I take the car in for the unusual noises that appeared _this_ week.   
    
    Colin
    
                                      

Speaking of cars overpowering their own brakes ...

My caravoyager went in for tranny work and in the process of the repair, the
dealer did something to the throttle / cruise control linkages such that from
time to time, the cruise control would cable sheath would pop out of the
vacuum control, putting a tension on the cable, resulting in a very high
idle (2000 rpm or so).

The symptom would show when driving as when coming to a stop, with the change
down into first, suddenly you'd feel like you had a kick in the pants, and
have to apply the brakes very hard ... a couple times I had to floor the
brake pedal to get the thing to stop in time.  The rest of the time, the
brakes behave quite within "expectations" ... although this suggests that
they do need some attention.

This certainly comes close to a vehicle overpowering its brakes.

Stuart

    
    
    	I had a 1976 CJ7 that would overpower the brakes, no problem.
    Almost drove me into a wall one day. Eeeks...
    
    

Perhaps I should've said something in regard to cars having healthy 
brakes?

Nope. Forget it. It's self-evident, except in a court of law, of 
course. :-)

Bruce

    Anytime you give control of the motor to something other than a cable
    hooked to the pedal you are asking for trouble, IMO.
    
    A friend and I had identical Ford LTD Wagons, and while his wife was
    driving his one day, "a sensor" became defective and the acceleration
    was intense (according to her). The Ford Dealer said it was a
    temperature sensor and the computer decided that the motor was
    stone-cold, and decided to go ballistic. She popped the transmission
    into nuetral to avoid nailing the car in front of her, and got some
    serious RPM out of that V6. Mine never did that, but it was always in
    the back of my mind.
    
    The pedal offset theory is interesting, but I suspect it ain't the
    only one...
    
    .mike.

Great story on 20/20. At least they told both sides. Loved the one about going up the garage stairs into the 
living room (it goes up a flight of stairs easier than my dear old mom). "Victim's" experience with Jeeps?  3 weeks.  
No these people are not nuts, but they can't believe they could have possibly screwed up.
What they need is a dump of CPU showing full throttle possition and zero brake fluid presure to the ABS system.
And still they will argue.  I mean 50 cases when Jeep cranks 1,500,000 units a year??? Come on....

<Set engineering cap on >
As with the Audi, the bottom line is that we are talking about 4 massive disk brakes. If you actually  are on the 
brakes and then push the accellator to the floor, the engine will stall or the torque converter will blow up.
Instead, now Jeeps too will be getting an interlock. Note rocking between forward and reverse when
stuck will become a lot harder.  Maybe they will have an idiot override if you order the upcountry trail package.

john

200,000 trouble free jeep miles

Great story on 20/20. At least they told both sides. Loved the one about going
up the garage stairs into the  living room (it goes up a flight of stairs
easier than my dear old mom). "Victim's" experience with Jeeps?  3 weeks.   No
these people are not nuts, but they can't believe they could have possibly
screwed up. What they need is a dump of CPU showing full throttle possition and
zero brake fluid presure to the ABS system. And still they will argue.  I mean
50 cases when Jeep cranks 1,500,000 units a year??? Come on....

<Set engineering cap on >
As with the Audi, the bottom line is that we are talking about 4 massive disk
brakes. If you actually  are on the  brakes and then push the accellator to the
floor, the engine will stall or the torque converter will blow up. Instead, now
Jeeps too will be getting an interlock. Note rocking between forward and
reverse when stuck will become a lot harder.  Maybe they will have an idiot
override if you order the upcountry trail package.

john

200,000 trouble free jeep miles