Got a Quick, Technical Question?

Mr_Shiftright

well unless you're made of metal you aren't going to draw any amperage out of a 12V battery...but you're right you can run 10,000 volts through yourself probably with miniscule amps.

Volts matter as regards electrical "force"....our bodies just aren't that good a conductor...

Anyway, here's what the car talk guys say about it---maybe you can get a little "tingle" out of a 12V battery after all!

http://seattlepi.nwsource.com/wheels/269701_talk12.html

user777

well shifty, if the car talk guys say it isn't so, should i believe them? after all, they are MIT engineers. :shades:

the resistance your body presents to the battery is a function of many of the things i already mentioned before. if your skin is very dry, chances are the resistance will be orders different (more) than if you are perspiring (where it will go down). when dry, your skin presents fairly high resistance to a voltage source, and therefore not much current flows. But, if you perspire, the equation (values, not relationship) changes.

I = V / R is what it is - it's not a theoretical vs. real-world concept as the entertainers on the talk radio make it out to be. No offense intended; i'm sure they've probably forgotten more about vehicles than I'll ever learn about them.

I know, if R decreases with V fixed, the current flowing in a circuit increases. Get R (the resistance in ohms) in the correct range, and the I (the current in amps) can result in a shock.

When I'm disconnecting a car battery, I'll continue to remove the (-) first and when re-installing, connect the (-) last. Maybe I'm being overly cautious, but maybe I'm not. There's nothing to be ashamed about if you exercise caution.

I really hope we might dispell the notion though that it's the voltage that bites you. It's the current, and it's the current path through the body which influences the outcome of an event. Is there by chance a cardiologist who happens to be a car geek lurking here in edmunds land who would confirm this for us?

I like the point made by bolivar on the current the battery is capable of delivering into a small resistance and the risk of bodily burns / injury.

regards.

stryped

Hey,

My wife has a 99 Malibu. It has a "noise" while driving that is hard to explain. ALmost like a roar. It is not too loud. To me it sounds like it is coming from the right front wheel. It is there even if while cruising you put the car in neutral. It seems to go up in pitch as you get faster and go down as you get slower. I rotated all the tires to see if that would help, (putting the front tires in the back and the back into the front). It did not seem to help very much. I also took the break pads off and cleaned then and the rotors. There was plenty of padding left on the brakes.

I did notice that while cruising at highway speed if I turn the wheel to the right I can make it a little louder while turing.

ANy idea what this would be and how to tell? My guess might be a cv joint? My Hayes manual says a symptom of that is clicking or grinding while turning but this does not sound exactly like that.

By the way I also with the car jacked up pulled on the wheel before taking it off and did not feel any play. (I thought that was the right way to tell if a wheel bearing was bad.)

I have never messed with a front wheel drive car very much so I am not sure how difficult it would be to replace if this was it. Autozone has a unit for 70 bucks. What is involved in replacing one? (If that is my problem).

Also, on this 96 Chevy truck I noticed I have a coolant leak that is difficult to find out where. Last year I had the radiator checked and plugged. But it does not seem to be coming from there. I feel "wetness" On the water pump outlet to the lower radiator hose. I think the hose is only 1 year old. "Replaced it when I took the radiator out."

Could it be leaking where the water pump bolts to the block? Every other water pump I have had go out it would leak out the weep hole. Maybe the water pump bolts have loosened causing it to leak where it meets the block?

Anyhow I appreciate your advice and Merry Christmas to you and your family!

Don

qbrozen

obviously you didn't have braces

does ANY 4-year-old have braces? ;b

qbrozen

sounds like a bearing.

stryped

A wheel bearing? How can I tell?

qbrozen

well, you can jack up that wheel and try wiggling it, but that might not tell you anything. You should get a vibration if the bearing wiggles. But you can get grinding without wiggling on a bad bearing. You may hear the grinding by spinning the wheel while jacked up ... but you may not. I might take the weight of the car on it to cause the noise. All you can do is try.

The question you should be asking is, "what else could it be?" As you said, a CV gives different symptoms. You've checked the brakes. So I'm not sure what else it could be.

imidazol97

If the car has a front wheel bearing going bad, when you turn to the right that throws weight onto the left front and if the noise increases that's the side with the bad bearing.

Elsewhere I've read that if you jack up the car under the body with the regular jack and spring the wheel you can feel the bad bearing by putting your hand on the front bumper. I'm not sure you're going to feel looseness. It's the bearing surface that has a bad spot instead of wear along the ends of the bearings that would leave more looseness.

If it's a rough growl and you feel it in your feet and the steering wheel that would match my 93 when it had a bad bearing at about 80 something K miles.

stryped

the sound is kind of a howling. No vibration that I can tell.

I jacked it up and could not feel the tire "move" when pulling.

Any ideas guys? The car has 94,000 miles. Is it hard or expensive to change the bearings? I have changed wheel bearings before, but it has been awhile and was always in a rear wheel drive car.

I can make it worse for a second by turning the wheel quickly to the right at highway speeds. This is my wife's car.

qbrozen

its definitely more difficult on a FWD car. Its not terribly expensive, though. I had a shop do my volvo for $350. The biggest difference would be whether the bearing can be changed or if the whole hub needs to be replaced. $350 on the volvo was for the whole hub.

stryped

I am wanting to do this myself but I would like to know that that is definitely the problem. How can I do that?

By the way, to me the sound sounds similar to a truck with mud tires going down the road at highway speeds but no vibration.

qbrozen

I really can't answer the question.

In car repairs, guarantees are not always made. Sometimes, all you can do is take all of the symptoms into account, eliminate as many possibilities as possible, and make your best guess. Sometimes, the only way to know for sure is to make the repair. If it cures it, you know you were right.

Oh, and when doing the old "let's do this and see what happens" method, start with small stuff first. If you are doing it yourself, the part shouldn't be too expensive (just don't buy it from the dealer). So, worst case, it eliminates one of the possibilities and only cost you a couple hundred bucks at the most.

By the way, did you get to spin the wheel while jacked up in the air. Obviously, you want to make sure nothing is rubbing while turning. Brake shields, for instance, have been known to get out of whack and rub.

Mr_Shiftright

You can't tell for certain unless you have the bearing out, cleaned up and in your hand....but it sounds like a good guess. A CV joint would probably "knock" on hard turns.

imidazol97

Any chance it's a rear bearing? Can it be the differential gears inside the transmission box? Can you jack up one front wheel, thoroughly block other wheels and slowly rotate the wheel with the motor and feel the trans housing and the frame/A arm near the wheel to diagnose?

I took mine to the dealer and the mechanic who test drove it with me commented that it was a whole hub replacement on that model year and that I could do it myself lots cheaper. He almost implied he'd to it at home for me.

He did the diagnosis by swerving left and right.

I did have X-One tires on the car that had hardened the rubber with age ( all tires do ) and had developed a sound just like a front bearing--even with vibration from the front. I put them on the back and still heard the noise from the tread on one or both tires.

Mud tread tires on a work truck is a good description of my bearing on the 93 leSabre.

stryped

I can try to jack up again. I just called and this is a whole hub replacement. It is 98 bucks at autozone. How did he swerve left to right, I mean did it sound worse swerving?

Was this a car similar to mine?

It is funny, we just bought new tires for this about 6 months ago.

What is involved replaing the hub?

imidazol97

I found a couple of explanations. For a 97 it said a 35 or 36 mm socket for the hub bolt (rented from Autozone). There are three bolts behind that first that get loosens with a T-55 Torx and then you work on the 35/36 mm socket. You put something under the end of the wrench at the hub so it won't drop down and then put an extra long bar or pipe on the socket and stand on it to loosen. The torque spec is 284 lb ft for that model he was working on. Do not use an air wrench because of damage to the wheel speed sensor for ABS that's there.

Someone on a 2000 had to use a wheel puller to pull the hub off the axle--those are available for Autozone he thinks. You might price the job at a local, quality mechanic to see if it's worth all the trouble for yourself. One post said there was a cap or something over the 35/36 mm nut like a dust cap or something.

If you do a lot of your own work you might check into a factory service manual for the specific car. I'd suggest Helminc. They have a half price sale until December 31. malibu service manual
I've bought them with each new car (almost) through the years from 1977 Cutlass on. They're much better than Motor or the other one that's a cross general manual, in my opinion.

You might check websites loike Autozone and pepboys for their repair help sections. One might talk about wheel bearings.

For all the work I'd want to know that bearing was the one giving problems. I had seen mention of a transaxle bearing or gear making a noise on the Bonneville 60 and 65 model transmissions. That's why I suggest being able to feel the vibration or looseness before replacing. The one inside the transaxle housing also is repairable but more work.

dodgekbad

Basically the remote key does not unlock the doors or deactivate the alarm. And now I either froes something or the battery is dead because I can't do anything, and the lights don't work.

Does anyone know if I have to "re-program" my remotes or whatever, for an old Clifford Alarm? I have this alarm on there, I don't know what it is, or who put it in (I got the car used at auction).

I tried using the spare key once when I couldn't find my other ones, and ever since then it sems like the remote ket doesn't work. But I've switched keys before and had no problems, and never had to re-program anything.

stryped

Thanks! How would I put 284 ft/lbs of force on that thing? I had a cheapy tork wrench but it does not go that high.

I am with you, I would like to find out exactly what it is before fixing it. I can try to jack it up again but I really can feel a vibration from inside the car, just a noise.

qbrozen

How would I put 284 ft/lbs of force on that thing?

That was gonna be my question!

Heck, I have an expensive torque wrench borrowed temporarily from my father and that doesn't go nearly that high, either.

I do my own work, too, but I read up on changing the hub on the volvo and determined it was not worth it. I believe the part was nearly $200, so paying the shop $350 was not that tough of a decision for me.

imidazol97

If you double the length of the torque wrench with an extension, you are doubling the reading. There are extensions that the torque wrench end fits into.

A neighbor up the road does lots of mechanic work and he just sort of eyeballs it with a pipe on the end of a regular socket. If you use a total of 3 feet, then you would push down with 75 pounds of force. 75 X 3 = 285.

I'm with letting the quality guy who does it a couple times a week change it out. I had the dealer do mine because they give free loaners off the used car lot if you bought yours there and we needed the loaner since we both were working.

qbrozen

HUH?

I don't see how that works ... how does the wrench know you put an extension on it? And, it it did, wouldn't the "click" point change based on where you are holding the wrench? Granted, I'm not an engineer, but I'm just not seeing this. Is there a reference I can read?

I understand what you are saying regarding force. But with a torque wrench that clicks based on the force at the head, I don't see how this can work. 100 lbs on a torque wrench should always click at 100 lbs.

bolivar

I would not load a tork wrench above it's top capacity. Might never be anywhere correct in the future.

I think a nut on my 94 Ranger front suspension was about that value. I just used a breaker bar with a pipe extension and pulled with all I could pull. That seemed like 284ft/lbs to me. Nothing came loose in the years after that.

imidazol97

using extensions and calculating effective torque at nut
another

qbrozen

AAHHHHh... ok. The extension is on the head, not the handle. That makes sense.

stryped

Where are you reading about a bearing hub replacement on a Malibu? This is a 99. So you say the axlenut is 35 mm? My Hayes manual said you have to have a u joint socket to remove the back up bolt that mount the hub to the steering knuckle. What is a "u joint socker"?

qbrozen

i think they mean what is also called a swivel socket. The reason for using this tool is to get to a nut in a tight space.

ok ... here ya go:
http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=3184&group_ID=362&- store=snapon-store&dir=catalog

stryped

I have a swivle adapter that you put a socket on. WIll this work?

qbrozen

i have no idea. it will serve the purpose, but i can't tell you if it will fit where needed in this case.

thewraith

I have an '05 Chrysler T&C Touring. While on a trip, the instrument cluster went out. I limped into the nearest Chrysler dealership, and asked their service dept to look at it. They said there was no power on the B+ feed from the PCM. They spliced into the wire harness and added a feed from the alternator output. They tested it, and the instrument cluster worked, but then the accessories did not.
I ended up having to rent a van for the remainder of my trip, so they could finish the repair. When I got my van back, it seemed to work. I went about 100 miles, then the same thing happened. I took it to another dealership, where they said the PCM was shot. They replaced that, and said that the Chrysler engineers told them to replace the RCM as well, which they did not have in stock. The van seems to work fine now.
What would cause this, and is it "normal" for this to give out in that fashion? I read somewhere that the PCM has a federally mandated warranty of 80,000 miles which would be good news for me, as my van has 49,000 miles on it, and is outside of the mfr warranty.
Thanks in advance!

user777

PCM stands for PowerTrain Control Module and RCM for Restraint Control Module. The former manages the transmission (maybe more in a Chrysler...I don't know), and the latter stands for Restraint Control Module and is part of the airbag and seatbelt tensior safety systems.

Try Googling these to find out more.

jij

Is the BCM on a 2002 Rendezvous something which can be replaced without going to a garage? Where can I get the repair/service manual for this car?

imidazol97

The service manual that's best is Helm Inc which prints the manuals for GM and many other companies.

http://www.helminc.com

ray80

The physical replacement you could most likely do, but supposedly it has to be programmed by dealer to work properly. What is happening that makes you think about replacement?

bkhamdiev

Is there a quick/simple way to disable the seat heater of a 99 Chevy Suburban (6 way power buckets) because mine got really hot and then started smoking while I was driving. It had been getting hotter and hotter lately, and this time, a small hole burned through from underneath. I obviously won't ever turn it on again, but want to completly disable this switch so it won't be turned on accidentally if someone else uses my car. Dealer was no help--wants to sell me new seat. I want to still be able to use the other power functions for adjusting the seat if possible. Cannot find the answer anywhere!

rgarrison

Having a problem with top end speed and limited rpm on a 2000 Kia sportage.

jij

A couple of times, the electrical system on the car went haywire. The headlights came ON, tail lamps went out, the doors won't lock, the stereo got locked and the SECURITY message lighted on the dashboard. Both time, I removed the BCM fuse and fixed it in and the problems disappeared. Apparently, lots of owners of 02 Rendezvous have faced similar problems and in each instance the dealer diagonized it to be a BCM related issue.

ray80

I've heard of that happening on the Pontiac version a couple times. Assuming the vous starts ok and battery is good, you might want to check the hot connection from battery to undehood fuse box to make sure it is tight and not corroded. And here is what another owner did to correct similar troubles:

'I posted this under another topic but I'll repeat it here. Assuming the battery and charging system are ok, they one thing in common with this is the BCM. Before you go running to dealer to have this exspensive part replaced, I know of one person (elsewhere) that fixed very similar troubles by cleaning all the connections to BCM with product called 'DeOxit' (electrical connection cleaner) and ensured connections were tight. This person also did the same with all the fuses/relays in nearby fuse box. When cleaning around relay #23, they found what was possible arcing (short) to nearby ground plate and after cleaning that, he put a small strip of electrical tape over that area. He has not reprted any troubles since that I know of.' Good luck

buzzsaw007

I have a very interesting problem with my '97 escort. I was getting a scraping rotational noise (just noise, the response, feel, and function is all the same) when the clutch petal was depressed. I took it to three different mechanics, all of whom said it was likely the Throwout Bearing, and that the whole clutch may as well be replaced while they were in there. I got it replaced, then drove to Michigan for the holidays. Near the end of my return trip, the clutch started making the same noise (about 1000 miles later, almost all highway).

So in a nutshell, I replaced the clutch, and 1000 miles later, it started having the same problem.

What could cause a clutch to break? I'm thinking alignment, wheel bearings (I do get some front end vibration at high speeds), pilot bearings, bad CV joint... I don't know. Seems like something on the way to the wheel that's out of whack and stressing out the clutch. Does any of that sound plausible? Anyone else have any idea what could cause a clutch to go out, or do we think it was improperly installed?

What do you all think?

Thanks!

burdawg

In a nutshell, no. The alignment or balance of the front wheels won't have any effect on the clutch.
In my opinion, the clutch wasn't installed correctly, or the throw out bearing wasn't replaced or was replaced with an inferior part, or that wasn't the problem to start with.

idntnvu

My friend has a 1989 Chevy Beretta that he recently purchased. The turn signals worked when he got it, but now have stopped functioning. He checked the bulbs and fuses, all ok. Any suggestions?

Mr_Shiftright

Flasher unit (it's a relay actually).

rockynill

Just bought a 2001 Pontiac Sunfire. The digital odometer works just fine upon start up, but quickly displays an erratic readout consisting of somewhat faint numbers and dashes. If I bang on the instrument cluster, it will display correctly, but then quickly goes back to the erratic readout. Any solution to this problem?

user777

sounds like possibly a loose connection in a wiring harness or a flakey circuit board trace. the fact that you can bang on the thing, it works for a short period, then goes back to garbage... makes me think mechanically you have an intermittent connection somewhere.

i'd probably get a good strong flashlight and a big mirror and attempt to see if i can locate any wiring harness / connectors behind the assembly that look as though they are loose.

perhaps a pull-it place has a dash assembly you could look at to find the location of the connectors.

Mr_Shiftright

Yeah these things are very dicey. You might indeed try jiggling things around under there or pulling apart a coupler or connector (carefully) and cleaning it with some kind of electro-cleaner, but very often there's not much you can do with these kinds of circuitry. I suspect they make it very tough for anyone to tamper with the wiring for the odometer anyway.

user777

true, if it's a hairline fracture of a circuit board trace, or even a cold solder joint, there isn't much that an end user is going to be able to do to fix it, unless the whole assembly was removed, then the part associated with the odometer was identified, you get lucky, and so solder the fracture or the cold joint.

but, maybe by looking at one at a pull-it place, maybe the odometer is a module or a "daughter-board" or an LCD display which is connected to the main dashboard / motherboard with some sort of multi-conductor ribbon cable. if so, the problem could be one of the solder joints to the ribbon cable.

perhaps fiddling with the wires will be enough to remove mechanical stress that may be making the circuit intermittent.

shifty, i think you're right, they wouldn't want to make the ODO too easy to tamper with, but i suspect the display is on some standoffs or on the end of a ribbon cable, and the smarts and memory are on the main board. just a hunch.

cutlass1

I have a 1978 Cutlass Supreme 260 V8 2 barrel carburetor and HEI ignition system with 205,000 miles. This car has an intermittant starting problem when the car sits idle overnight and I try to do a cold start. The car will eventually start if I spray starting fluid into the carb and crank the engine. Sometimes I have to repeat that procedure a number of times before the engine starts. Once the car fires up, and the engine speed responds to the throttle, and I shut it down, it will start again on the first try for the rest of the day. On a couple of rare occasions, once the car starts and within the first 2 minutes of operation, the car will hesitate and lag and sounds like it is ready to stall. When that occured, I pulled over and let the engine run unloaded for a minute and after that it runs fine. Once the car is running, it accelerates smoothly and I am getting the same gas mileage as when the car was new.

I don't believe based on those symptoms that it is a fuel problem. I recently replaced the control module in the HEI thinking that might be the problem. I don't know what other components could fail that would cause an intermittant problem like I am having. Could it be a compression problem where when the car does fire up, oil goes into the cylinders and improves compression, thus making the car start for the rest of the day? Anybody have any ideas of what could make my car act this way? Thanks

imidazol97

Not an expert but did have a 1980 Cutlass with 260 V8 and the half quadrajet (front half, grin) that they used. If I recall there was a problem with the fuel leaking out of the bowl into the intake manifold (or outside the motor) leaving the bowl empty. It's not that hard to take off the top of the fuel bowl and see if the fuel level drops after sitting a long time.

I believe that could explain why the car runs poorly as the fuel sitting in the intake manifold is sucked in with the new fuel already rich for cold running from the choke...

It seems to me there was a problem with the plugs they put into the holes used to drill the main fuel passages. It seems to me they didn't quite seal and needed epoxied...

I may have my carburators mixed up from the 80s before fuel injection took over everything.

I assume you've checked the spark at a plug by laying it on the intake manifold and cranking cold. You also might have a float running low due to aging of the needle valve seal.

I'd do the cold check for fuel. If you don't want to take the bowl cover off (I don't recall the steps) you could let it sit a couple of days and then remove the air cleaner and push the throttle linkage to see if much gas sprays out into the throat of the carburetor. You should be able to drown the motor by repeatedly pushing the linkage. If it runs out of fuel after one or two pumps, that would tell you there's no fuel in the bowl to the proper depth.

Good luck.

ssulmtd

I have a 1996 Lumina with a 3.1 V6 and I have been wanting to hook-up my aftermarket gauges for quite some time now but I cannot locate where! I cannot even find the original oil pressure sending unit. I have even considered cutting into the heater hose to add a "T" so I can atleast get a water temp reading. I much rather place both sensors into the block. Can someone help me?

mpslick

Awhile ago I built a mild performance 350 C.I. chev S.B. I bought assembled World Products S.R. toquer cyl. heads. The engine ran flawlessly for 1000 plus miles. I then developed a serious miss and discovered a broken intake rocker arm stud and valve spring damper corresponding to that intake valve. The pushrod and roller tip rocker arm are fine. The valve spring looks good.
Has anyone seen this happen? Any ideas would be appreciated. Thanks MPSLICK

Mr_Shiftright

Could be a lot of things. If you are running a performance cam and high strenth valve springs with stock 3/8" studs, that might be the problem. I don't know if you can upgrade to 7/8".

Also I've read that the rocker arm trunnion should never rest in any area that was threaded.