The "Ask a Mechanic" Thread

[Bubble Screen]

One of the few times.

I didn't get any help...:kickcan:

[SloppyOneXXVI]

Thanks SS, appreciate the help.

[SkinnedAussie]

Another Q

when my car is stopped and running (like at a red light) every once in a while I feel a subtle lurch in the car. What's up with that?

If your car has an automatic transmission, it might be worth getting it serviced.

[SkinnedAussie]

I didn't get any help...:kickcan:

It's a bit difficult when we don't get all the facts, AND we don't have the vehicle in front of us to be able to carry out a full diagnostic check.

Those of us trying to help are only doing so by way of the info you give us.

'Hyuk, I gots me a truck that won't start. What's wrong?' Where do we start?

The more info we get, the better advise we can give. It also helps if it is your own vehicle, not someone else's who mentions the fault to you, then you post it here.

Friend to you - 'I clipped a kurb last night and it flattened a tire and bent the rim. When I got going again, I noticed a vibration from the front, and it was pulling to the left. What's wrong with my car?'

What gets posted - 'Steering wheel is not centred. What could be wrong?'.

See my point?

[Prosperity]

Does it feel like it skips a beat for a moment or does it feel like the car is lunging forward?

doesn't go forward it just rumbles (not audibly, but I can feel it) for half a second then goes back to what it was doing.

it's a 2003 Mitsubishi Galant (automatic)

[dfbovey]

I have a 2006 Toyota Rav4 v6 and have had to replace 2 coils in the span of the last year and a half.

Any idea what would cause coils to fail so frequently? I'm worried that the other 4 will wait to go bad until after my warranty is up.

[twa]

I have a 2006 Toyota Rav4 v6 and have had to replace 2 coils in the span of the last year and a half.

Any idea what would cause coils to fail so frequently? I'm worried that the other 4 will wait to go bad until after my warranty is up.

I'm lazy

http://autorepair.about.com/library/faqs/bl059i.htm

[dfbovey]

I'm lazy

http://autorepair.about.com/library/faqs/bl059i.htm

Thanks!

You'd figure if this is a common problem in Toyotas, that they'd also try to fix the problem causing the failures instead of just replacing the coils when they go bad. Especially with all the bad pub they've been getting.

Thought I was buying a reliable car. But I've had more problems with this car than any other I've owned.

[Bubble Screen]

It's a bit difficult when we don't get all the facts, AND we don't have the vehicle in front of us to be able to carry out a full diagnostic check.

Those of us trying to help are only doing so by way of the info you give us.

'Hyuk, I gots me a truck that won't start. What's wrong?' Where do we start?

The more info we get, the better advise we can give. It also helps if it is your own vehicle, not someone else's who mentions the fault to you, then you post it here.

Friend to you - 'I clipped a kurb last night and it flattened a tire and bent the rim. When I got going again, I noticed a vibration from the front, and it was pulling to the left. What's wrong with my car?'

What gets posted - 'Steering wheel is not centred. What could be wrong?'.

See my point?

Dude, I was sorta joking.:pfft:

And yeah, my problem wasn't easy to dissect, given what information I gave. Its all taken care of now, though. No worries.

[Leonard Washington]

doesn't go forward it just rumbles (not audibly, but I can feel it) for half a second then goes back to what it was doing.

it's a 2003 Mitsubishi Galant (automatic)

AC or cooling fan engaging? In my old car, either of those two coming on would cause a slight increase in RPM.

[Prosperity]

Most likely some sort of ignition misfire.

Does it feel like it skips a beat for a moment or does it feel like the car is lunging forward?

Also, what kind of car was it again?

service engine light came on, and it was a cylinder misfire

same thing happened last year. I got my spark plugs replaced, and the light went away and I haven't had any problems, but now it seems like the same problem has come up. Could it be the sparkplugs (again?) or could it be the wires.

also, will my car blow up or something if I continue to run it for the next few days? I have to travel about 200 miles this weekend.

Edited May 13, 2010 by Prosperity

[Springfield]

I have a 2006 Toyota Rav4 v6 and have had to replace 2 coils in the span of the last year and a half.

Any idea what would cause coils to fail so frequently? I'm worried that the other 4 will wait to go bad until after my warranty is up.

If I'm not mistaken, that car has a coil-over-plug set up. Basically meaning that each spark plug has one ignition coil that drives it. There aren't any ignition wires, except for a small rubber boot, connecting the coil to the spark plug. There isn't a distributor or anything of that nature.

The coil-over-plug set up is very common among most new cars. The automakers do this because it allows for a stronger spark and greater control over the timing of the spark. Both of those things lead to greater efficiency which improves both fuel economy and engine performance.

Now, I would assume that you've had two different ignition coils fail recently. For instance, cylinder #1 and cylinder #3 ignition coils. This happens all the time (it's very, very common on Mazda V6 engines and Fords of all models). Typically if one ignition coil has failed, the others aren't too far behind. I would fully expect that you have several more ignition coil failures ahead of you.

The best way to fix the problem is to replace all the ignition coils and all of the spark plugs at the same time. It's outrageously expensive though, meaning most people will opt to only replace the failed ignition coil.

I always give a customer a "disclaimer" if they choose to replace just the failed ignition coil. Kind of a "Spend $1200 today or spend $1200 over the next several months or year." type of thing. It's all up to the customer because, in the end, it's their money (and time).

Hope that helps clear some things up.

[Springfield]

service engine light came on, and it was a cylinder misfire

same thing happened last year. I got my spark plugs replaced, and the light went away and I haven't had any problems, but now it seems like the same problem has come up. Could it be the sparkplugs (again?) or could it be the wires.

also, will my car blow up or something if I continue to run it for the next few days? I have to travel about 200 miles this weekend.

I'd suspect the ignition wires or (coincidentally) an ignition coil.

No, I wouldn't recommend driving with a misfire. It could cause further engine damage if not attended to in the near future. It's up to you, but I wouldn't drive any further than I had to if my car was misfiring.

[.Guy.]

I have a quick question about my 2004 VW Jetta GL 2.0L. So the generator light (looks just like a battery) came on about a week go and just yesterday the car really started to falter. Stereo would shut off on its own and putting the windows up or down would cause the car to stutter and nearly stall. I replaced the battery today with a quality Optima one (overkill most likely) and that fixed the power issue but the warning light is still on. I've been doing some research and it sounds like it could be the alternator, belt or even a faulty fuse.

The car isn't having any issues with power right now... but if it is a bad alternator I would expect this new battery to die pretty soon. Any ideas on what it could be?

Awesome thread BTW. Appreciate you guys helping us non mechanically inclined folks out.

Edited May 15, 2010 by .Guy.

[twa]

yep sounds like the alternator

loose belt will make the light come on intermittently

Edited May 15, 2010 by twa

[.Guy.]

thanks. I am taking the car to Advanced Auto Parts today since they can check it out for free. I took a closer look as well today and it looks like all the connections are secure. The belt also looks good so every thing is pointing to the alternator. Kind of weird for it to go out after only 35k miles. Maybe its because for 3 years I had a pretty loud system in the car.

[DCsportsfan53]

I have a quick question about my 2004 VW Jetta GL 2.0L. So the generator light (looks just like a battery) came on about a week go and just yesterday the car really started to falter. Stereo would shut off on its own and putting the windows up or down would cause the car to stutter and nearly stall. I replaced the battery today with a quality Optima one (overkill most likely) and that fixed the power issue but the warning light is still on. I've been doing some research and it sounds like it could be the alternator, belt or even a faulty fuse.

The car isn't having any issues with power right now... but if it is a bad alternator I would expect this new battery to die pretty soon. Any ideas on what it could be?

Awesome thread BTW. Appreciate you guys helping us non mechanically inclined folks out.

Before you replace the alternator, check the fuse box on top of the battery. They have a habit of shorting in two places, the alternator harness (far left cable, black one with a flat fuse) and the 30 amp fuse for the coolant fans. Solid chance when you open that car you'll immediately see that the cable and fuse box are melted. If that's the case, you'll be replacing the fuse box and alternator harness first.

[.Guy.]

Before you replace the alternator, check the fuse box on top of the battery. They have a habit of shorting in two places, the alternator harness (far left cable, black one with a flat fuse) and the 30 amp fuse for the coolant fans. Solid chance when you open that car you'll immediately see that the cable and fuse box are melted. If that's the case, you'll be replacing the fuse box and alternator harness first.

thanks for the advice. Turns it out was indeed a bad alternator. Got it checked at AAZ so I am pretty sure. The fuse box looks fine and so do the cables. Now I just need to find a place that can do the repair for cheap. I would try it myself but I'm in Richmond (VCU) and no tools or even a garage here.

[21cents]

i got in a accident

my front bumper came out little bit. The bumper has scratches and stuff but nothing major. and my hood has a little dent.

If i get someone from craigslist to do it. What kind of money should i expect to pay? (dont wanna get ripped off)

[Veretax]

Well I got my car's oil changed, and new front brakes put on, and a question came up.

Is it normal when you put new brakes on for the feel of the pedal to be a bit different? (Like I noticed the brakes would slow the car with little pressure, but if I needed to stop faster the pedal has to go to the floor) I assume some of that is normal given the pads were near their end of life expectancy.

[Springfield]

i got in a accident

my front bumper came out little bit. The bumper has scratches and stuff but nothing major. and my hood has a little dent.

If i get someone from craigslist to do it. What kind of money should i expect to pay? (dont wanna get ripped off)

I have no idea to be honest. The body repair industry is completely different to be honest. The body repair industry can be shady though so I have a could of pieces of advice. #1: If it seems too good to be true it probably is. #2: Do not pay for the repairs until they are done! I've heard plenty of stories of people getting ripped off by scams.

Well I got my car's oil changed, and new front brakes put on, and a question came up.

Is it normal when you put new brakes on for the feel of the pedal to be a bit different? (Like I noticed the brakes would slow the car with little pressure, but if I needed to stop faster the pedal has to go to the floor) I assume some of that is normal given the pads were near their end of life expectancy.

So with the old brakes the pedal would go to the floor? With the new brakes it's a lot more tight?

If so, that is normal.

[Veretax]

So with the old brakes the pedal would go to the floor? With the new brakes it's a lot more tight?

If so, that is normal.

No. The breaks slow the car as soon as you apply pressure, but they don't really do so quickly unless i push the pedal almost to the floor (this after the new pads were put on). Before I hardly had to use little if any additional pressure at all to get the brakes to do that.

[twa]

No. The breaks slow the car as soon as you apply pressure, but they don't really do so quickly unless i push the pedal almost to the floor (this after the new pads were put on). Before I hardly had to use little if any additional pressure at all to get the brakes to do that.

Sounds like they need air bled out or adjusted

Or of course the master cylinder going out

Do they feel spongy when pressure is applied

[JustAfan47]

Sounds like they need air bled out or adjusted

Or of course the master cylinder going out

Do they feel spongy when pressure is applied

I agree with you that most likely the entire brake system should be bled front and back. I have seen in some cases that the rubber part of the brake line wears down and causes the small rubber portion to balloon just a little bit there for reducing they hydraulic pressure in the system. No ballooning effect with soft pressure on pedal(low psi in brake system). Hard pressure on pedal(higher psi in brake system) rubber portion in brake line balloons just a little enough to not allow max pressure builded up for caliper to push pad firmly enough on disk rotor. I've seen this before just not a lot.

[HoustonSkin]

I was driving on the highway one day and my dash lights were randomly coming on and going off and my tachometer and temperature gauge needles were dropping and coming back on. I thought it was the alternator, so I took it to a alternator place who tested the battery and alternator. The alternator was good, but the battery had a couple bad cells, so I replaced it. The guy also suggested that I replace the battery ground cable, which I did. Now my dash warning lights, etc just stay on when the car is on. From what I've read online, this seems to be related to a loose or improper ground. The car seems to start and run fine. Anyone got any ideas?