10
votes
2answers
4k views

2005 Dodge Ram: easy way to diagnose code P0420?

My truck is reporting a code P0420, which apparently is "Catalyst System Efficiency Below Threshold (Bank 1)" which can either be the catalytic converter or the rear O2 sensor. The code came on at ...
8
votes
1answer
4k views

How much power (HP) do the components on the engine belt generally use?

In general, how much power (HP) to the components on the the engine belt actually use? I'm trying to come up with an estimate of how much horsepower an engine wastes on things like the AC compressor, ...
7
votes
3answers
16k views

Just HOW urgently should I replace this tire? Is it safe to drive on at all?

It's my rear right tire. It has a significant bulge in the sidewall. Here are two pictures of the bulge (original URL): Do I need to replace it before I ever drive on it again? Should I put on ...
7
votes
6answers
11k views

Does a strut tower bar have any useful effect on chassis stiffness for a car with 100K miles?

Aftermarket strut tower bars are generally considered to be decorative on many brand new cars. However, it seems to be a bit more logical that a chassis with 100K miles would have developed some flex ...
6
votes
2answers
194 views

How to know if I need new tires?

For the first time in my years of driving, I slid pretty badly the other day. I've slid before a little bit, but this is the first time I slid badly-- I nearly went off the road. Granted, it was ...
6
votes
1answer
719 views

Heater smells like sulfur

I drive a 2006 Toyota Sienna. When driving with the heater on I often smell sulfur. This is more common when I am driving up a hill, but if I turn the heater off, the smell goes away. What causes this ...
5
votes
3answers
29k views

Check Engine code P0420 Catalyst efficiency below threshold bank 1

After months of normal driving with no problems, my 2003 Honda Civic EX check engine light came on during a long trip. Got it scanned and it's P0420: Catalyst efficiency below threshold bank 1. They ...
4
votes
3answers
1k views

Ford Taurus common oil leak area?

On my last oil change, the technician noted some oil around top and side of the engine block and said there is a small leak. The only way to find where it is coming from is doing the whole dye test, ...
4
votes
2answers
3k views

Engine braking with an automatic transmission

For reference, I've reviewed these three questions: Manually shifting an automatic transmission? Does Downshifting (Engine Braking) Cause Extra Wear and Tear? Is engine braking harmful? I drive a ...
4
votes
3answers
6k views

How to know if timing belt failure will result in immediate engine damage?

I own two cars: a 2003 Acura TL and a 2005 Volvo S60. I've been told that depending on what car you drive, a failed timing belt can result in immediate engine damage. I would like to know (not just ...
4
votes
4answers
840 views

Does the tachometer provide any indication of fuel usage?

So, I'm driving along on the highway with the A/C blasting when I notice the price of gas. It makes me think, "what can I do to increase my fuel efficiency?" Some of the tips I've heard have included ...
3
votes
1answer
382 views

What is the best way to reverse engineer the signals of a CAN-BUS?

There are always better ways.... I'm up to reverse engineer some CAN-BUS signals. Before I start, I'd like to discuss with guys who done this before and are willing to share their methodology. I'm ...
3
votes
4answers
1k views

Does switching to neutral on an automatic transmission improve braking for immediate stopping?

I've been told that when needing to brake quickly, throwing the gear into neutral on an automatic transmission actually allows for better/quicker braking. I understand how things work pretty well but ...
3
votes
3answers
2k views

2006 Kia Sedona intermittently not starting

What could be causing my (non-)starting issues? Occasionally (once every two weeks or so) when the keys are inserted and turned to the start position, nothing happens. No noise, no dome lights dimming ...
3
votes
2answers
579 views

Occasional Vibration at specific highway speeds.

Symptom: At certain speeds (70 mph, 40 mph, etc.) there is a noticeable vibration. Vehicle: 1998 GMC Sonoma (2 wheel drive) The vehicle was purchased used and had similar symptoms at the time. ...
2
votes
1answer
78 views

Should replacing the brake pads make braking feel “softer”?

I've just had the brake pads replaced on my Skoda Fabia- apparently they'd worn very thin. But now when I brake I have to push down much harder on the brake pedal than before. Is this to be expected? ...
2
votes
1answer
1k views

Slow acceleration, high fuel consumption after spark plug change

I have a 2000 Ford Ranger 4.0 L V6 4x4 model. I recently was having some problems with the truck idling too low when cold and I decided to change the spark plugs. I put in 4 out of the 6 new plugs and ...
2
votes
3answers
293 views

Is my mechanic ripping me off?

My 2002 ford focus (built after may 23) died and the AAA and tow guy both said that it needs a new fuel pump. Anyway I went to the mechanic and he said it'll be 350 for the pump and 200 for labor. I ...
2
votes
2answers
2k views

turning right causing small vibration and noise

My 2004 Ford Focus makes small grinding and vibrating noises when turning to the right. The problem was much more severe earlier this month. I took it to the shop and had them get me new tires and an ...
2
votes
1answer
5k views

Check Engine Light on '94 Jeep Grand Cherokee

How do I get Check Engine Light codes (ODB-I) from a '94 Jeep Grand Cherokee, and where can I look them up?
1
vote
0answers
94 views

Fuel Consumption and other Fuel related data from basic OBD-II parameters

I want to know how can i obtain the values of Fuel Consumption, Fuel Economy and other fuel related information from basic OBD-II parameters like Vehicle Speed, RPM, TPS etc. I have noticed that not ...
1
vote
1answer
78 views

Volvos with the same parts as the Volvo 440 GL with 2 liter motor?

I have an old Volvo 440 GL (~1994) and I need to find a part to the exhaust system that costs the same amount as the car itself if bought from the Volvo company itself: this is the flange part in the ...
1
vote
2answers
908 views

How do I know if I need new brakes?

I recently purchased a car with 135k miles on it and I have no idea when the brakes were last replaced. I've done work on my cars before but never have changed the brakes, so I'm not sure how to tell ...
0
votes
0answers
32 views

Volvo 440 GL with 2 liter motor vibrating without gear, why? And how to diagnose this?

The Volvo is the Nordic model 440 GL, same as here. I have experienced this vibration earlier only in 1-2 gears with 1-2k rounds. Now I am able to experience it with no gear. My friends are suggesting ...
17
votes
6answers
117k views

what is the difference between DOT3 and DOT4 brake fluids?

What is the difference between DOT3 and DOT4 brake fluids? What could possibly go wrong if I use a (4 times cheaper) DOT3 brake fluid instead of the DOT4 which manufacturer recommends (but allows ...
12
votes
5answers
12k views

Is it safe to drive a car that has got a broken suspension spring?

Yesterday I was driving home from work and heard a loud noise which I can only really describe as a "clang". After looking at it today, it looks like the spring for the front left (passenger side) ...
10
votes
5answers
13k views

Does a timing chain need maintenance?

Does a timing chain (as opposed to timing belt) need any specific maintenance? In particular I'm talking about a BMW Z4
9
votes
2answers
2k views

What happens to a car when it hasn't been driven for 12 years?

I'm hoping that I'll soon be the owner of 2l turbo charged, 4wd hatchback that's been sat in a garage, undriven for over a decade. Trouble is that I won't be able to give it a full inspection until I ...
9
votes
3answers
7k views

How do I safely siphon gas from a tank?

Our 2003 Windstar was recently totaled in an accident (everybody's ok). This happened the day after we filled the tank. Before we hand over the car to the insurance, we'd like to get the fuel out of ...
9
votes
2answers
190 views

Proper Jack Location

In general, where is the best place to put a jack to prevent damage when lifting?
8
votes
1answer
779 views

How do I find the correct pins in a CAN-BUS connector?

This question might be too technical for this forum, but I'll give it a go. I have a 2012 BMW R1200R motorcycle with CAN-BUS. I'd like to make an Arduino interface to the connector on the bike, but I ...
8
votes
2answers
2k views

What are the possible causes of vibrating steering wheel?

What can be the cause of a vibrating steering wheel when driving faster than a specific velocity (let's said 60 mph). How to discriminate one cause from on other ?
8
votes
4answers
8k views

Why does a Turbocharger only produce boost when the engine is under load

As per the Title. Why does a turbocharged car only produce significant boost whilst the engine is under load. Is is something to do with how much exhaust is being produced or is there some kind of ...
8
votes
7answers
32k views

Is Prestone “All Makes/All Models” coolant *really* compatible with all models?

My car's manual says to use the blue Honda coolant: Always use Honda All Season Antifreeze/Coolant Type 2 [MSDS]. This coolant is pre-mixed with 50 percent antifreeze and 50 percent water. ...
8
votes
2answers
227 views

How to I stop the 'never-ending' turn signal?

I have an '07 Chevy Malibu, whose turn signal doesn't seem to disengage whenever I make a turn, unless it's more than roughly 160 degrees (a U-turn). What are some of the possible causes and are ...
8
votes
1answer
166 views

How to fix freezing locks

Does anyone know how to prevent locks on car doors from freezing, this is usually only a problem in older cars. I'm not thinking of solutions like WD-40 that really only work for a few days and then ...
7
votes
1answer
1k views

Must I Replace All 4 Tires on an All Wheel Drive (AWD) Subarau, when only 1 is damaged?

I have a 2005 Subaru Legacy 2.5i Wagon. I just destroyed the passenger-side rear tire. The tires have approx. 6/32" tread remaining, per an informal measurement with a coin (I used this guideline ...
7
votes
4answers
187 views

What clues are there to identify real mileage?

This is a bit theoretical question, maybe viable for a wiki. Suppose you want to buy a 10yo car and among available deals you see one with suspiciously low mileage (e.g. 5'000 km). Seller assures you ...
7
votes
2answers
6k views

Heater blows cold air at idle

I have 2006 VW beetle with the 2.5L engine. Once the engine has warmed to operating temperature, and I am driving it around, the heater works great. As soon as I stop at a red light, or am idling for ...
7
votes
1answer
9k views

Brakes make grinding noise during stops at low speeds

I've got a Mazda B2300 pickup that's started making a grinding sound whenever I come to a stop. Braking at a high speed doesn't make any noise, but once I get under 25-30 MPH, the grinding sound gets ...
7
votes
4answers
32k views

Cold start squeaking noise in engine

I just purchased a used 2010 Corolla 3 days ago. I've only now noticed that when I start the car, there is a squeaking sound coming from the engine. It lasts no more than a second. Sounds like it ...
7
votes
1answer
3k views

What are the tell tale signs of a catalytic converter that might be going bad?

I've owned two vehicles whose catalytic converters were recalled due two a couple of reasons: one being the quality of the CC and the other being a reduction in power due to a material building up and ...
6
votes
1answer
226 views

Is it normal for stop distance to be long on brand new brake pads?

I just had the brake pads replaced in my car. As I left the shop I noticed coming to a complete stop took longer distance or needed a fair bit more force on the pedal. Is this normal? Will the ...
6
votes
1answer
1k views

Engine revs up when braking

Background: 2012 Honda Civic EX, 5-speed automatic, with no mods except a non-stock tire (ran over a large bolt). I keep it maintained per the manufacturer's manual and always see the Honda dealership ...
6
votes
2answers
726 views

My car has multiple ODBII engine fault codes

2002 Nissan sentra se-r 2.5l Hope you can advice me on my car. My codes are: 0447, 1490, 0340, 0031, 0037 My symptoms: 1. Car stalls after driving for 5 minutes than cannot start for another 2 ...
6
votes
1answer
274 views

When should I change the oil, as the tech recommends or as my oil change light indicates

I have a Toyota Corolla 2008. It has an oil change light indicator. The tech at the one hour oil change place recommends to change it every 3,000 miles but the indicator light only goes off about ...
6
votes
1answer
1k views

Do newer cars actually monitor the quality of oil? [duplicate]

Possible Duplicate: How does the change oil light system work and does it matter what type of oil you use for it to work properly? Starting last August, I am currently leasing a BMW 328i ...
6
votes
5answers
6k views

Doing my own fuel induction service - how to, and how difficult?

Was recommended to get a fuel induction service for a 2002 V4 Camry, and am considering doing it MYSELF. The reasons for considering this are: My car idles a bit rough, especially when the AC is on. ...
6
votes
2answers
293 views

All weather tires vs winter tires on well-plowed roads

I live in Minnesota. I've seen lots of people recommend changing to winter tires in the winter. However, what doesn't make sense to me is that the roads are plowed very well here. 90% of my driving ...
6
votes
3answers
2k views

Troubleshooting 'random' clutch problems

I've got a customer who came in complaining that the clutch pedal had gone 'funny': it wasn't 'coming back up' like it used to. As he was in for service anyway, we replaced the clutch fluid, and it ...

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