How long does it take to repair a head gasket?
You don’t repair a head gasket, you replace it.Once I had a rally car - a bit of a ratty old junker if the truth be told - that had a 2.3 litre overhead cam engine. It was a bit like this, only this one is way nicer:Anyway I was heading off to do a rally on some Friday night. On the Thursday, the day before, I took it out for a blast around the lanes to shake down any last-minute faults, and blew the head gasket. It was too late to do anything about it that night, so next morning, I got up at the crack of dawn, stripped the engine down to the point of having the head off (it was OHC, so that involved also removing the cambox, timing belts, etc. plus the exhaust manifold, inlet manifold and carburettors) By then it was almost 9am, so I drove to the nearest big town - 25 miles away - to get a replacement head gasket set. 25 miles back, and by 10am had the head all cleaned and ready to be reassembled. Engine back together and running by 12pm, I then had to drive it 250 miles to where the rally started. It all went smoothly and I made it with plenty of time to spare.So the answer to your question, for me, on that occasion, for this car, was about 6 hours, including an hour to fetch the parts. Sometimes what you need, apart from the basic skills, which in my case don’t amount to all that much, is a great big incentive!As I recall, the rally ended in disaster, but that’s another story.
What does it mean if a spark plug turns black?
the engine is too rich. either the main jet dropped, its badly tuned, or the choke is stuck on. this gives a dark, dry, sooty, almost crumbly deposit.the engine is using oil. also visible due to the plume of blue smoke from the exhaust, and the plug will be black and oily. wet looking.the plug is of the incorrect heat range. the heat of a plug has nothing to do with combustion temperature, as long as the mixture is correct, its always basically the same temperature. no, the heat range is how hot a plug gets during operation. a hot plug “holds” heat in and gets hot, and this heat is what burns the carbon off. the ideal plug will remain white or turn slightly tan coloured. (a bit darker in the case of two strokes).a cold plug will run cooler.a hot plug suits a low speed engine under low load operating at low speeds. think your lawnmower… an air cooled industrial engine.a cold plug suits an engine that runs hot. think a DOHC liquid cooled car run at full throttle.a hot plug in a hot engine will fail due to overheating. a cold plug in a cold engine will quickly foul and fail, due to carbon.never bother cleaning plugs. if they are turning black with no mechanical reasons, such as carb tuning, get a new plug with a lower heat range.
I have mazda 323f it is blowing too much smoke from exhaust what could be the reason???
Depends on what color the smoke is. A heavy white cloud witha sweetish smell could be antifreeze. Blue smoke is generally oil. Smells a little like fresh paved asphalt. Remember also that if you live in the north and it is cold you will see more exhaust smoke than normal. You may want to have a professional check it out to be on the safe side.
What causes black smoke in petrol cars?
Black smoke in the exhaust of petrol (gasoline) powered cars is caused by incomplete combustion of hydrocarbon fuel resulting in black carbon particles. Incomplete combustion is mainly caused by too much fuel for the amount of air available, or by fouled fuel injectors that don’t properly atomize the fuel. Too much fuel is caused by faults in the fuel injection control system that includes fuel pressure regulators, air volume and temperature sensors, and the engine control computer.
What is wrong with the build quality of American cars, why the bad rap?
I’m basing this answer on what I have observed and read over a lifetime of car watching.John Z. Delorean wrote that no automotive engineer at GM was encouraged to make an improvement which could not be seen as an improvement. Engineering in the seventies was a wing of marketing; innovation was not an end in itself.I believe that “the Big Three” North American auto makers have allowed the easy profits of luxury models and pickup trucks, abetted by low fuel prices, to interfere with the Darwinian progression of automotive technology in the rest of the world.My mechanic/friend worked at the time for a GM dealership in a nearby city. He also maintained my Toyota 4Runner from the time it was new until I sold it at 370,000 km. He did a brake job at 231,000 km. He shouted up to me: “Did you ever use these brakes?” He explained that he was seeing new GM pickups coming in for brake jobs at 50,000 km. But the worst thing was the habit of cylinder sleeves on the V8’s coming loose and sliding down until they caught a ring on a piston. I marvelled that something like that would get past quality control testing.At work his bread and butter was engine swaps on minivans. He could do one in 12 hours. He also started repairing the automatic transmissions on the vans. It seemed as though nobody else knew how to do the job, so they were just taken out and replaced, with the owner paying the cost.But I’m not convinced that any of the import cars are better. My friend changed the timing belt on my son’s used Honda Civic. A week later the crankshaft broke. There was a casting fault which weakened the crank to the point that the torquing of the end bolt to specifications was more than it could handle. Of course nobody rebuilds a Honda engine. There is such a flood of JDM engines, surplus from Japan, that there is no point.But I have to come back to my ’95 4Runner. That was a well made, if bone simple, machine. I had to keep the valves adjusted, but for the rest it worked very well for a long time, on road and off.My parents owned Chrysler products from a 1966 Chrysler (great car) to a series of increasingly mediocre vehicles. Finally I suggested they buy a used Honda CRV so that they wouldn’t be getting their Dodge Dakota stuck all of the time. To my surprise, they did. Instant contentment. They loved the thing’s quality and utility.
Will driving with a oil leak in the valve cover gasket hurt the engine? If so, how can this be prevented?
Is it an oil leak or an oil seep? Does oil run down the side of the engine leaving a clean trail as oil drips on the ground? Or does it just form a nasty, mucky oil-dirt combination that slowly builds?If it's actually a leak, get it fixed now. You can lose sufficient oil to starve the engine and cause premature wear or even failure. On top of that, you have an oil slick being left wherever you go, oil is probably dripping on the exhaust causing nasty fumes (not to mention a potential fire hazard) and you are having to spend money on oil that is just going to hit the ground. Not to mention it's not exactly good for those plants by your driveway to have oil washing into them.If it's a seep, don't ignore it. Get it fixed. If you have to wait a week or 2 for financial reasons, that's understandable, but don't push it out too far as it can develop into a leak. In addition, the dirt, cottonwood fluff, dandelion seeds, etc that can get stuck in the slime will do a few detrimental things. For one, it insulates your engine raising operating temperature a bit. Most cars engine oil relies on the side of the block and the oil pan to radiate heat away. Remember, oil functions as a lubricant, cleaner, and coolant! If the block and pan are caked over in grime, it is harder for the oil to transfer it's heat through the pan and into the air. This grime can also pose a serious fire hazard. Not fun.
What are some things to replace when a car hesitates at low rpms?
First off figure out and diagnose why its doing that, or else you wont have a clue what it is or else youre going to just be throwing parts at it and money down the drain by just simply guessing. From my experience its not one cut and dry answer It could be lots of things. Most likely if it has a carburetor the carburetor needs an adjustment, or spark plugs are old and worn out, air filter is possibly worn out and clogged with debris so its restricting the airflow. Oxygen sensor is a possibility. Or it could be a fuel filter/injector clogged/ fuel pump blocking proper fuel flow. The catalytic converter or exhaust could be clogged up with carbon deposits, but i doubt that. Lastly if its really high mileage like 200,000–400,000 miles and it could just simply be old and worn out and the piston rings arent sealing very well, so its low on compression which will make most engines low on power but thats pretty unlikely especially if youve taken good care of it, done oil changes on time and its maintained. All these items are consumables, they are regular car maintenance repairs. Its amazing how much better a car will run when you replace all those things and wear out over time. Take it to a reputable ase certified mechanic or if the car is under warranty go to the dealer. Or if you got a buddy thats good with cars take it to him. The good news is its usually something simple, and all those things arent hard to fix unless its the fuel filter/fuel pump. tell me how it goes. Good luck dude!
What are the symptoms of a burnt exhaust valve?
The symptom you’re likely to notice the most when you have a burnt exhaust valve is a loss of power from the engine and an increase of fuel consumption as the engine is run harder to do the work expected of it. Other symptoms will be dependent upon how badly burn the valve is. You’ll be looking at a valve job to correct it, or else swap out the cylinder head altogether.When the edges of an exhaust valve burn, the combustion chamber no longer seals and not only do you lose compression in that cylinder, unburnt hydrocarbons will be exiting before they can be ignited.Running an engine low on oil will often burn one or more valves before the main bearings start to pound. Otherwise, a lean fuel mixture can cause this, too.On modern vehicles with a full exhaust system, the sound can be hard to discern. However, a cylinder leakage test will pinpoint it fairly well. Your pressure loss will be fairly high and you’ll hear the pressurized air escaping through the exhaust system, rather than through the intake or the crankcase. If you hook up a vacuum gauge, you may notice a steady loss of vacuum at idle if a valve is burnt or sticking.