taufiq

I agree with @adil on this one. Finding, and fixing a power drain can be very tricky, and this is best left to a competent garage. However, this can sometimes be very expensive, so my advice would be to have the battery checked out first. A simple current draw test will almost always identify a defective battery in only a few seconds, and this test is a whole lot cheaper than trying to find a power drain. My guess would be that the battery is not holding its charge, and there could be many causes for this. Even a marginally overcharging alternator can damage a battery over a long period, so I suggest you have the alternator tested as well, before it damages the new battery as well. Also don't forget to check battery cables and terminals, as well as ground cables and connections for proper contact. A bad ground connection can easily cause the symptoms you describe, so check, and double check all connections. Also check all the connections if you have any aftermarket accessories fitted, such as lights, and sound systems. It often happens that defects in aftermarket accessories damage both batteries and alternators, so be sure to check out all accessories if you have any.

Hi Hamd, The garage guy was right when he said that Elantras have bad transmissions, but I seriously doubt that they are replacing at least one transmission per day. There are three main problems with Elantra transmissions: 1.) Speed sensors inside the transmission often fail for no apparent reason. This is relatively easy and cheap to fix, but I suggest you take it to the dealer to have this done. 2.) You don't mention if the "ESC" warning light comes on when the car starts jerking. This is a common problem, and it happens because the stability control system is trying to limit the torque output. The stabilty control system works with the transmission to limit torque to the driving wheels when it mistakenly "thinks" there is a dangerous situation that could cause you to lose control of the vehicle. There are many reasons why the stability control system could fail, but the best thing to do is to have a comprehensive OBD II (diagnostic) check performed to eliminate (or confirm) the stability control system as the cause of the problem. Independent garages often do not have the software (or knowledge) to run a full diagnostic check, so rather take the car to a dealer for this. 3.) Hyundai transmissions have the ability to "learn" the driving style of a driver. This is called "adaptive learning", and it often happens that the system gets confused, or loses some of its memory. It is posible to reset this feature, but only dealers should be trusted with this. There is is no single cause for the adaptive learning getting confused, but possible causes are known to be battery replacements, flat batteries, or sometimes voltage spikes in the electrical system that could have dozens of causes by itself. Transmission fluid replacement do not usually fix the problem you are having, but my advice would be not to replace the transmission before you have had the points I listed checked out. All of them are cheaper than a replacement, and besides, you could have the same problem with the new transmission as well. I hope this helps, and please keep us posted on what you find, since it could help other members with the same problem.

Hi kasim, When you change oil, the new oil turns black almost immediately because not all of the old oil drains out of the engine. Some old oil sticks to the inside of the engine, and some remains behind in the oil pump, crankshaft, and other engine components. This old oil mixes with the new, turning it dark in colour. This is not a problem, and it does not effect the new oil in meaningful ways. Oil turns black because it mixes with combustion products such as carbon and others, but the additives in the oil protect the metal parts of the engine against these combustion products. Changing oil before it is due for a change is therefore just wasting money. Modern oil is designed to provide proper lubrication over the entire oil change interval time prescribed by the manufacturer of your car, so don't worry about the oil being black or dark in colour. This happens to all oil in all engines, and it is nothing to worry about. However, there are a few things you can check about your oil. If the engine has overheated for instance, the oil will have a "burnt" smell. If it has this smell, the additives that protect against friction have broken down because of the high heat. In this case, the oil does not provide enough lubrication, and you must change it. Another thing to check is if the oil drips off the end of the dipstick. If it does, the oil is fine, and you don't have to worry. If it does not drip off, and a drop of oil hangs off the end of the dipstick when the engine is warm, the oil is too thick, and it must be changed. This usually happens when you have been topping off the oil level with different brands of oil, or if the crankcase ventilation system does not work properly. It is always a bad idea to mix different oil brands, because they are seldom compatible, which makes the oil thick and difficult to pump around the engine. The engine ventilation is controlled by valve that can become clogged, so have this checked out when you have your car serviced next time. I hope this helps.

Hi Joyce, Sonatas have a known problem with interior lighting, but you don't mention your specific model. Earlier Sonatas have a setting on the map lights that says either "Map", or "Door". If your car has this setting, set it to "Door", and check the lights again. If this does not work, check fuse #20 under the dashboard. This fuse controls some of the interior lighting, and more often than not, this fuse is blown. You can also check fuse #19, which controls other interior lighting, the radio, the clock, and some other items. If the fuses are fine, there is a break in the wiring between the fuse and the dome light, or between the main fuse that supplies power to the fuse under the dashboard (#20). The door switches that trigger the dome light are not known to go bad, and in most cases, the fault is related to bad wiring that causes fuses to blow. Sometimes these wiring problems can cause bulbs to burn out very quickly as well, so check the bulb to see if it is OK. Replacing the bulb does however not solve the problem, and there are unfortunately no reliable work-around solutions. There is also no easy way to check these circuits/wiring yourself, since you have to remove trim panels, the roof liner and other items, so I suggest you leave this to a competent mechanic.

Hi VijeshRedronic, A quick question- how do these flushing machines remove all of the engine flush liquid from the engine? How can the operator be sure that there is none remaining in the oil pump, crankshaft, camshaft(s), or in the variable valve timing mechanism?

Hi taqir, Unfortunately, there is no such thing as a "life-time" oil fill for any transmission, no matter what the manufacturer says. Transmission fluid is no different from any other liquid lubricant, in the sense that it is a base oil to which several different types of additives are added to reduce friction, corrosion, and the formation of sludge. However, transmission fluid is not affected by oxidation as much engine oil is, but over time, the additives in transmission fluid will break down due to the effects of heat and contact with oxygen. Nevertheless, high ambient temperatures, the effects of towing, and engine overheating are very difficult to quantify, so manufacturers base their claims of a "lifetime" oil fill for their transmissions on the supposition that the car will never be used for towing trailers and/or boats, that the engine will never overheat, and that the car will not be used in areas where it gets very hot. But this is only one half of the story. The other half involves the fact that modern transmisions are several times more complex than they were just ten years ago, so the reason why manufacturers do not provide dipsticks to check fluid levels is to prevent unskilled persons form tampering with the fluid level on the one hand, and to prevent people from adding the wrong fluid to a transmission, on the other hand. Most modern transmissions will only work with fluids that have been specifically designed for that specific transmission, and while most transmission fluids are red in colour, the wrong formulation can destroy a transmission. So, from a marketing perspective, it sounds great when a manufacturer says that the fluid never needs replacing, but from a practical standpoint, the transmission fluid cannot last forever. An added problem is that the amount of fluid some transmissions need are never published, so if you take the bull by the horns, and decide to replace the fluid in your transmission yourself, you don't know how much fluid will fill the transmission. Too much fluid is as bad as too little, so if you are experiencing trouble with a transmission that has a "lifetime" fill, the only place that can replace the fluid is the dealer, since you will often find that the transmission fluid for your car is only available from the dealer. My advice would be not to deal with independent transmission shops when you have problem with a transmission on which you cannot check, and adjust the level of the fluid yourself. Independents do not have the equipment to even check the fluid level, much less the diagnostic software to check for electronic causes of shifting problems. If your vehicle is still covered by a warranty, hold the dealer to his responsibility to fix all and any problems that you might have with the transmission. Lastly, transmissions that have "lifetime" fills have no set fluid replacement intervals, but if you do a lot of towing, I would suggest you have the fluid replaced at the dealer at least once every two years. Towing raises the temperature of transmission fluid significantly, which causes the premature breakdown of the additives in the fluid. I hope this helps, but if you have further questions or concerns, let me know.