How Much Does It Cost To Replace A Heater Core For A 2009 Nissan Versa

What does it mean if there's oil in my radiator?

Means you have a leak between the oil system and the cooling system. Probably means you also have coolant antifreeze in your oil... check the dipstick for water contamination. That's a worse problem.This is bad and is a sign that the walls between the coolant and lubrication system have corroded through (from depleted coolant - too old) or your engine block is cracked from freezing or severe overheating.  Both oil and coolant travel through passageways in the block and the walls between them can be thin.  Another possibility is a head gasket failure.This is not a totally uncommon ocurrence I have heard, and to fix Head gasket is not too bad but the corrosion or cracked block will likely be expensive. Continuing to drive this way will eventually destroy the engine totally (it's not that far from there now, even though it may be running). The watery oil will foam and be ineffective. the metal parts will rust and eventually the engine will seize as the hole gets bigger and the leak worse.

What does it mean when the engine is seized?

Engine seizure is normally the result of a failure of the lubrication system. It is often where a piston has friction welded itself to the cylinder bore. Sometimes it will be the big end bearing , the main bearings or the small end bearing. The net result is the same, though. The engine cannot be rotated. If you are very lucky, and the siezure is only slight, then the engine may free up again when it cools down. But damage will still have been done. Until water cooling and special oils were developed, racing two stroke engines were notorious for piston siezures.

What could be wrong with a Nissan Altima that cranks but wont start?

The fuel pump fuse is blown or the fuel pump has failed.The crank position sensor has failed. Turn the key to "Run"Listen for the fuel pump to run for a few seconds then stop.If you don't hear the pump run:1) Turn the ignition key to the "Off" position and remove. Check the fuse in the engine bay fuse panel. This is a panel encased in a plastic box and usually has "FUSES" printed on the cover. Inside are high draw, high amperage fuses and relays for things like the fuel pump. Find the pump fuse, pull it and look to see if it's good. If it's blown, replace it with same amp rating fuse. Check again to see if you hear the pump run. If it does, you're lucky. Press on. Car should start. If the pump still doesn't run then see 2 below.2) If the fuse is good, then it's a good chance the pump has failed. You will have to tow the vehicle to the shop; it's dead in the water.If you hear the pump run and the car cranks but will not start, chances are it is the Crank Position Sensor (CPS). The CPS feeds info to the engine management computer telling it the crankshaft is rotating and to allow fuel flow and ignition to occur. If the computer doesn't get the CPS input, the car will not start. Again, dead in the water and a tow to the shop.Just had this experience on my '98 GMC pickup ...good pump, engine spins, no start. A flat bed ride to the local shop and ...ta-da! ...OBDII code reads CPS malfunction. Four hundred and some odd bucks later, she's up and running like a top.

What problems go along with a bad catalytic converter?

A clogged catalytic convertor causes the symptoms of a loss of power when accelerating or going up a hill. This is an often overlooked cause of loss of power, can cause check engine fault codes and lights, and mechanics will often change a few parts unnecessarily , especially if it is only partially plugged. A couple ways I check for plugged cats when a low power complaint is a symptom, and other obvious basic maintenance items have been checked for service is to have someone hold the rpm at about 1800 to 2000 steady. Then check for a good push of exhaust with my hand from behind the tailpipe. A plugged or partially plugged cat typically leaves a hot sickly feeling exhaust flow from the tailpipe. Compare to a known good working car nearby, known to be performing properly and with the same amount of cylinders. That slow , hot sickly flow at 2000 rpm compared to the hard push blowing your hand away of a not clogged cat is a dead giveaway, and I have NEVER misdiagnosed a plugged cat , or made false diagnosis with this method. Another way is watching a vacuum gauge connected to the intake manifold. When revving up, if the exhaust is plugged the gauge reading will climb then begin to slowly drop as the exhaust pressure builds up. Further testing will be needed to verify which part of the exhaust is plugged. Diagnostic by codes is unreliable and until now I had not heard of it. A code p420 only refers to catalyst efficiency. And can be set by faulty o2 sensors. Removing the exhaust and testing for engine power returning to normal works. But the hot sickly flow has been most accurate with my experience, in several cases where shops had missed it, were stumped and called me to come check. They are always embarrassed for missing the simplicity, but need not, as cars and their complicated electronics and even age old problems can lead to loss of power without any immediately obvious cause.

Can a clogged catalytic converter unclog itself?

Well, it can happen that they will de-clog on their own, but usually need a helping hand.  If it is utterly blocked, then dismantling and manually cleaning is the only solution.If the ceramic material inside is melted, then change it.Most modern Cats are stuffed with a ceramic honeycomb structure, unlike the older ones that had complex filters with platinum wool amongst other stuff inside them.One of the reasons they get clogged is people lugging around in fifth gear making lots of soot which clogs the honeycomb.A faulty EGR valve (gas recirculation) will do the trick as well.Faulty injection, allowing to much fuel to come through the exhaust can cause the honeycomb to melt when it starts burning the fuel... (replacement)But you can clear a blocked (not 100% blocked) converter by getting it hot enough to make it finish what it is supposed to do.The garages here in France have a naughty technique, they hoist the car up on lift with the motor going flat out, and stand underneath it holding a fire extuinguisher, just in case it sets fire to the car, or any flames from the now burning soot comes blasting out of the rear.It is a dangerous technique in my opinion, and not good for the engine, but it works.  I don't suppose it works everytime either.So if you have a CAT that is partially blocked because you mooch around in fifth gear or have bad driving habits, you could try driving the vehicle hard enough to heat the CAT as it should be, where usually it can clear itself.So , if it is soot build up, there is hope for you, to unclog it without taking it off the vehicle and or changing it, if it is hard blocked with mineral deposits, unlikely. If it is melted, its got to be changed.

How long can I drive my car with bad coil packs?

It is not a question of how long you can do it. It is more a question if you should.The answer is you should not. You can drive the car until it breaks down completely (and it will). While doing so you will, as pointed out by other answers, run the risk of damaging the converter but you also run the risk of fire.If the coil is faulty very bad things can happen. Car fires are usually related to causes associated with fuel, and/or electrical. Once a fuel part starts leaking while a car is running, a fuel drip can be the formula for fire if you get sparks from a spark plug wire or an ignition coil that is faulty. Something like this could be the end result. (the image is from the web, I am just using it to illustrate a possible scenario, I do not know what happened with the beamer) But I have seen a Lancia catch fire from a faulty ignition coil.So, why risk it? Yes, they are not cheap, but you really should get a new one. By trying to "save" a few bucks you may end up having to spend a lot more.

I overfilled my car's engine with engine oil, can that harm my engine?

I felt obligated to answer this because I saw many answers I did not agree with. Being ASE certified in the category of engine repair and engine performance, I can tell you why overfilling your car with oil is very bad and can damage the bearings in the engine. The rule of thumb is not to fill more than 1/2 quart over the specified capacity.As we know with Pascal’s law, a liquid cannot be compressed, but it can be pressurized. Your oil pump pressurizes the oil to be sent to various places inside the engine; this pressurized oil is squirted through small holes in the bearings where the crankshaft and camshafts ride on oil pressure and do not make direct contact with your bearings. This greatly reduces friction and the load is supported solely by the pressure of the moving fluid. This is why each car has a recommended oil weight and viscosity by the vehicle's manufacturer based on bearing clearance.If your oil is filled up enough to where the crankshaft can dip into the oil it will cause aeration in the oil. This turns the oil into a foam with pockets of air and as we all know a gas CAN be compressed. This aerated oil goes into your oil pump and the oil pump compresses the air effectively reducing oil pressure in the engine. This can lead to main bearing damage, rod bearing damage, cylinder wall scoring, camshaft journal damage to name a few and can lead to catastrophic engine failure, in a worst case scenario.Most vehicles have an oil dipstick, on the dipstick you will notice a minimum and a maximum fill range. The distance between these marks is usually one quart of oil. You can tell how much your vehicle is overfilled based on this distance.Edit: I wanted to thank you all for the views and upvotes but also I wanted to add some more information.On the 2nd generation Prius, if the engine oil is overfilled by more than a half quart, the PCV system will suck the excess oil through the throttle body and stall the engine. We have seen some come back on a flatbed after quick lube changed the oil. Once you drain the oil a little the engine will be able to run again.