Engine Heating Hi, I've observed that my engine is getting heated up pretty quick, just after driving 2 miles. I tried pouring water/coolant in the over-flow tank (looks good for 1-2 days, then same problem again), changed engine oil very recently, but still same problem. I see that theres some leak onto my alternator. Any guesses what the problem might be? I am afraid how much its gonna cost me!!! Its 113K driven '94 nissan maxima. Please help me.. Thanks

Suggests sign of internal leak. Check dipstick for engine oil to see if there is a sign of coolant mixed with engine oil. (Generally foaming of oil instead of amber or dark solid color) (Could even show level is high due to coolant adding to oil and raising level.)
If there is, it's a very serious problem.
One quick way to try a very inexpensive fix that's worked for me is a product called Barr's Leak. (It's worked twice for me on two cars.) Get the expensive "copper" version (looks like liquid copper) and add to your coolant system following manufacturer's instructions. Top off coolant and then drive car for a couple of full engine temperature sessions.
If coolant then no longer goes down, change engine oil draining out old coolant that may have contaminated it and refill with new filter.
Keep an eye on level after that to see if coolant level remains stable.
If coolant still goes down, a engine over haul or new engine may be needed.

Yes, the temperature gauge should normally stop in the middle, between the cold and hot points on the gauge. When the engine is cold the thermostat will be closed and will keep recirculating the coolant in the engine block until it warms up sufficiently. Then the temperature of the warm coolant will cause the thermostat to open the channel to the radiator to get rid of excess heat, which should stop the coolant from over heating. So the effect of the thermostat keeps the coolant at a fairly stable temperature. When the coolant runs low, it can't transfer enough heat to the radiator and the coolant and engine then over heats. Watch for radiator leaks under your car after you have been driving it. If the coolant goes low again fairly quickly you could have a leak in a hose or the radiator itself.

Check to see if the water is curculating. either by looking in the resivoir to see if water is coming out the return hose or by looking in the radiator, depending on your vehicle. If its circulating its not the water pump. If the car over heated majorly it could have cracked a head which would cause it to continue to over heat but first you have to find out what caused the over heating to begin with. Also you have to be careful what products you pour into your coolant system. most products that say they fix problems tend to cause problems in the long run. Some "fix it" products can clump up and clog small holes within the engine and in turn over heat it because the coolant can't flow properly. See if its circulating and we can go from there.

On a side note, if it is circulating, rev the engine to make sure it still circulates at higher rpm's. The water pump went out on my truck but would circulate when idling but not reving.

Well, i would have to say all of the above is a direct result of the water pouring out of the bottom. your coolant system must be full to function correctly, by the cylinders heating the coolant to keep them cool, and then the coolant is cooled back down in the radiator. you can damage the cylinders and more if you run it like that. look for exactly where the water comes out when you pour it in (try to contain any coolant. water alone would be fine to let run on the ground) my hunch is that you probably had a freeze plug come loose from the block, or blew a heater or radiator line. a freeze plug is the little 2" metal circle plate (or even block heater) pressed into the side of the engine under the exhaust on both sides. another possibility could be the water pump. this would be coming from the front side of the engine. there are also many other leak sources, but these are the most common. check the oil. if it is creamy, then there is coolant going into the engine. a freeze plug is an easy fix, as they sell rubber expansion plugs to plug the hole. you sinply stick it in and tighten the nut/screw as per directions and done. a blown hose is relatively simple to fix, but can also be complicated, depending where. most of the heater connections have o-ring and plastic clips that tend to be difficult at times to dis-assemble. a water pump would be expected to fail anywhere between 100k-150k miles typically, and is a cheap repair (i would expect 2-300 in my area)

The head has freeze plug(s) to prevent engine and head from cracking under extreme hot (over-heating) and cold (sub-zero temp).

When the coolant system over-heat,the hose and radiator are the 1st defense.

If the drive keep driving the freeze plug will give out to protect the engine block and head.

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Here are few pictures of freeze plus.

Link HERE

when the engine is cold, remove the coolant cap, start the car , put the heater on high and let it warm up (turn on the headlights to load the engine, speeds the process)-after about 10 minutes of idling, you should see the coolant start to move rather quickly, and if it has air in the system (like I think it does) it will 'drop' so that you might not see anything in the tank at all-fill it to the top, and replace the cap, drive it for a few miles observing the temp gauge.

Make sure the engine is cold!! There are only three areas for checking assuming that you have been running the car with sufficient coolant in the system 1) Coolant filler cap, This must have tight seal as it maintains the coolant under pressure when the engine is hot. Failure of the seal will result in no pressure build up in the subsequent loss of coolant by boiling off. 2) Check the thermostat, located within the metal housing immediately connected to the top hose of the radiator. Put the thermostat in a clear heat resistant jug and pour in boiling water. You should see that the thermostat should open immediately and remain open until the temperature drops below about 85C. If it does not, try a couple of more times to be sure and then buy a replacement. 3) Fan issues, If the viscous coupling at the back of the fan has gone the car will tend to overheat quickly when in slow traffic or even just idling. Conversely on the move the car will tend to remain cooler for longer as air is forced through the radiator matrix. A little trick to try in an emergency is to put the car heater to full heat with a full fan. Uncomfortable but the additional heat taken out of the engine cooling system can help prevent the engine overheating. The lack of viscous coupling can be felt by turning the fan blades. They should be sluggish even when cold and not spin after flicking over. If the fan does spin freely a new viscous coupling will need to be fitted. Engineers design cooling systems, thermostat, fan speed, radiator size etc. to cope with the anticipated heat output of the engine with surprisingly little margin; an overcooled engine is inefficient. Even a slight loss of effectiveness by just one component in the system can lead to overheating. Water pumps only cause over heating when the front seal fails and allows all the coolant water to drain out. This is obvious to see: loss of coolant from the reservoir and a brown stain running perpendicular to the front of the engine around the bay and hood innards corresponding to the line of the fan blades distributing the lost coolant

You might check the coolant level after the engine cools,if it's low add 50/50 mixture of coolant and water. Keep an eye on the level to see if it happens again. You might have a small leak in the system. Good luck

Sounds like coil is breaking down.Try pouring a little water around the base of the coil with car running if engine stops change coil.It could also be the ignition module heating up like the coil and breaking down.Engine analyser in workshop would very quickly pick up which of the two items is at fault.

Is the radiator or overfill jug loosing water over time? Even a small amount under the minimum can cause quicker heatups. Also, start the car and check your hoses. I've seen hoses collapse and cause problems similar to that.

The ambient temperature could also be a factor. When you're cooling the water and trying to keep it below 212; a breeze of 40 degree air is a lot better for the cooling then 90 degree air.

One other thing as well. Being as it is an older car, you may want to try blowing our the radiator. Using an air compressor with an air nozzle. Just blow air through the back (in the engine compartment) through the radiator and out the front. This will clean out the radiator from bugs, dirt, and debris.

Try those ideas and see how it turns out.