what would cause my engine to overheat? is the coolant old? has the water pump failed? the pump was JUST replaced.

 

It could be any number of things. If related to the water pump replacement, it could possibly be an air pocket in the coolant system from improper filling of the coolant after the water pump replacement.

 

A restricted, partically blocked radiator ...

 

i'll top off the coolant. it started to spew out when i pulled over and the temp was in the red. if it still over heats i guess i'll have to replace the radiator.

 

well where was the coolant spewing out from? Like bob said, it can be a number of things. You might not even need to change the radiator. Figure out where the water come out from. It could be a hose, and it can be the radiator too. the water pump could've failed as well.

 

Check the thermostat.......even if it is new...they have been known to be bad right out of the box. Maybe its not opening up

 

the coolant was spewing from the overfill on the coolant tank cap. when i pulled out the cap/hose from the coolant tank, steam was coming out. when i put it back in the tank, it just bubbled out.

the water pump was just replaced.

 

last night i checked my service manual on how to replace the coolant fluid. i'd have to be a contortionist and have all of the proper tools and perhaps a lift in order to service this car myself.

i just came back from the dealership and i topped off the coolant level and drove it there. didn't overheat during that short trip.

i'm guessing the coolant was bunk. they said that they never replenished the fluid when they replaced the pump.

 

There are many reasons a car can overheat and without more details it's hard to narrow it down, but in any case, as long as you have enough of it in the cooling system, the condition of the coolant mixture, if any, is immaterial to your problem.

If every other part of the cooling system is fine, the car would be sufficiently cooled even if you had plain water in there.
Not that that is a good idea for the long run but the point is your problem lies elsewhere.

 

Also check that your cap is sealing properly , if your cap is old the rubber can get brittle and split or perish which means it won't seal properly and will boil .
Also check where the cap seals for the same reason .

 

Check the cheapest parts first, such as the thermostat and radiator cap. small cheap parts that are essential for proper system functions.

 

i think that there is a coolant leak into the combustion chamber. the coolant trickles down in capacity to the point that there is not enough coolant and the engine therfore overheats. the only theory for this coolant consumption is a bad gasket or perhaps even a cracked block. the exhaust has had a suspicious smell to it. the engine also knocks, which may mean that the coolant leak into the cylinder is giving combustion problems.

it's always one thing after another.

 

Do a used oil analysis to find out.

 

How do you do that? My car overheats everynow and then after about an hours drive or so. The coolant reservoir is always boiling, but my temp gauge stays still. Thermostat?

 

Order the test kit and send in a sample of your oil. They'll analyze it and report back metal content, fuel dilution, and collant percentage.

http://www.blackstone-labs.com/free_test_kit.html

I would do the simplest thing. get another radiator cap. It's not uncommon for a new cap to be defective. Then I'd look at thermo, but I'd do the oil analysis. Sounds like maybe a headgasket. check for any oil residue in the coolant.