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I NEED HELP!
For the past few weeks my car has been overheating terribly. I recently replaced the thermostat and had a coolant flush. A day after I had these two things done I drove about 300 miles to see a friend. 60 miles from my destination, my car overheated almost into the red and proceeded to stay there or above the middle line the rest of the way. It also kicked my check engine light on. After ariving I went to autozone to see why the check engine light came on, it was the EGR valve. This confused me because i JUST had this replaced a month ago. Anyways, after having to drive under the speed limit I finally got home. I took it to the repair shop when I was back in town and they told me, after having my car for 6 hours, that I had a loose wire going to my fans. They tightened the wire and sent me on my way. Now, a day later, my car began to overheat 10 minutes into driving, and once again triggered my check engine light to come on. I need to know what is causing this. My car was sold to me as a lemon from the start, having to have a full engine replacement after 4 months of owning it. My thoughts are: waterpump, radiator, or enternal engine problem. I smell coolant most of the time when it overheats, but I never see a leak. Also, for a good month one of my belts squealed on start-up until warm if that has anything to do with it. Thank you to anyone that helps me solve this horrible mystery....  

first...

are you loosing coolant???????

if the system is low...     expensive engine damage will happen when you overheat the engine..

have you pressure tested the cooling system.....  it should hold pressure when tested...


does the electric radiator cooling fan actually work... there are two... one for the radiator cooling..   a second for the ac condenser..

the radiator fan is controlled by the engine control computer...  but it can also be turned on by the ac system when it needs more air flow to cool the condenser and the radiator..

the condenser fan is only controlled by the AC system.. here is the wiring diagram..  you will probably have to open it in a new window to view it properly..   you also did not mention if you have the four cylinder or the six cylinder engine..

 

i have a 4 cyl engine and  am not losing coolant that's the weird thing...
and i'm not sure if they checked the pressure or not when i went in yesterday. i've checked and my radiator cap is there as i have anti-freeze and coolant at correct levels.  

if you are leaking coolant..    its like when the pan on the stove boils the water out and the pan overheats and burns the food...  distorts the bottom of the pan..

the aluminum heads do not like to be overheated...  they expand beyond normal amounts and distort..  when they return to normal temp..  do to being distorted.. the clamping force on the head gasket may be reduced in some areas.. allowing compression and combustion gasses to leak into the cooling system...  this will over pressurize the cooling system and blow the coolant out..  causing a runaway overheating situation..


cooling systems are a thermodynamic balance...

the engine can heat up the coolant.. and the radiator and fans or ram air through the grill can cool it back down..

this reaches a steady state once the thermostat has cycled 2 or 3 times each start up..   but if you loose pressure.. loose coolant..  loose the cooling fans...  have blocked air flow through the radiator...  missing or broken thermostat.. blown head gaskets..  you remove some of the ability of the system to balance the temps... and to control the temps...

radiator pressure testers can be rented at many parts stores..
you will also have to rent the proper adaptor for the small cap that your hyundai uses...  

professional mechanics have advanced scan tools.. not the generic versions..   with those.. they can command the radiator and condenser cooling fans to come on for a circuit and operation test...  

i spoke with a mechanic but am taking it to a shop tomorrow, i am told it may be a blown head gasket? mind you, the dealership that sold me the lemon car was also the same dealership that put this used engine in to replace the old one that broke down. so them giving me a faulty engine does not surprise me.  

please... if they are going to change the head gasket..

specify that the head gasket gets installed with some hylomar applied to both sides of the head gasket then allowed to evaporate the solvents for 20 minutes prior to installation..



i have been using this since 1992.. and have not had to RE replace any head gaskets do to leaks since then..

its under 10 bucks at oreilly stores. and other stores.. its NOT the same as any other head gasket product.  and when installed.. you will see it pushed out from between the head and block along the edges of the gasket..

when i worked in a shop.. a honda with overheating problems came in..  another tech did the head gasket.. i told him and handed him a tube of hylomar with the instructions i gave you above..   a month later.. the same honda returned..  leaking again..  i looked at the edges of the head.. and saw no hylomar sticking out.. i ask if he had used it..  OF course..  where is the used tube.. that should have been enough for 3 heads..  he handed me an UNOPENED TUBE..  he then had to replace the head gasket again..

a few weeks later.. an aluminum camaro engine came back in with radiator fan failure..  it was steaming like a power generating plant..  the fans were replaced.. coolant added.. and there was NO leaking head gaskets..    i could not keep hylomar in my box any more.   he kept taking it to use on his jobs after that..  i had assembled it with hylomar..

oh.. the reason he did not use the hylomar.. he said the gaskets box said to use no sealer..  yea right.. sell more gaskets that way..  

second..

mechanics have the ability to verify the head gaskets are leaking in a way i came up with..

doing  a cylinder leak down test .. but using a compression tester hose with the valve core removed..

hooked directly to shop air..

a clear vinyl hose on the radiator cap adaptor from the radiator pressure tester..

each piston  set to TDC one at a time...

with the radiator totally filled and the clear vinyl hose looped over the hood latch..   any increase in coolant level ... will be easily seen in the clear hose as soon as the shop air is sent into the cylinder..

this does not work as well with a cylinder leak down tester.. as that has a fixed restriction in the hose...  with the valve core out of the compression tester hose.. you have full flow...

i use a remote starter button to position the engine for individual cylinders to be at TDC...

print this and take it with you to the mechanic..