hey all, I have a 2000 elantra with 66000 miles, it starts and runs fine for about 10 to 15 min. then it overheats, smoke/steam come in from the heater vents but there is no moisture on the floor or anywhere inside , local mech says its the head gasket, I am thinking maybe the heater core, what do you think......

 

Smoke and steam may be coming in the vents from under the hood through the hood vents. Could be head gasket since it's overheated. Might be warped head by now. Another possiblility is the water pump is bad, or hoses are leaking. Get a second opinion, I'm sure the mechanic wants to charge big bucks to do the head gasket.

 

are we talking vapor/steam from the cabin vents, or the cowl area??

what does the temp guage read??
what is the coolant level??
any smoke out of the tailpipe?? (how much, what color)
does it run rough when the smoke appears??

this could be multiple problems, and depending on what the answers are to the above questions will determine the next suggestion/recommendation i volunteer because your description goes three different directions.

what you *could* have is a leaking heater core that you ignored until it no longer had enough coolant to seep out into the cabin (the wrong way to 'fix' a leak), which in turn caused the coolant level to diminish to the point it could no longer provide ample cooling to the engine, causing the head gasket to break, creating extreme temperatures to rise within the cooling system which turn the remaining coolant into steam (which will rise, as steam does) which then follows the cooling system hoses to the heater core where the first hole (that was sorta fixed but not quite right) allows the steam to escape through the vents alerting you to the newest malfunction to your prized, well maintained (only??) vehicle. (no extra charge for the sarcasm, but please, this is the *only* way i have ever seen anything like this ever happen)

since it's a 2000, w66k, i figure this thing doesn't see a lot of road, which most likely meant it didn't get a whole lot of maintenance to the cooling system since it sat around a long time. look at the bright side. the timing belt was due 3 years ago (5 yrs/60k), so you're up a bit in that catagory. just make sure a new belt is installed when the headgasket is replaced.

NOTE:
this diagnosis may be changed at any time depending upon the responses to the above questions, additional input on symptoms, and whether or not i have cab sauv or chiraz in my glass tonight...

df

 

Look at your dip stick and see if the oil has a white milkey look to it. If so you blew the head gasket. From what you described id say you have a blown headgasket, cause well not enough infor to tell ya. but thats my guess

 

temp. is normal at a standstill but will go up once car is in motion, if I stop it will go back to normal slowly, coolant level is just a little low only about a quart or two to refill , no smoke at all from exaust, dosent run rough at all it actually runs smooth even when the temp is up, and I did check the oil its clean no bubbles, no milky appearance at all, also, upper hose will get hot but lower hose stays cold, changed the thermostat but still have the same problems, thinking it could be the water pump now....

 

[align=left]Water pumps don't ususally fail to pump water unless the belt is loose, the seals in them fail and they leak. Water pump is driven by an outer accessory belt. Make sure this is tight.

 

Certainly not a head gasket issue. Besides the oil issue, the engine would never cool down once it had over heated. Check the belt on your water pump, but I think your radiator is corroded to the point it is mostly plugged. I would take the car to a shop that specializes in radiator repairs. They can do a flow test on it and determine if it is bad or not. Unfortunately with modern aluminum radiators, it will likely need to be replaced if it is plugged.