Ok so here goes, this may be a lengthy post, but im at whits end with this car.

We bought it for 500 bux, 1999 Concorde with 2.7 DOHC, guy said it was just running hot and there was no cabin heat. SO we took a gamble on it, (keep in mind we had no real idea that the 2.7 motor was so crappy, never owned one or worked on one before this car) and drove it home, all seemed well except the fans werent running, but it was a cool day and all highway driving so it didnt get really too bad hot.

So we get it home, and do the dumb stuff first, coolant temp sensor, hardwire the fans to see if they run, check all the fuses, relays, blah blah.

So the next day, we fire it up, and let it warm up, and this god awefull metal to metal sound emerges from the engine, most notably from right under the valve covers, and thats when this storm started.

We took off the valve covers and upper plenum, and i plug around a little, then grab the timing chain on the right side head, just to wiggle it around and see if its maybe slapping around against something, and it moves OFF the pully just by hand.

So we tear it down, 2 guides are broke, the chain is stretched and has jumped time by 2 teeth, and the tensioner is frozen up.

We go to autozone, spend 400 bux on the complete timing kit, and a water pump, cause theres no way im gonna go this deep into an engine and not replace it. We put it all back together, line up all the timing marks, free spin the engine by hand to make sure nothing binds up, and then button up the front of the motor and reassemble.

Oh i forgot to mention, someone shoved a 1/4 of a shop towel into the upper radiator hose assembly, and was basically blocking water to one of the heads, i dont know if it was intentional or accidental. But we removed it all.

We buttoned up the motor, reinstalled everything, changed the oil, flushed cooling system, and prayed to the gods when we turned the key.

It started after just a few cranks, no engine codes, no leaks, and the motor sounded FANTASTIC.

so we drove it to autozone, of all places right, heheehe, and had a computer diagnostic ran on it just to be sure, and no codes came up.

On the way back, sure as the sky is blue, i started smelling antifreeze, and my heart dropped into my chest. Its overheating, STILL.

To recap, replaced coolant temp senser, replaced ENTIRE timing system, water pump, few gaskets and other stuff.

We are down to the heater core, and thermostat, which is being replaced now as i speak, the thermostat that is.

Upon feeling both lines to the heater core when engine was HOT, both the heater core lines were cold, and the car has no heat from the heater whent he water is CLEARLY boiling.

Any thoughts or suggestions on this?? any help is appreciated

 

did u bleed out the air in the system?

 

As far as i can tell its bled, it says in the manual theres supposed to be a bleeder with a nipple on it for a hose , but whats in mine is just a brass bolt, so i just loosened it and let air escape

it does take a little while for the car warm up when its cold, i mean its not like an instant overheat, but sure enuff as soon as the temp guage reads about 1/4 of the way, where it should run normally, theres water boiling back in the overflow, both core hoses are nowhere near hot, and the fans wont kick on unless i pull a relay after i start it

 

on another note, i forgot to mention how GOOD this engine runs. It purrs like a brand new motor. no pings, no rattles, no noise at all since we replaced the water pump and timing assembly

i really really

no trace of water in the oil
no smell of exhaust from the cooling system
no visable leaks of any kind

only think like i said i havent changed is the thermostat and heater core

ive checked all fuses relays plugs, and everything to do with the fans, but they refuse to start unless i pull out a relay for the HI/LOW and wait a few secs they will start and run all the time

 

a heater core wont make u over heat.
will it only over heat while driving or can u ull over and it cools off?

 

Does the same thing wether driving or sitting and idling, about 10 mins after cold start, engine warms up to 3rd mark on temp gauge, maybe one higher, then starts overflowing boiled coolant into overflow, fans will only start if i pull out hi/low relay while its running then put it back in, but fans will run until its shut off that way


were gonna change the thermostat this morning and see what results that brings, and backflush the heater core, and fish the lines for blockage


will post results this afternoon

 

Sometimes idiots put the thermostat in backwards in these. If it is in backwards I hope whoever is doing it doesn't put it back in the same way.

 

We changed the thermostat today and put it all back together, heat gauge climbed up to just under half, the way it should, and it hit half way mark one time, fans turned on like clockwork, and it cooled down to under 1/4 of the way and never did go back up to half


im getting just a little overflow, but it didnt do it long, it was mostly air expelled and then it stopped and car ran like a champ


no heat still in cabin, and both hoses leading to heater core are cold, even after an hour drive.

we flushed every line possible with garden hose, even the heater core, nothing is blocked

im completely stumped, it seems to have a SLIGHT overheating problem now, and still no cabin heat, im at the end of my roap here

replaced water pump, thermostat, timing assembly, coolant temp sensor, and flushed everything

motor has NO signs whatsoever of blown headgasket, no water in oil, no funny smelling oil, no exhaust smell coming from radiator, no white smoke upon start, holding hand to tail pipe comes back completely clean with no smell

help!

 

u have a clog somewhere there

 

Im going through the same thing with my 1997 concorde lx. I have been reading many similar threads for the last few days. several people have had the same problem and never have solved it after replacing everything possible. Im hoping it is solveable! Good Luck and I will keep posting any new info I find.