OVERHEATING Can't Diagnose!!

[frank_castle]

well i was stuck in great miami traffic this morning when all of a sudden the temp started rising and the check engine temperature message came up on the status window. for like 2 days now ive noticed that there has been a little bit of coolant smell and after long traffic hours there has been a small leak "looks like its coming from the reservoir but i cant say that it might be also the hose on the bottom of the reservoir its just a pain in the arse to get to." so i have done some research online here but i still got a few quesstions. ohh and no matter what i replacing the thermostat its a 2000 lincoln ls v8 with 89,000 miles on it so for like $30 it seems like i might just replace for fun.

when the car starts up to when its actually past normal operating temp. "middle" there is absoutely no increase in fan speed on all my past cars there always has been also when u crank the A/C up to max there isnt any increase either. now i dont know if it might be a sensor that not engaging the pump or the fan "whatever" to open all the way and kick in the speed or if the thermostat has anything to do with that but im a mustang guy and this is the first car i have with all of the suffisticated electronics and i figured if it would be a sensor or electrical problem that the check engine light would come on.?..?right?..?

any help would be greatly appreciated im pretty sold on the fact that it might be the fan pump " anyone know about how much they cost" and im ready to change it but if its something else i rather give it up to the experts we have here online. thanks frank_castle

 

[LincolnTech38]

The resiviors crack all the time, if there is coolant under the car by the back of the drivers side wheel well, replace the tank.

00 V8 model year is also known for sticking thermostats, there was a recall on them. Also warped thermostat housings leaknig where it bolts to the engine block.

Does the fan operate at all? When the car is overheating it the fan should sound like an airplane jet engine.

 

[Quik LS]

+1

also check the deguass cap - the system need to keep 7psi and the caps have a common failure in them after taking them on and off a couple of times. If the cap can't hold enough of a seal, the system boils at a lower temperature than it should.

 

[frank_castle]

the fan does still work i just dont think its blowing no where near the amount that it should be even when i let the car heat up to about 3/4 on the gauge the fan was still spinning at the same speed then when it idles. also i dont know if it makes a difference but wit the A/C on max it also blows the same speed. so as of now im going to replace the cap, the thermostat, resevoir, and hoping that i dont need to replace the pump. thats why i wanted to know if there was a way of just checking the pump to see if thats what it is because its going to sux to have to pay $450.00 just for the pump and not be sure if thats what is broken.

 

[decibels5]

http://www.lincolnvscadillac.com/showthread.php?p=230738#post230738

 

[frank_castle]

ok after having a few beers yesterday to ease maybe having to make the purchase of the $400+ fan pump to the car i woke up early today to try to diagnose a little more and i noticied a few weird things. one the resvoir is cracked. 2 i noticed with my dad here thios morning i cranked her up and after like 5 min with the A/C on the fan finally decided to really kick on like it used to i mean like it used to u guys know the turbine noise. after the car got up to normal temp the fan the turned off. and never again did it turn back on even when it was starting to overheat again. what from the car tells the fan or the pump to engage, and can the cracked resevoir really have the system that messed up that it wont engage the fan " i didnt think they had anythiong to do with one another, i mean i figured once the temp was up the fan would engage no matter what right?..? thanks again leo

 

[Quik LS]

IIRC the fan should always be on if the AC is set to max.

There are two sensors for heating - one coolant temp and one cylinder head temp (CHT). I believe the 'temp' gauge is running off of the CHT - although the fan is controlled by the PCM, I do not know if it pull the sensor info from both sensors or only the coolant temp.

if you have a stuck thermostat - the coolant may be cold (I believe the sensor is on the driver's side of the rad) but the engine is hot....

 

[frank_castle]

well i went to the local lincoln dealer today and picked up new coolant reservoir (by the way hairline cracks like crazy), thermostat, and a cap. as of right now the car was idling for 45 without the a/c and 45 min with the a/c and nothing. it seems like everything is back to normal temp. i still need to take it for a spin and wait till friday morning traffic to really test it but as of now it looks like it might have been a mix between both the reservoir and the thermostat. i installed first the reservoir and left the thermostat untouched, cranked up the car and like in 10-15 min it was overheating again. the i let it cool down for like 3hrs went back outside and changed the thermostat. now the temp is back to normal i post up if there is any changes tomorrow. again like usual thanks to everyone who replied and threw there 2 cents in. thanks, frank_castle