Alright, ill try to say everything that is happening.

One thing is that every once in a while my temp gauge goes all the way up and makes my car say to check engine temp then if I speed up or slow down or sometimes do nothing it just goes right back to normal. It happens almost everyday.

Also almost everytime I turn the car on all the lights on the dash stay on like the brake light and check engine and stuff but if I turn the car off and back on its fine and dash is like normal.

Another thing is that when I turn the heat on it takes longer than it used to to heat up . Then it will get cold and back hot randomly

I don't know if any of this is related. Just trying to figure this stuff out. Any help will be appreciated

By the way it is a 2005 mercury sable ohv

I've seen bcm's go bad they can make cars do some crazy shit on random

Havent gotten any air in the coolant system have you?

 

 

 

 

 

edit: check this out

 

Edited October 20, 201410 yr by garychurch84

Sounds like some kind of weird fan clutch issue with it heating up and cooling so often.

Did you check the headlight fluid? Maybe the canuter valve?

lol

The heating/temp issue that you're experiencing sounds like a possible air lock in the coolant system and possible a sticky thermostat.

As for the dash lights... Good luck.

Did you check the headlight fluid? Maybe the canuter valve?

Why did you take the time to type this?

The heating/temp issue that you're experiencing sounds like a possible air lock in the coolant system and possible a sticky thermostat.

As for the dash lights... Good luck.

I was thinking some kind of thermostats. Figured that's what was messing with the engine temp. Gauge because I know its not getting hot but the gauge keeps saying it is

I'm not sure about the light thing, but the heating/cooling issue is screaming faulty thermostat or a problem with the radiator fan(s). How are you sure that the engine is not running hot even though the temp gauge says it is high?

I'm not sure about the light thing, but the heating/cooling issue is screaming faulty thermostat or a problem with the radiator fan(s). How are you sure that the engine is not running hot even though the temp gauge says it is high?

I guess I'm not 100% but iv had cars over heat and know how they would usually do and smell and stuff. . And the gauge just goes all the way up in a split second and go back down the same way. So I wouldn't think a motor can heat that much and back down that quick. . And it has happened pretty much right when I start the car for the first time in a day but then sometimes it wont happen at all durring a day

Ok, what you say makes sense. Sounds like a wire issue somewhere. Maybe bass has caused wires to rub raw somewhere? I had a caged Tacoma and the vibration of the tire tread and extra rigid chassis caused a wire to rub through to metal behind my dash and my cluster did some weird things and then just popped the fuse. Very different circumstances, but maybe the same problem.

 

I'm not sure about the light thing, but the heating/cooling issue is screaming faulty thermostat or a problem with the radiator fan(s). How are you sure that the engine is not running hot even though the temp gauge says it is high?

I guess I'm not 100% but iv had cars over heat and know how they would usually do and smell and stuff. . And the gauge just goes all the way up in a split second and go back down the same way. So I wouldn't think a motor can heat that much and back down that quick. . And it has happened pretty much right when I start the car for the first time in a day but then sometimes it wont happen at all durring a day

 

Then its not the thermostat either if it does it sometimes when you first start the car...I'm still leaning toward some faulty electronics

Yea there is a really good amount of flex from the system in the car so I guess that could be it. Should I just start taking apart the dash and checking wires?

my wifes pacifica did the exact same things your describing and it was the pcm.

Yeah...... This is absolutely 100% for sure something to do with your PCM.

You said it happens every day? Did it start after a few days of constant rain?

Get it checked at a parts shop, they should be able to run a diagnostic. I have been through your situation so many times with my last vehicle.

Yeah...... This is absolutely 100% for sure something to do with your PCM.

You said it happens every day? Did it start after a few days of constant rain?

Get it checked at a parts shop, they should be able to run a diagnostic. I have been through your situation so many times with my last vehicle.

Where would they be able to test it? Should I just get an ecu from a junk yard and try it out?

Yeah...... This is absolutely 100% for sure something to do with your PCM.

You said it happens every day? Did it start after a few days of constant rain?

Get it checked at a parts shop, they should be able to run a diagnostic. I have been through your situation so many times with my last vehicle.

Where would they be able to test it? Should I just get an ecu from a junk yard and try it out?

Here in NC Autozone will hook it up and check it for free. Pretty sure most auto parts stores are doing that nowadays in the hopes that you'll go right back in the store and buy whatever it turns out to be. Call a parts store local to you and ask if they run a free diagnostic check.

That.

Find the temp sensor and check the ohms value to verify its functioning.

Second would be check the temp sensor circuit for grounding or out of spec resistance.

I would take it to a garage that has a certified mechanic to get it checked out. Most places like autozone just have a code reader.

 

Also do you get a check engine light coming on also?

Edited October 23, 201410 yr by pmureika

Did you get this fixed? Curious of what it was.