Okay, I took my car on the road for the first time today after putting my engine back in to fix my oil leak. I'm glad to say I DID fix my oil leak, but now I have HUGE cooling issues. I was only driving my car for five minutes w/ the coolant temp steady. Then all of a sudden the temp gauge needle skyrocketed to the top and I immediately shut the car off. I let it set for a couple minutes to check my fan hook-ups and they looked good. So I start it up again and drive off and right away my temp went fricken high again. I ended up towing the car home because I couldn't even drive it the couple miles to my house. So long story short, I need your guys suggestions on what could be wrong. My fan worked fine before I pulled the engine but I don't know if the fan is the problem anymore.

Thank you very much for any help you guys can give me!

Matt

your fan can work fine, but you can still overheat.
lets start with the basics....

are you leaking any coolant?

are you positive you filled up your coolant tank to max and made sure it was at a good level?

stuck thermostat/ plugged heater core

Originally posted by madhatter210
stuck thermostat/ plugged heater core

I'd say heatercore but DON'T overlook these two.

Originally posted by Blizare

Originally posted by madhatter210 stuck thermostat/ plugged heater core

I'd say heatercore but DON'T overlook these two.

Okay guys, so how do I go about checking if the thermostat is stuck and the heatercore plugged?

Originally posted by 95venge

Originally posted by Blizare

Originally posted by madhatter210 stuck thermostat/ plugged heater core

I'd say heatercore but DON'T overlook these two.

Okay guys, so how do I go about checking if the thermostat is stuck and the heatercore plugged?

oh ya it can happen. just replace your thermostat and then take the heater hoses that come from the coolant pipes and make sure they are bent sideways or anything and make sure nothing got into them when you had your motor out for some reason, ie, mouse shit, stuff like that.

Originally posted by eclipse982nrRST

Originally posted by 95venge

Originally posted by Blizare

Originally posted by madhatter210 stuck thermostat/ plugged heater core

I'd say heatercore but DON'T overlook these two.

Okay guys, so how do I go about checking if the thermostat is stuck and the heatercore plugged?

oh ya it can happen. just replace your thermostat and then take the heater hoses that come from the coolant pipes and make sure they are bent sideways or anything and make sure nothing got into them when you had your motor out for some reason, ie, mouse shit, stuff like that.

Alright cool, do you think it would be a good idea to try buying a used thermostat from here or just go and buy a new one from the dealer? Oh and if the thermostat is the problem, would that cause the fan not to work either?

Originally posted by 95venge

Originally posted by eclipse982nrRST

Originally posted by 95venge

Originally posted by Blizare

Originally posted by madhatter210 stuck thermostat/ plugged heater core

I'd say heatercore but DON'T overlook these two.

Okay guys, so how do I go about checking if the thermostat is stuck and the heatercore plugged?

oh ya it can happen. just replace your thermostat and then take the heater hoses that come from the coolant pipes and make sure they are bent sideways or anything and make sure nothing got into them when you had your motor out for some reason, ie, mouse shit, stuff like that.

Alright cool, do you think it would be a good idea to try buying a used thermostat from here or just go and buy a new one from the dealer? Oh and if the thermostat is the problem, would that cause the fan not to work either?

dont go to the dealer, they will charge you too much. just to go autozone or whatever is by you, napa, advanced auto, whatever. they are like 15-20 bucks. i dont think the thermostat makes the fans quit working though. if your fans arent working, check the wiring harness for them and make sure the fuse didnt blow for some odd reason. the fuse for the fans is in the engine bay if i recal correctly. i would change the thermostat first, see if it happens again and then if it keeps up, check out the heater hoses.

if u dont know to change the thermostat, follow these steps.

drain coolant from radiator into a clean jug so you can reuse it since its fairly new.

remove upper radiator hose

remove radiator cap

remove hose coming from the overflow tank

unbolt the thermostat housing (2 12mm bolts i think)

remove that thermostat and put a new one in. (make sure you put it in the right way and not backeards!)

have fun!

Originally posted by 95venge

Originally posted by eclipse982nrRST

Originally posted by 95venge

Originally posted by Blizare

Originally posted by madhatter210 stuck thermostat/ plugged heater core

I'd say heatercore but DON'T overlook these two.

Okay guys, so how do I go about checking if the thermostat is stuck and the heatercore plugged?

oh ya it can happen. just replace your thermostat and then take the heater hoses that come from the coolant pipes and make sure they are bent sideways or anything and make sure nothing got into them when you had your motor out for some reason, ie, mouse shit, stuff like that.

Alright cool, do you think it would be a good idea to try buying a used thermostat from here or just go and buy a new one from the dealer? Oh and if the thermostat is the problem, would that cause the fan not to work either?

more than likely the temp sensor(check connections whatnot), also just buy a t-stat at auto zone for like 5 bucks get a 160 imo if your not in a heat needed alot area. A quick way to test it is to put it in boiling water, if it opens its good.And yes stuff happens when not in use. and side note ....this is a general question

Originally posted by madhatter210
stuck thermostat/ plugged heater core

You really think either of those situations could happen after taking out and replacing my engine? I don't know, but the cooling system was working fine before I did this.

Originally posted by eclipse982nrRST
your fan can work fine, but you can still overheat. lets start with the basics.... are you leaking any coolant? are you positive you filled up your coolant tank to max and made sure it was at a good level?

Yes sir, I'm sure there's no coolant leaks and I filled both the radiator and the resevoir tank.

Just spend 15 bucks on a thermostat and find out.

Easier than working on the heater core, thats for sure.

And also, a thermostat could just STOP working i guess. Do like hatter said and test it in the boiling water first. :shrug

Originally posted by Blizare
Just spend 15 bucks on a thermostat and find out. Easier than working on the heater core, thats for sure. And also, a thermostat could just STOP working i guess. Do like hatter said and test it in the boiling water first. :shrug

in case all else fails and it isn't what was mentioned , you can isolate the heater core till you get time/money to fix it. Cut both lines and get a plastic splice for rubber hose connections and loop it. hint: also a good way to test the heatercore. But they give signs as to when there bad in general. you smell anti-freeze when the heat is on and may also see it on the floor. But it could get plugged like eclipse92'r69'r said (bees nest mice ect ect)I'm thinking more than likely a connection for the temp sensor or something like that. ? is it bubbling into the overflow when it heats up?

Originally posted by madhatter210
like eclipse92'r69'r

wtf? lol

Originally posted by eclipse982nrRST

Originally posted by madhatter210 like eclipse92'r69'r

wtf? lol

Dude, no one can remember your long ass name. For real. Like how everyone calls me Miller or Amiller, they can't remember the numbers and shit.

You guys ever think it could just be his thermometer giving his gauge a weird reading? If you're driving along and your gauge suddenly spikes really high I'd say that thermometer sensor is fucked up. Not the coolant temp sensor, the thermometer above it.

Hey guys you're awesome, I really appreciate your guys' help! So yeah I'll get a thermostat tomorrow and see if that takes care of it. Oh and madhatter, I don't think the coolant bubbles in the reserve tank when it heats up either. Anyway, thanks again fellas!

Matt

Woah woah. Didn't you say you have a fan issue? If I were you I would check a couple of things before you buy something. First start the car in the drive way and let it idle until it gets up to normal temp. Do the fans come on? If not there is your issue. If they do come on and operate fine then you can start looking for other issues. There are 3 things I'm thinking, coolant sensor for the guage (the one wire sensor on the coolant neck), thermostat, or you still have air bubbles in your coolant. Just filling the resivior is not always enough. To get all the air out start the car and then carefully remove the cap while the car is still cold. let it circulate (this will tell you if the stat is opening) and make sure all the air gets out, then replace the cap. A lot of things can go wrong when you pull an engine, things stick together, get overlooked, or improperly sealed. It's the nature of the beast, but I would try to diagnose the issue before you start replacing stuff. Now if these other guy's have more knowledge into your issue than this post then you may not need to diagnose it, but I always check before I buy if I can. It could be something as simple as a bad radiator cap leaking pressure...

Originally posted by Kirby
To get all the air out start the car and then carefully remove the cap while the car is still cold. let it circulate (this will tell you if the stat is opening) and make sure all the air gets out, then replace the cap.

I think it floods over before the t-stat opens at 190.I guess the easiest way to check .....turn the heat on.

You might just have an air pocket in the cooling system. In my experience sometimes it will over head or boil over the first time you start it up then the air will work its way out of the system. Usually you just have to add more coolent after this and it will be fine.

Originally posted by madhatter210

Originally posted by Kirby To get all the air out start the car and then carefully remove the cap while the car is still cold. let it circulate (this will tell you if the stat is opening) and make sure all the air gets out, then replace the cap.

I think it floods over before the t-stat opens at 190.I guess the easiest way to check .....turn the heat on.

It does stream through the little hole on the stat, but you can tell the difference when that stops and the stat opens up. When it shoots through the hole it is preassurized and you can tell cause it does spatter a bit, then when the stat opens up it smooths out and you can see the flow and there is no more spatter..

Okay guys here's an update. I put a new thermostat in today, refilled the radiator w/ coolant, and relieved the cooling system of any air bubbles. I let it idle for 7-10 minutes. Now in this time, according to my stock water temp gauge the temperature kept rising and rising. I finally shut the car off after around 7 minutes because the temp gauge was reading 3/4 of the way up. And the fan didn't turn on either. So do you think it could be one of the two coolant sensors are bad. Both of their connections look good.

Any help appreciated!

Matt

Have we totally ruled out a water pump?

Brian

It sounds to me like this is a guage sensor issue. Your car will not get that hot in 7 min. There are 2 sensors on the coolant neck. You need to replace the top one with 1 wire. If you have a datalogger check to see the acctual coolant temp at idle. But I am guessing that you don't have one.

Welp, I found out my car isn't overheating today. I ran the car at idle and measured the coolant temperature w/ a meat thermometer. It's obvious my gauge isn't reading correctly because it was reading at the top when the car only got to 110 degrees. But that's the hottest it ever got. And my fan came on at this temperature too. And of course the thermostat never opened either because it didn't get hot enough. So I know my temp gauge sensor is bad, but would that cause the fan to come on so early too? Or do I have another problem there to fix?

Thanks for the help!
Matt

The fan will come on based on the reading of the temp sensor. If the temp sensor thinks it's a billion degrees, then yes, it'll come on.

Alright then, I'll get a new sensor and hopefully take care of this problem. And do you think it'd be okay if I drove my car until I get the sensor? I mean when it was running last night there was black smoke out the exhaust from it running rich because the engine runs cold, but would it hurt to drive it like that?
Thanks

Matt

The only issue you have is that the guage sensor (the single wire sensor) is not reading right. If you can access a data logger to check what the ECU sees that would be ideal, but the Coolant temp sensor for the ECU is pretty cheap so you could also just replace it, it's up to you brother..

Ok I finally got my car running right again after replacing the thermostat housing and gauge sender (thanks to 1995talon) and the coolant temp sensor. No I don't have a datalogger but I used the meat thermometer again to measure the coolant temp. Everything seems good now. I'm wondering though if it's normal for the fan to kick on around 140 degrees like mine did. Eh, probably just paranoia. Anyway, thanks fellas for helping me out w/ this.

Matt

Well shit, just when I think I fixed my cooling problem, I get kicked in the balls by something else! :wallbash You can see by my previous post that everything seemed to be working fine earlier. So I drive up town and the fricken gauge goes crazy again. Is it possible for a different USED temp gauge sender to be bad too? And now I'm leaking coolant like a son of a bitch. When I shut the car off, coolant was leaking out in a steady stream in the area at the back of the engine bay in line w/ the back of the flex pipe. Is this a bad heater core/hose? What the hell is going on here? Do all my problems boil down to one thing? And what would be some signs of overheating if I really am overheating? Sorry about all the questions, I just really need some help right now!

Thank You

Matt

fix the heater core hose, get it all buttoned back up, let the air come out, top it off, all the good stuff then see if it overheats again

if your loosing coolant it will overheat pretty quickly. IMO fix the leak then worry about the temp sender