Hey guys, i have my coolant reservoir filled to the line when car is off, no leaks. fans are functional...i get in the car after it sits there overnight and drive about 2 minutes in maybe 70 degree weather and it jumps from the middle up past the H til it cant go anymore....i pop open the hood its relatively normal temp in there. same as it used to be before this started happening. so i bought a thermostat with gasket and changed it myself and refilled the tiny bit i spilled pulling the hose off....i drive for maybe a mile and it is up above the H again....any suggestions? before i changed the thermostat i had a coolant leak behind my intake manifold. one of the hoses broke and i replaced it and flushed the coolant and replaced it....maybe a week later all this started....i heard, what sounded like, fluid sloshing around in the big hose on the top passenger side of the radiator....could it have been boiling i heard? even though it looked a normal greenish color when i changed the thermostat?

thanks for the help....car sat for over 30 hours so far and not one leak when i cheked it out today, and fluids seems to all be good...

 

Hmmmm, coolant temp sensor?

 

1. You might have air in the lines (since you said it happened right after you flushed the coolant).
2. Change the radiator cap.
3. There are two seperate sensors that detect coolant temperature. One is the ECTS (Engine Coolant Temperature Sensor) and one is the guage sending unit. Perhaps that sensor took a crap. Both sensors are located in the upper radiator hose to the right of the front valve cover. (I think this is not likely to be your problem).
4. In a car I previously owed, my temp gauge itself went bad and would intermittently swing instantly from "normal" to "overheated"... not what's happening in your case, but something else to keep in mind.

 

probably not, the Engine Coolant Temp sensor is for the ECU, the Sensor right next to the ECTS is the sensor used by the temp gauge, so replace the sensor in your upper radiator hose.

 

how do you know it's the sensor that is his problem? I understand making a suggestion, but outright stating that he has to replace the sensor is

 

HA I meant its not going to be the ECTS but he could be on the right track still with the sensors. AND I wrote this with out seeing your msg.


That was based on the fact that he said his needle shoots up and when he actually checks the engine bay its not that hot..

Could also be that his radiator is blocked in the middle so not flowing, replace your radiator !!!

 

thanks for the help guys, the radiator is 5 months old, the exact name of this sensor in my upper passenger side hose is called what exactly? and is it 10 bucks, 100 bucks? 1,000 bucks? just a general price for it....also is this dealer specific or autozone pick up? thanks i hope this will do it, i'll wait a bit til late afternoon to swing by dealership for more responses, thanks...i heard like a gurgling, sloshing, sound in that exact area....is that a sign of it going bad? heard this that time i was leaking coolant and was overheating like mad on the way home.....

regardless, plase let me know the name of this sensor and if its something i need to be saving up hundreds for, lol thanks....

 

The ECTS cost me $NZD50 so probably for you about $US20 .. i'd IMAGINE the other sensor is about the same price.

 

cool thanks, i hope this works...ill just describe the sensor to the dealer and see wut happens...ill post my experience, thanks man

 

If your car temp sensor is on H and then shuts off then your water pump went out. Dont know if you are over heating or anything. It will show signs of everything been normal.

 

y dont u bleed the system before u buy any parts...its free and takes 15 mins to do

 

That's what I suggested right at the top of the thread.. apparently he's intent on replacing parts without diagnosing the true problem.

 

dude you need to let all the air out of the system... you have a air pocket.. it sometimes takes DAYS to get rid of...

 

OR as i said above, i intend on waiting for more responses before buying new parts....how do i bleed the system by the way?...i can bleed brakes, bleed steering fluid, whats the process for bleeding my coolant system? thanks...

 

look at your service manual...there is a bleeding screw. I have also had to work air pockets out by squeezing my lower radiator hose before, and burping the air thru the radiator with the cap off....this took about an hour though. Goodluck.

 

My '99 Max has a similar problem. The needle shoots up to H right after start up. It doesn't matter if its been sitting for an hour or overnight in 40 degree weather. I took it to a local garage and they kept it for three days trying to figure out what was wrong. The ECU threw no codes, they replaced the sending unit - twice. Their conclusion was that the guage or the wiring is the problem. They tested the car repeatedly and it never over heated.

Long story short, I took the car back from them and didn't have the guage or wiring replaced. That was 2001 when my Max had about 80,000 on the clock. She runs fine today with 167,000 on the clock. Every now and then the guage works right but most of the time its up above the H. No codes have ever been thrown. I change my antifreeze yearly. I've learned to live with it. Its part of her charm

 

+1 on check the water pump.

 

looks like im going to have to check the water pump, its not smoking or anything like that, but i guess it might be a combination of the car really overheating and the sensors begin bad...i heard boiling the first time it happened, by the radiator....but today no boiling, no smoke, nothing crazy and the needle was well above the H....maybe it IS the water pump and the bad sensor....gonna just get it diagnosed by a mechanic around here

 

Radiator cap.

 

cars been sitting in the garage, been taking my other car out instead, couldnt make it to mechanic....how do i CHECK if its the water pump? and should i just borrow a friends radiator cap to see if it is the radiator cap??? thanks...

 

ok, heres an idea i got from Dathrillr, on here...

i just had the vb mod, pro torque converter, and bulletproof tranny installed....and have the tranny cooler sitting here, probably installing this weekend....its kid of warm out...do u guys think that this is a major factor? i think he makes sense....he says the tranny fluid is heating up and affecting the radiator temp/fluids.....

could this be it? god i hope so, im installing the tranny cooler when i get home....

 

i installed the tranny cooler, all went well.....okay still overheating, but now at idle, and im actually overheating now cuz i heard boiling, i let the car idle for 20 minutes and needle got up to 80% and i heard boiling in the radiator....wut the hell could it be now?

some of u seaid check water pump, but im thinking i would leak coolant if i had a bad pump wouldnt i??? i dotn know, still need some help, thanks fellas...

 

1/ When you hear boiling in the radiator, is the radiator very hot? If you drop water on it, does the water boil? What if the boiling sound you hear is air in the radiator.

2/ Does the fan come on? If you turn on AC, do both radiator fans come on? If so, does the temperature drop?

 

thanks uncle max, its very very hot to the touch, i cant put my hand on anything connected tot the radiator...both fans come on and temp almost stays the same...at like 80% and very slowly rising anyway....

can i ask u this? if it is air i hear in there....would these be the symptoms? if its just air i can get the air "pumped" out of my system at mechanic....the upper passenger side hose is where i hear the "boiling", "gurgling" sound.....any other suggestions....ill try doing this at a shop tonight...

 

are both your upper and lower radiator hoses hot when the car is 'hot'? If not then you have an air lock. Look at your service manual, there should be a spot where you can open an air bleeder if this is the case. Or do like I did an just work the air out of the system by burping the air out of the system thru the radiator

 

the whole radiator and all connecting hoses are piping hot, i cant touch anything in that area....i tried burping it, ive gotta see if there is an air bleeder....but as i said its not just one hose, i only heard the boiling in one hose...thanks guys..

 

I think the water pump is working fine. That's how the hot coolant gets to the radiator.

I don't think it is air lock either. For an air lock would over heat the engine, but won't make the radiator and hoses very hot.

Not due to the hot AFT fluid either, since the car is not even moving.

Since your radiator is fairly new, it should not clogged either.

Do you see oil in the coolant? What if there is a head gasket leak? What is the condition of the egnine oil?

Basically, either the radiator is not removing enough heat as it is supposed to. Ot heat is introducing into the coolant way higher than normal.

 

i just changed the oil about a week ago, and the coolant was as green as could be last i checked, i will def check again though....just to be safe, how do i bleed air out? i tried the burping method is there another method? like letting the car run removing the radiator cap and putting it back on? bleeding screw location? i dont have a fsm...

 

by the way my car has 81k on it, and its a 97 max....new transmission and i have a mevi, if this info helps at all...

 

If the engine is overheating, that means the coolant is getting hot, which means everything that the coolant touches (hoses, radiator) can get hot.

The OP is making this much harder than it needs to be. A lot of simple and cheap suggestions have been offered - and we have never gotten word if he has tried those things, e.g. replace the radiator cap, bleed air out of the system (thats what it sounds like to me), etc. If you read back far enough, you'll see this started after he changed the coolant.

 

Run the car with the radiator cap off. Keep squeezing the lower radiator hose (careful of the fans and belts). They should feel firm if all the air is gone. If you notice bubbles popping out of the radiator (since the cap is off), keep doing it until there is no more bubbles. Let the car reach operating temp, you should see the coolant moving around a little - i.e. the thermostat has opened up and coolant is circulating through the block. You will probably need some 50/50 coolant/distilled water mix to top off the radiator has air is purged from the system. I let my car run with the cap off for 15-20 minutes. Then put the cap back on and let the car cool down completely, and check the coolant level.

 

honestly, reading through this hole thread it sounds like you messed up the mixture of coolant, and put in too much water, or more likely, not enough water. Are you sure you mixed it 50/50? cause you can't put straight coolant into there, you need to add in 50 percent distilled water....

 

Purging air from the system is not that hard. I changed coolant many times and don't recall any special procedure. Post #31 is how I did it.

There is another possibility is the new radiator is already clogged with debris from the bad hose???

And when you put in the thermostat, did you make sure the air bleed hole (on the thermostat) is at the correct position. It has to be upper position.

The best way to solve this is to work backward to when this problem happens and what was done to the car just before that.

Do the simple things first, though, before changing any part. Once you got it figured out, let us know. I am very curious.

 

well fellas...i borrowed a radiator cap, didnt work, thermostat was new, radiator new...dont know wut other updates, tranny cooler installed...uhmmm....

tried burping it the other way that didnt work i will try post number 31 today and pray that will be the end of it...

and the coolant i bought was pre mixed already.....

after post 31, if that doesnt work im selling the car...lol thanks guys, beed a great help...

 

CASE CLOSED thanks guys.....i did post 31 had my friend who is a mechanic come take a look at it....he brought over some pressure cap thingy and said i had a lot of air in there....i showed him how i did it (post 31) and he said i just didnt do it long enough, but it was workin....car no longer overheats....tj max is back, lol thanks fellas

www.cardomain.com/profile/tj_maxx

 

good deal, glad you got it fixed! That was the same thing I was telling you to do (post 31), I guess he just described what you need to do better

 

Now if you had listened to what I had told you in post #3, Item #1 right from the start, you would have had the problem fixed Anyway... glad you are back on the road!.

 

lol thanks, but wut if i listened to item number 2 or 3, i take in a bunch of options and start with the cheapest...but thanks anyway, this site is like the FSM for our cars...

 

WTF!!!! still overheating, at like 80% now, its going in to the mechanic tomorrow morning, screw this....

 

alright i went they told me its a clogged radiator and 300 bucks should do it....

i can change a radiator myself...instead i went home, and i pulled the radiator out and ran a hose through it...when i ran the hose through it the water came out the other end with the same exact force it did before i installed it 6 months ago....maybe a coolant flush from midas or something would help? is there any other way i can test if the radiator is clogged? i think the mechanic was an ******* since he felt the hoses, said i need a new radiator and 300 bucks was for the radiator, forget the labor...

wut if i spend 400 bucks total and it isnt the radiator? hes not giving me my freakin money back....this bites...wut do u guys think the next step is? now my needle at idle stays okay, if i rev up for a little bit, it goes up to about 80% then eventually cools back down at idle...to maybe 60% so it actually has gotten better than before....thanks for the help i could have sworn this was over....