Strange Overheating Problem

[SrS13]

I have replaced the radiator, water pump, and thermostat so i know neither of these are my problem.

my overflow tank overfills when it overheats I never have to refill my system. I bleed my system after I replaced all my parts, but did I not do it right? I know it is not leaking.

please help:help :help

[MaineExport]

Take out your new thermostat and boil it to make sure it's working properly. I had a similar issue a while back... I replaced the thermostat... still overheated... replaced the water pump... still overheated... flushed and pressure tested the radiator... still over heated... I bled the coolant about three-dozen times... still overheated.

Finally, I took out the brand new thermostat and discovered that it was defective. It would not open in boiling water or under the torch. I have come to find out that this is an all too common thing to happen.

Also... how are you bleeding the coolant? Try using the bleeder screw above the thermostat. Unless you have an SR... in which case I don't know if it even has one.

[SrS13]

I bleed the system by letting the engine reach operating temp. then I remove the radiator cap and refill as it needs more. I really dont want to have to drain my coolant to remove the thermo then bleed all over again, but if I have to I will. Thanks for the help

[SRdave240]

The SR has a bleeder hole on top of the upper radiator hose outlet from the block. It also has a block drain plug just beneath the top coolant line that feeds your turbo. Fill your system this way...

remove radiator plug, bleeder plug and block plug.Jack up front of car.replace radiator and block plugslowly fill with water/coolant mix until it squirts out bleeder holereplace screw in bleeder holecontinue filling until full.

Also try a 16 lb 300zx radiator cap and a 20-25% colant mix with Redline water wetter.

good luck - werkt for me!

[leper421]

I have replaced the radiator, water pump, and thermostat so i know neither of these are my problem.

But did you replace the radiator cap too? If its going bad and cant hold the pressure, your coolant will boil at a lower temp.

[Hijacker]

But did you replace the radiator cap too? If its going bad and cant hold the pressure, your coolant will boil at a lower temp.

yeah. that happened with my old eclipse. i couldn't figure out what the problem was, and finally my dad and i decided as a last ditch effort before taking it to someone was check the cap. it had eroded away to bare metal. we replaced it, and when the system repressurized, i blow my top hose! it had hardened from the excess standing heat.

[YomnyM]

I have a prob with overheating too hope someone could help me out, sorry don't mean to jack the thread it was just similar to my prob. My car is fine once it starts warming up it starts to heat up i guess, the temp needle is at it's normal range, the overfill tank doesn't fill up at all, is empty and the car starts to hesistates then i start hearing detotation or the valves, sounds like when you get crankwalk in eclipses(if anyone knows), or when you put really bad gas in your car. If i keep on driving th ecar starts smoking white smoke, and starts to burn oil. I checked the dipstick under this conditions and the oil seems to be boiling, smoke comes out of the dipstick tube. The car also tends to turn off. Next day when the car is cold it starts up fine and drives fine, until it starts warming up. Thermostat is fine, pump is fine and there is no water leak. I ran the car with the radiator cap off and well i turned it on (not moving) and checked the water level, it didn't move but i saw even when cold smoke coming out, once it started to heat up it got more intense. Any idea what this could be, i'd really really appreciate any input or opinions, please don't be an ***, i don't need that right now. thank you vebry much for your time.

[kouki-gymkhana]

Sorry to say but it sounds like you've blown your headgasket. The white smoke suggests that you're burning coolant. Check the oil again to see if it appears white or milky as this is the case in about 70% of blown headgaskets.

Start thinking about replacing it... If you're going to do it yourself, it'll probably take 2 full days of work if you're an average mechanic and allowing for the everpresent snafus that occur when you do engine work.

Hope this helps.

[YomnyM]

But whats wierd is that the car starts fien the next day or after letting it cool down for hours, it starts perfectly and it has power, wouldn't a blown head gasket affect the car at all temps.? Thanks for your response.

[gatr]

Its the headgasket ..for sure ....

[CanadianCoch]

I took this from a previous post I made, should help you find yoru problem. Definately replace your radiator cap, as well do the PROPER procedure for bleeding air from the system.

Here goes!-----------------------------------------------------------------------------

First thing to try is seeing if you have an air bubble. At the end of this essay is the procedure to do a PROPER bleed of the coolant. This is the cause of most people've overheating. FIRST do this, and if it does not fix the problem, proceed through the following steps to find your problem.

1. Does your temperature gauge go over half when the coolant is bullbing? if so then your car might have overheated and the head gasket might be blown. Next time you drive for an extended period of time, keep an eye on the temperature gausge.To See if it's your headgasket going bad, do this.When the car is cold, open the radiator cap and turn on the car. If radiator fluid shoots out then your head gasket is bad. As well, you will find oil in the coolant, which would also show a bad head gasket.

2. Sometime you've been driving for a while and it's warm, check the lower radiator hose when you turn it off. The top hose should be almost too hot to touch, and the bottom one (it leads ino the thermostat, consult a chiltons or fsm). The bottom one shouldn't be as hot, however you should feel some warmth. If it isn't warm, then it's most likely your radiator (thats what my problem ended up being after hours of work and replacing parts). If it's not the radiator, proceed to the next possibility.

3. Fans - is the fan attached to the belts running? What about the fan attached to the radiator? This is the A/C fan, it also goes on to help cool the temperature. This could well be the problem. See if it is running, if not then you could simply need it replaced. If you cannot see if it is running, then remove the intake, unplug the fans connector (loacted beside the battery, trace the wires from the fan to the connection and run wires from the ends to the battery. If it starts going then you know the fan itself works. Hovever it could not be working, so make sure to check your fuses as well.

4. Hoses/Radiator. Is your car leaking coolant? If your hoses are cracked or the radiator is cracked you will be leaking coolant and losing pressure as well as letting air in. Inspect the radiator with a flashlight as well as the hoses and look for any cracks or signs of coolant.

5. Check your water pump. The water pump is attached to that huge fan that circulates when your car is running. If you look closely, there are 2 small holes in the pump itself, one facing up and one facing down. Check for any signs of water leaking through these. If there is any water leaking, the water pump is bad and will need to be replaced. This is a $40 part and will require only a hours work.

6. If it's not the radiator or Head Gasket or water pump, then you're not in bad shape. I'd reccomment investing $6 in a new radiator cap and another $7 in a new thermostat and installing them. Installing the thermostat is pretty easy, and will give you the chance to refill your coolant. If you want to just text your thermostat,. remove it and put it in some boiling water and see if it opens, you can even test it to see at what temperature it is opening. There is no way i'm aware of to test the radiator cap, find a friend with a 240sx and use theirs, or break down and spend the whopping $6.

7. If you've check all of that and found your problem, you're more than likely going to have to refill and bleed the coolant. To do so, follow these steps properly to ensure all air is out of the system. Air in the system will circulate around and cause the temperature to rise, even blow the headgasket.

Bleed The Air:1. Either jack up the front end or put the car facing up on a hill.2. Start up the car and let it warm up so it's @ operating temperature, PUT THE HEAT ON FULL.3. when it's at operating temperature, open the radiator cap, and loosen the bleeder screw. This screw is located above the intake, it's a 10MM and has some japonese writing beside it. You'll see what im' talking about.4. Open the bleeder screw, and pour 50% coolant 50% water into the radiator cap, and watch as air bubbles pour out of the bleeder screw. Fill the cap as much as you see the fluid coming out.5. Squeeze all of the hoses, push them up and down a bit, but mainly squeeze themto make sure you get all of the air out of them.5. After keep doing this until you get only coolant out of the bleeded screw, no air at all. 6. Close the bleeder screw, top off and close the radiator cap, and you're done!

Hope this helped, i'm gonna see about getting this made into a faq or something, i've never written a 30 minute response before.

Any questions or problems let me know.[email protected]

[YomnyM]

Thank you very much, i really appreciate your help, i checked the radiator hoses, since a friend told me that my radiator could have been bad, and well the top one is hot but the buttom one is not, at all, so im guessing is not circulating, also, the water is like evaporating, i fill the radiator like 2 days ago and now i can't see the water line and is not leaking water at all. Thanks again for your help.

[YomnyM]

Ok i was checking my overheating problem and it seems liek the car is boiling the water in the radiator till the point that it evaporates it. I started the car with the radiator cap open and put some water since it was sort of empty, and smoke starts to come out of it, like water vapor, and then the smoke increases and it starts to like burp or bubble. Seems like the water isn't circulating is just sitting in the radiator and boiling, cause every day i have to put more water. I know that the radiator is not clogged cause i did a flush and i added water thru one side and it all came out thru the other one. I also touched the bottom hose and is hot, not as much as the lower one but it is. What do you think that is. Could it be that the water pump is not circulating the water, could that happen? Thanks a lot

[180fan]

check the thermo if the water's not circulating. thermo = valve that opens at a certain temperature aka if your system's not circulating I'd check that (well aside from the obvious "is your water pump working?"). If it evaporates the coolant, you should see vapor rising from your hood unless it's a very small leak. I'd change the cap in that instance and see if it still vaporizes. If your coolant is still dropping after you've done a flush and fill, chances are you missed some air pockets on your initial fill. I spend about a day getting the air out of my coolant system whenever I fill and wait till the evening when the air outside (I live near the beach and the air gets very cold and foggy at night) to make the coolant shrink in total volume just so I can fill more coolant (cold = things take less volume than they do at higher temps). Squeeze the upper rad hose until you dont see any more bubbles. Then cap the rad, push down on the front of the car (helps to be parked on an incline) and then squeeze the upper hose again. Uncap and fill, repeat until you can't do any more. Then turn on your car just for a short bit. Let it cool and repeat with the squeeze, cap, push on front of car, fill, restart. I get a pretty good amount of coolant in my engine by doing it that way.

[YomnyM]

There's a problem though, i just noticed that my car is leaking water. I noticed it was coming from where the engine joins the transmission, those bolts seems to be leaking, and also there are two bolts about size 14 like 2 inches apart from each other under and between the starter and the oil filter, those two are also leaking, thats very strange. Damn i think my car is doomed