if the heatercore is clugged up, is it possible to cause overheating during traffic?
When I drive on the high going over 70MPH the temperature is fine 180F, but when I stop at a red light, the temperature goes up to 230F in less than 2 minutes.
I do get heat from the vents, but not as much that's why I want to ask if anyone in here ever had a problem with the heatercore clugged up and causing the car to overheat in Traffic.
when your stopped and the car is overheating, check to see if the cooling fan comes on under the hood near the front, next to the radiator. If it doesnt, theres your problem. You either need a new fan or connections.
Speed costs... How fast ya wanna go??
<a href="http://mywebpages.comcast.net/pj1987">My old cars</a>
Overheats in city = cooling fan not coming on. Relay, fan itself lots of possiblitys there.
- 2004 Cavalier - 124k, owned since new
I agree with them, but I would also make sure your not having a problem compounded by DexCool.
If you haven't flushed your coolant system, This would be a great time to do that.
The system is full. I have about a 70/30 Mix of Dex and water.
70% Dexcool and 30% water because sometimes it gets down to 28F at night.
The fan does come on, I touch the Radiator and its cold on one side and hot on the other side when the car is overheating.
ohh, you know what I do when the fan kicks on and does no good to cool down the temperature?
I Rev it up to 2500RPMs RRRRRRRRRRRRRRRRRRRRRRHHHHHH!!!!!!
in about 30seconds the temperature drops to 195F
Why? I don't know
or I can just turn the AC with the heat full speed and that cools it down
Turn the the heat at full speed and Rev it up to 3,000RPMs and the temperature drops to 195F is what I was trying to say.
The fan is fine.
ok.. when your car warms up.. feel the hoses from the top and bottom of the radiator. make sure there both hot. Seemslike your water pump may be missing a few fins as a last resort. But that is def. a last resort. Also when checkign the hoses to see if the thermostat is bad make sure that hose stays cold intill the car really starts to heat up. If both hoses warm up equally it is almost as bad as it being shut.
Speed costs... How fast ya wanna go??
<a href="http://mywebpages.comcast.net/pj1987">My old cars</a>
so,
A. make sure the thermostat bottom radiator hose stays Cold before the car heats up to 180F degrees. (I have a 180F degree Thermostat)
The top radiator hose should be warm.
or
B. If both hoses feel warm, before 180F degrees it means... that __________
Do what? I'm sorry, I didn't get that part.
That means your thermostat is stuck open, and is passing by the block to fast to absorb the heat.
Speed costs... How fast ya wanna go??
<a href="http://mywebpages.comcast.net/pj1987">My old cars</a>
One hose was hot and the other cold before 195F
Upper HOT
Lower COLD
What if the car's Temperature is about 180F-190F at high way speeds and there's only
50% hot air (heat) coming from the AC vents and the heat is turned to hot.
When I come to a Stop, after the Exit from the high way, the Temperature goes up to
about 230F degrees in less than 1 minute. The fan kicks on but its worthless, and there's 50% hot air coming from the vents. Later when I start going and I push the Accelerator and go up to 3000RPMs the temperature drops to 195F in less than 30 seconds.
That's the thermostat heating up, and when it gets hot it opens and cools the car.
I remember back in the days the heat was so hot it burned my face and I had to turn it 1/2 way. Now, no matter how hot I turn the heat, its not as hot as it used to be and it overheats when I stop after running for a long period of time.
I remember I had this problem last summer, so I took the thermostat OFF for the summer.
Later I'd put it back on because it was getting cold and my car was running way too cold.
so cold- it was at the 100F degree line, and of course no heat.
Got me a new thermostat, and it did okay for a while but now the problem came back and I'm not taking the thermostat back off again because its way too cold and I need my 50% heat when I'm driving.
I have the 2.4.
the 2.4 has a bracket right at the thermostat and water-pump that goes to the heater-core.
that makes me wonder if the heater-core is clogged up and making the water around that area (water-pump, thermostat, heater-core bracket) not circulate keeping the thermostat too cold, unless I give it gas to heat up the thermostat's spring and that's when it opens and cools down the engine.
if I have to put money on the table, I would say is the heater-core clogged-up but I'm willing to take more advice
That's a 5 hour Job.
I did a compression test on each cylinder and it was between around 125PSI-130PSI
the gage has even numbers
100-120-140-160-180-200-ect... and it was between 120PSI and 140PSI
The book also says anything over 100PSI is good.
The only leak I have right now is when I let the temperature go over 230F degrees.
right when I stop, pressure gets higher. The coolant container CAP can only hold 15PSI
so the car most creat a lot of pressure after I stop
When I'm on the highway the temperature stays @ 180F degrees and I can drive for
hours and hours
Sounds like a water pump that is going bad and not pumping enough water through the system at idle.
The water pump was replaced and there was nothing wrong with it.
installed the new water pump but the problem was never fixed.
I think I'm just going to take the thermostat off out and let it run free and cold.
I took it to another shop and they said it sounds like a bad head gasket.
the heatercore can not cause overheating.
When I turn the heater on, it sticks. smells like cat piss YUCK!!
the blown head gasket is caused by over heating and the coolant escapes form the water pockets around the cylinders and goes into ur cylinders... how is ur coolant level? seems like ur not getting proper cooling through ur radiator also. possibly clogged radiator? when was the last time u did a coolant flush? what did the coolant look like?
MY 2003 SUNFIRE 15.6@86mph
"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001
The radiator was 9 months ago.
I did a flush about 1 month ago when I intalled the thermostat.
The coolant looked fine.
I start the car and let it warm up. The temperature outside in the morning is about 25F
and takes a while to get up to 180F, then it stays there.
when I drive it, it goes up to 195F but there's not much heat. the heat feels warm, not too hot. Now the heat stinks. To me smells like cat piss.
How can it be the head gasket if its not smoking?
There's no oil in the coolant when I check it, there's no coolant in the Oil, there's no white smoke coming from the exhaust or antifreeze.
The heatercore hose gets really hot but there's not enough heat coming from the AC Vents.
The radiator was replaced 9 months ago.
I have another question.
If I have a blown headgasket, How come it runs okay when I remove the thermostat?
The car never gets hot, but what about all the combustion gases going inside the cooling system? won't they go inside and cause air pressure inside the cooling system?
with out the thermostat, when I get stock in traffic the car gets hot, and the temperature goes up 180F, but then I turn the AC on, Fan comes on and the temperature drops down to 150F (the second line)
Why can't it do the same with the thermostat ON? I don't get it.
I think I just found what I was looking for and kinda explains why the thermostat won't open and maybe why I have no eat.
"You may have an air pocket during startup due to leaking head gasket or antifreeze leak (or combustion gases accumulating around the thermostat.) Try flushing cooling system to get junk out. Pressure test your cooling system to eliminate the possibility of the blown head gasket. When you first start your car leaking head gasket will introduce gas into the head cooling space. It will replace fluid from the area. The thermostat is closed so the gas has no place to go. The gas acts like an insulator so it will delay heat transfer to the thermostat. But other parts of the engine covered with the fluid blanket will heat the water up to the boiling point. Finally engine is hot enough to cause thermostat to open and let the gas go into the radiator. After the gas goes the overheated water and that's what causes your needle to rise on the gauge. Further operation is normal because thermostat is open and the gas goes to expansion tank as soon as it gets into the system. You need to repair the leak as soon as possible if that's the cause or you will end up with warped head due to spot overheating"
I think I found more info:
the most obvious sign thow is pressure still there in the morning when everything has cooled down.. as there will be if the rest of your system is leak free except for the pressure leak between cylinder and waterways..
compression or leak-down tests will not show up this type of leak thow a sniffer test probably will.. i think all saab gaskets go this way before they really blow..
so...
I need to check the if there's any pressure in the morning, and Compression Test sometimes don't mean nothing
I rather put a new head, if I have a headgasket leak or just junk the motor and replace it.
ok removing the thermostat will allow the system to flow freely and if u ran without it in ur engine would not get to proper operating temperature and will effect ur gas mileage also.
ur warm air into the passenger compartment problem may have to do wiht the air temperature blend door. its the door behind the heater core that regulates the air coming form the heater core. as for the smell that could be bacteria build up in the tubes of ur HVAC system. is ur complaint of warm air (not hot air) durig the period while u have ur thermostat out? that will be ur problem too bc u get heat from the engine coolant as it flows throught he heater core the heat transfers to the fins on the heatercore and when air bloews through the heater core and the temp blend door is open thats how u warm the passenger compartment
the air pockets will be worked out of the system itself bc we have a self bleeding system. if u dont have a radiator cap and have just a coolant resevior then ur prolly running a self bleeding system.
i dont think you have a bad head gasket. if u pressure tested it and it passed then i wouldnt look that way. it could become a possibilty if the car continues to over heat. but what i truely think is its the thermostat. bc it is possible to get bad parts, not everything is perfect. ur thermostat sohuld open up between 180-195 degrees. also the engine gets hotter in traffic bc its not getting air pulled through the radiator. so when stitting still there is no proper air flow through the radiator to cool the fluids thats where the fans kick in and suck air through ur radiator. the fans suck in not push air out....
i tried to answer ur questions throughly anytinhg else pops up feel free to ask.
MY 2003 SUNFIRE 15.6@86mph
"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001
Thanks for your reply.
Spring 2005
I had that problem last year, and I replaced the thermostat.
got a new thermostat and it didn't work, got me another thermostat, and it didn't work. so I had to remove it and let it run cold.
I replaced the water pump, and installed a new radiator and the fan switch, and temperature sensor.
Summer 2005
During the summer, I was driving the car with out the thermostat and it was running cold. maybe 150F during traffic it did go to 195F and I turned the AC on, the fan turned ON and the temperature went down to 165 close to the second line.
Winter 2005
the temperature out side was getting colder and colder. 30F and the car was never hot. it didn't even go over the second line, it was running around 120F in traffic and below 100F on the highway and of course, no heat.
Winter 2005 New NAPA 180F degree thermostat.
I tested the thermostat with hot water and it was good.
After installing the thermostat, the car did great for 30 days.
I remember sitting in traffic and driving slow and the temperature never passed over 230 to turn the fan on it just stayed in the middle 195F
December 2005
After getting off the highway, the temperature started to go up in seconds until I started
moving.
I had to rev it up to 3000RPMs and turn the heater with the fan to cool the engine down.
now its getting to the point where I can't go below 70MPH or it will overheat.
the tricky part is that when I take the thermostat out, there's no more overheating and that's what I'm going to do, and put cardboard on the radiator to keep it warm.
I did that before when I took the thermostat out, and the car was still cold. I did leave a Gap to let fresh air blow in the radiator.
My question is this.
if my head gasket is "BLOWN" why is it okay to run the car with out the thermostat?
I think if I have combustion gases going inside the cooling system, if I take the thermostat out, where would all that pressure go? it should blow the radiator.
think about, gas going inside the cooling system building up and up, but where would they go if I can't find a leak. that would be my question
ohh, I'd check if there was any pressure in the morning.
I found nothing. I removed the overflow cap real slow and there was no pressure.
that article said that the pressure would be at the overflow in the morning, but it wasn't'.
I'm going to check the thermostat tomorrow. Ohh3.
not right now because its cold and wet. Thanks again for the tip.
I have to remove the tire, remove the fender cover, remove the cover exhaust thing, get a 8mm sock with a long extension.
my car is sitting on the drive way for the pass 3 days.
I'm not messing with the thermostat.
I checked the oil and it was fine.
it looks kinda red, I think
i think it might be from coolant getting inside the head but when I let it run it don't smoke white smoke like it would normaly do when the head blows.
What about cracked head? uhmmmmm... don't know
Tomorrow I'll drop her off.
its goinna cost me $$$$$$$$$$$$$$$$$$$$$$$$$$$
good luck with that
MY 2003 SUNFIRE 15.6@86mph
"A N/A ecotec is not gonna give Honda's and Mitsu's that much of a run for their
money unless their blown or bottle fed.GM is still smokin crack!"
~1QWKZ24
www.streetracing.org, 08/2001
