Lexus ES 300 Overheating
08-05-12, 11:17 AM
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Lexus ES 300 Overheating
HI there! i own a Lexus ES 300 and have been having problems because it has started overheating recently 
. when it first happened i checked under the hood and realized there was no coolant in the car. after adding some i drove up to the local 7 11, and back, the car was still over heating and the coolant was bubbling.
it has been a few days since then, and I I'm trying to see what is wrong now but really have to clue were to start. the coolant is completely empty, so could is possible be leaking? I also asked Auto Zone what some of the common problems could be and they told me to check my thermostat, and water pump, but I'm not sure sure how to tell if they are working or not.
any help would be awesome! and if you chose to reply please dumb it down for me, because i have just recently tried doing self maintenance, and know little to nothing about cars
Thank you!
. when it first happened i checked under the hood and realized there was no coolant in the car. after adding some i drove up to the local 7 11, and back, the car was still over heating and the coolant was bubbling. it has been a few days since then, and I I'm trying to see what is wrong now but really have to clue were to start. the coolant is completely empty, so could is possible be leaking? I also asked Auto Zone what some of the common problems could be and they told me to check my thermostat, and water pump, but I'm not sure sure how to tell if they are working or not.
any help would be awesome! and if you chose to reply please dumb it down for me, because i have just recently tried doing self maintenance, and know little to nothing about cars
Thank you!
08-05-12, 11:37 AM
#3
First thing is to see where it's leaking. Fill the system and let it run with the hood open and watch. Assuming the fan is turning on, my best guess without any additional information is probably the radiator cap. Best way would be to pressure test the system but it doesn't sound like something you can do or have the tools to do.
08-05-12, 12:07 PM
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thanks for replying so fast!
The Fan comes on, and seems to be running the same as it always has. It seem like it could be a major leak, I added more coolant, and drove it up the street and back down to heat it up ( that might have not been the best thing to do ) and then watched it to see if i could notice anything. the fan was on but the coolant was bubbling again, it didn't seem like anything was leaking but when i came back and checked the coolant was emptyed out
how would i go about testing the Radiator? what tools might i need?
The Fan comes on, and seems to be running the same as it always has. It seem like it could be a major leak, I added more coolant, and drove it up the street and back down to heat it up ( that might have not been the best thing to do ) and then watched it to see if i could notice anything. the fan was on but the coolant was bubbling again, it didn't seem like anything was leaking but when i came back and checked the coolant was emptyed out
how would i go about testing the Radiator? what tools might i need?
08-05-12, 12:13 PM
#6
Lexus Test Driver
How many miles on your 1996 (according to your profile) ES?
First thing I would do, is keep the radiator cap open and start the car. And, add fluid continue adding till the system is full and all the air bubbles have stopped. (remember not to open the radiator cap when hot, wait till engine is cold).
Are there any visible leaks? How's the engine oil, do you see any coolant mixed in it?
When it overheated the first time, how far did it get into the red? Please tell me it wasn't pegged on "H".
First thing I would do, is keep the radiator cap open and start the car. And, add fluid continue adding till the system is full and all the air bubbles have stopped. (remember not to open the radiator cap when hot, wait till engine is cold).
Are there any visible leaks? How's the engine oil, do you see any coolant mixed in it?
When it overheated the first time, how far did it get into the red? Please tell me it wasn't pegged on "H".
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08-05-12, 04:59 PM
#10
ETx, you have had a lot of suggestions thus far. And good suggestions. But by your own admission, you know little to nothing about cars so let's do some educating here to help you make sense out of the suggestions.
First off, the engine gets hot from burning gasoline (ok, I am "dumbing" it down, remember?) . That heat needs to be removed from the engine to keep it from overheating. So, coolant which is a mixture of antifreeze and water, is circulated throughout the engine. There are little passages designed into the engine block and heads which carry the coolant. The "water" pump (actually its a "coolant" pump) pushes the coolant around the block picking up the heat generated within the engine.
Now, besides circulating inside the engine, the coolant is passed through the radiator at the front of the car. The air blowing past the cooling fins in the radiator, carries away the excess heat into our atmosphere where it causes global warming and kills polar bears. Ok, maybe that last part is not entirely true.
If you can imagine this, the pump pushes coolant around the engine and the radiator in one big loop. In that loop is also a thermostat. The thermostat is a bimetal device that reacts to heat. It is like a switch that blocks the flow of coolant when the engine is cold but opens up and allows coolant to flow when the engine gets hot.
Besides circulating through the engine, thermostat, the pump and radiator, the coolant also flows through the passenger compartment of your car by passing through the heater core. The heater core is actually a little radiator which can disperse heat within the cabin to warm your tootsies in the colder winter months.
Ok, so what can go wrong here? Well, it is a pretty simple system but any blockage of the normal flow of coolant can cause overheating. And what could block the flow? Well, the thermostat may not be opening up enough to allow sufficient coolant to flow. The way thermostats are designed, however, is usually that they stay open when they go bad. The engine then actually takes a lot of time to warm up when its cold. Definitely not your case. Another thing that happens to impede the flow is a partially blocked radiator.
Now, there are also nasty things which can happen within the engine to create more heat than the cooling system was designed to handle. When (or if) the system gets overwhelmed with more heat that it was designed to carry away, the engine will overheat. If a head gasket were to fail, it could allow some hot exhaust gases, which normally go out the exhaust pipe, to super-heat the coolant in the engine water jacket. That also usually causes the coolant to get a little foamy as well. A bad head gasket can also suck the coolant into one of the combustion chambers and "burn" it(it really turns to steam). That results in loss of coolant which eventually runs the system low and overheating results. You do not see any visible leaks, only a slight whitish steam coming from the tailpipe when the engine is running.
There are also other things which could affect the cooling but you now have the basics. When troubleshooting, ALWAYS look for the really obvious and simple things. Because problems are usually (and hopefully) somewhat simple. The first thing to do is to make sure the system has the proper amount (and mixture) of coolant. Since you are in Tx in the middle of the blazing hot summer, it might be a good idea to do some testing without the A/C being on. If you are simply at a "tipping" point between maintaining proper temperature, leaving the A/C off may help. If it does, then you probably have a somewhat restricted radiator. Clogging happens over time especially when the coolant is not flushed and changed every few years.
Well, this is kinda long so I will quit for now. Let us know what you find.
First off, the engine gets hot from burning gasoline (ok, I am "dumbing" it down, remember?) . That heat needs to be removed from the engine to keep it from overheating. So, coolant which is a mixture of antifreeze and water, is circulated throughout the engine. There are little passages designed into the engine block and heads which carry the coolant. The "water" pump (actually its a "coolant" pump) pushes the coolant around the block picking up the heat generated within the engine.
Now, besides circulating inside the engine, the coolant is passed through the radiator at the front of the car. The air blowing past the cooling fins in the radiator, carries away the excess heat into our atmosphere where it causes global warming and kills polar bears. Ok, maybe that last part is not entirely true.
If you can imagine this, the pump pushes coolant around the engine and the radiator in one big loop. In that loop is also a thermostat. The thermostat is a bimetal device that reacts to heat. It is like a switch that blocks the flow of coolant when the engine is cold but opens up and allows coolant to flow when the engine gets hot.
Besides circulating through the engine, thermostat, the pump and radiator, the coolant also flows through the passenger compartment of your car by passing through the heater core. The heater core is actually a little radiator which can disperse heat within the cabin to warm your tootsies in the colder winter months.
Ok, so what can go wrong here? Well, it is a pretty simple system but any blockage of the normal flow of coolant can cause overheating. And what could block the flow? Well, the thermostat may not be opening up enough to allow sufficient coolant to flow. The way thermostats are designed, however, is usually that they stay open when they go bad. The engine then actually takes a lot of time to warm up when its cold. Definitely not your case. Another thing that happens to impede the flow is a partially blocked radiator.
Now, there are also nasty things which can happen within the engine to create more heat than the cooling system was designed to handle. When (or if) the system gets overwhelmed with more heat that it was designed to carry away, the engine will overheat. If a head gasket were to fail, it could allow some hot exhaust gases, which normally go out the exhaust pipe, to super-heat the coolant in the engine water jacket. That also usually causes the coolant to get a little foamy as well. A bad head gasket can also suck the coolant into one of the combustion chambers and "burn" it(it really turns to steam). That results in loss of coolant which eventually runs the system low and overheating results. You do not see any visible leaks, only a slight whitish steam coming from the tailpipe when the engine is running.
There are also other things which could affect the cooling but you now have the basics. When troubleshooting, ALWAYS look for the really obvious and simple things. Because problems are usually (and hopefully) somewhat simple. The first thing to do is to make sure the system has the proper amount (and mixture) of coolant. Since you are in Tx in the middle of the blazing hot summer, it might be a good idea to do some testing without the A/C being on. If you are simply at a "tipping" point between maintaining proper temperature, leaving the A/C off may help. If it does, then you probably have a somewhat restricted radiator. Clogging happens over time especially when the coolant is not flushed and changed every few years.
Well, this is kinda long so I will quit for now. Let us know what you find.
Last edited by randal; 08-05-12 at 05:06 PM.
08-06-12, 11:45 AM
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How many miles on your 1996 (according to your profile) ES?
First thing I would do, is keep the radiator cap open and start the car. And, add fluid continue adding till the system is full and all the air bubbles have stopped. (remember not to open the radiator cap when hot, wait till engine is cold).
Are there any visible leaks? How's the engine oil, do you see any coolant mixed in it?
When it overheated the first time, how far did it get into the red? Please tell me it wasn't pegged on "H".
First thing I would do, is keep the radiator cap open and start the car. And, add fluid continue adding till the system is full and all the air bubbles have stopped. (remember not to open the radiator cap when hot, wait till engine is cold).
Are there any visible leaks? How's the engine oil, do you see any coolant mixed in it?
When it overheated the first time, how far did it get into the red? Please tell me it wasn't pegged on "H".
and i didn't see any leaks, but I'm not sure how much fluid is in my system so there may not be much to leak.
the first time it overheated it pretty much went as far H as it could
it takes about 10 minutes of driving for it to overheat
08-06-12, 11:50 AM
#12
Lexus Test Driver
I will try this, when you say fluid you mean coolant in the little coolant tray, and water in the radiator right? sorry i just wanna make sure
and i didn't see any leaks, but I'm not sure how much fluid is in my system so there may not be much to leak.
the first time it overheated it pretty much went as far H as it could
it takes about 10 minutes of driving for it to overheat
and i didn't see any leaks, but I'm not sure how much fluid is in my system so there may not be much to leak.
the first time it overheated it pretty much went as far H as it could
it takes about 10 minutes of driving for it to overheat
But, you are supposed to mix the coolant and distilled water before putting it into the system. Make a 50/50 mixture, and then put it in the radiator and overflow pot. Remember make sure the engine is cold before opening the cap, you don't want boiling hot coolant in your face.
That's not good, if the needle was pegged on H. That's really bad news. You could have blown a head gasket. Let's hope not.
08-06-12, 11:56 AM
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Yes, by fluid I mean coolant.
But, you are supposed to mix the coolant and distilled water before putting it into the system. Make a 50/50 mixture, and then put it in the radiator and overflow pot. Remember make sure the engine is cold before opening the cap, you don't want boiling hot coolant in your face.
That's not good, if the needle was pegged on H. That's really bad news. You could have blown a head gasket. Let's hope not.
But, you are supposed to mix the coolant and distilled water before putting it into the system. Make a 50/50 mixture, and then put it in the radiator and overflow pot. Remember make sure the engine is cold before opening the cap, you don't want boiling hot coolant in your face.
That's not good, if the needle was pegged on H. That's really bad news. You could have blown a head gasket. Let's hope not.
and i have been using Peak 50/50 ready to use coolant, it's green haha
08-06-12, 12:03 PM
#14
Lexus Test Driver
Well, once you open the radiator cap, turn the engine on, and keep filling in coolant till the level doesn't drop any further. When the level doesn't drop you will know that the radiator is full. The reason I'm telling you turn the car on, is so that once the thermostat opens you can put more coolant in there and burp the system.
Also, like I mentioned before take a look at the dipstick and see if there is coolant on it mixed in with the oil.
08-06-12, 12:47 PM
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ok, so i put coolant into my radiator i don't think i filled it all the up though, because i wasn't sure if i was going to get blasted with hot coolant. i filled it tell i saw the coolant top off and then drop, and i stopped there because the temperature on my dash was about 1/3s way to H
I'm not sure there was much, if any coolant in my radiator though, because it more or less took all the fluid i had, witch was about 2/3s of a gallon.
i didn't see any leaks, is there a certain area i should be looking at? i just kinda scanned under the hood, and car for any kinda drops but didn't see anything
there was also no white smoke coming from my exhaust, but i may not have been looking at the right time, if it were to be coming out would it just simply be when the engine is on or when the gas pedal is being pressed down?
my oil looks fine to me, if there were coolant in to oil there green steaks on my dip stick right?
I'm not sure there was much, if any coolant in my radiator though, because it more or less took all the fluid i had, witch was about 2/3s of a gallon.
i didn't see any leaks, is there a certain area i should be looking at? i just kinda scanned under the hood, and car for any kinda drops but didn't see anything
there was also no white smoke coming from my exhaust, but i may not have been looking at the right time, if it were to be coming out would it just simply be when the engine is on or when the gas pedal is being pressed down?
my oil looks fine to me, if there were coolant in to oil there green steaks on my dip stick right?
