My Car Is Overheating! Please Help! What To Do?

[kino1161]

I have a 1996 GS 300. My car overheated on Friday. I refilled with coolant (it was almost empty) and it was fine the whole weekend. So, today, my car overheated again, but this time it kept overheating after about 5 minutes when I would "top off" the radiator. Please help! I need to know the cheapest way to get this resolved.

Turbo.... where are you!?!?!?!?!? :cries:

[TurboGS300]

Did you turn the heater all the way up on low after changing coolant? If not you got air in the system.

B)

[kino1161]

Did you turn the heater all the way up on low after changing coolant? If not you got air in the system.

B)

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No, but when I refilled it today, I turned the heater all the up on HIGH before I drove it. Did I mess up by turning it to HIGH?? Also, if I did have air, would it take from Friday evening until now for the "air" to effect the system?

Turbo, I knew I could count on you for some kind of answer. Thanks and please reply! :D

[TurboGS300]

High is fine, low just allows it to get hotter. An air bubble can cause over heating as it's a pocket of air. How did the system get emptied? Is the cap bad? Is the top hose firm when running? becareful of letting that thing overheat too many times, the top and bottom tank are plastic and can rupture or crack. Is the fluid dirty or clean. Have you flushed it. if it overheats again turn the heater on max low to help cool the engine down.keep us posted. B)

[kino1161]

High is fine, low just allows it to get hotter. An air bubble can cause over heating as it's a pocket of air. How did the system get emptied? Is the cap bad? Is the top hose firm when running? becareful of letting that thing overheat too many times, the top and bottom tank are plastic and can rupture or crack. Is the fluid dirty or clean. Have you flushed it. if it overheats again turn the heater on max low to help cool the engine down.keep us posted. B)

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Turbo,

I don't know how it got emptied. (Maybe a leak somewhere?) How can I tell if the cap is bad? I will check the top hose when I go home for lunch. What if it is not "firm" while running? What do I do next? I haven't flushed it. So, if it overheats again, turn the temp all the way to 85 (hottest) and turn the level to low???

Next, do you think I need a new radiator after all those questions above? If so, is it easy to replace? :(

[TurboGS300]

If the cap is bad it could overheat because it will not allow the pressure to build, A new cap is $5 or $6, just replace it. If the hose is not "firm", your water pump may be bad, which means the water is not being cooled, again overheating. With the cap off and the motor cool, so you don't get scalded by the fluid. Fill the radiator up to near the top, Start the car, leave the cap off temporarily, rev the motor and see if the fluid level drops in the radiator neck. If it does the pump is probably fine. If not the pump is probably bad. If the radiator is original it could benefit from an internal and external flush. As over time sediments can clog the rows, restricting them and could cause overheating. Make sure the front of the radiator is not blocked by debris as well. Replacing the radiator is not to bad, a new one can be bought for $100+ shipping. The hardest part is removing the trans cooler lines as they're usually on there very tight and the clips are hard to get to to release the hose. B) Does the electric fan come on? It has a sensor in the bottom right corner of the radiator, when facing the front of the car, that may need to be cleaned or replaced. I replaced my water pump at the 90,000 service along with the timing belt and thermostat. At about 100,000 miles my radiator top plastic tank cracked, so I replaced it and all the hoses and installed T-Bolt clamps on all the new hoses. So my cooling system is like new. I've heard of several others radiators splitting around the same mileage, so plan on doing it in the near future. I have a new pump if yours is bad, let me know if you need it. If the engine starts to overheat while your driving turn the heat all the way up and the fan on low, of couse this will only help cool the motor if the water pump is working. How many miles are on the car?

[kino1161]

If the cap is bad it could overheat because it will not allow the pressure to build, A new cap is $5 or $6, just replace it. If the hose is not "firm", your  water pump may be bad, which means the water is not being cooled, again overheating. With the cap off and the motor cool, so you don't get scalded by the fluid. Fill the radiator up to near the top, Start the car, leave the cap off temporarily, rev the motor and see if the fluid level drops in the radiator neck. If it does the pump is probably fine. If not the pump is probably bad.  If the radiator is original it could benefit from an internal and external flush. As over time sediments can clog the rows, restricting them and could cause overheating. Make sure the front of the radiator is not blocked by debris as well. Replacing the radiator is not to bad, a new one can be bought for $100+ shipping. The hardest part is removing the trans cooler lines as they're usually on there very tight and the clips are hard to get to to release the hose. B) Does the electric fan come on? It has a sensor in the bottom right corner of the radiator, when facing the front of the car, that may need to be cleaned or replaced.  I replaced my water pump at the 90,000 service along with the timing belt and thermostat. At about 100,000 miles my radiator top plastic tank cracked, so I replaced it and all the hoses and installed T-Bolt clamps on all the new hoses. So my cooling system is like new. I've heard of several others radiators splitting around the same mileage, so plan on doing it in the near future. I have a new pump if yours is bad, let me know if you need it. If the engine starts to overheat while your driving turn the heat all the way up and the fan on low, of couse this will only help cool the motor if the water pump is working. How many miles are on the car?

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Turbo,

The electric fan does come on. Today, I let the car run for awhile looking for a leak or any type of drip. Nothing! Where is the coolant going? It is not in the oil. Maybe I just need a flush and fill.???? I have 107,000 miles on her. I'll check to see how the hose feels tomorrow. Thanks, again, Turbo. I'lll give you an update tomorrow.

[VGR]

The coolant might be going into your exhaust manifold and exhaust pipe if the cylinder head is cracked or the cooling passages are corroded.

What mods does your engine and car have?

[TurboGS300]

The coolant might be going into your exhaust manifold and exhaust pipe if the cylinder head is cracked or the cooling passages are corroded. 

What mods does your engine and car have?

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If that were the case he would have some white smoke <_<

[VGR]

that were the case he would have some white smoke <_<

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There would not necessarily be white smoke if the coolant leak was small due to a hairline crack in the cylinder head and a slight breach in the cylinder head gasket. kino1161 has left out alot of details like how much coolant he needs to add, how fast the coolant is lost, what the ownership & maintenance history of the car is, what mods the car / engine has. Mods = even little things like the aftermarket $5 radiator cap you suggested he buy.

[deadmilenko]

What are you topping off the radiator with? Water, TRD antifreeze, regular antifreeze? What color is the antifreeze and who makes it? Did you have a good 50/50 mix before it started dropping?

[kino1161]

What are you topping off the radiator with?  Water, TRD antifreeze, regular antifreeze?  What color is the antifreeze and who makes it?  Did you have a good 50/50 mix before it started dropping?

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First, Thanks everyone for reponding. I have no mods. :o (other than rims) I have no aftermarket radiator cap. I have no white smoke. I've had the car for about 2 years. Normal maintenance and preventive maintenenace performed, as usual. Yesterday, two of my co-workers came out and tried to see if they could find a leak anywhere with a flashlight. They found no leak. I even topped off the coolant in the overflow bottle to HIGH (because it was empty) before I left work yesterday. By late yesterday evening the overflow bottle still had the coolant inside. When it ran hot last Friday I had to put 2 gallons of water in just to get me to the Auto Store to get coolant. I put the coolant in and that lasted until this Tuesday when it ran hot again. I put almost a half bottle of 50/50 in my car then. What gives???

The 50/50 I was using was by PRESTONE. The regular coolant I was using was also PRESTONE.

[VGR]

2 gallons = 8 quarts = almost the total capacity of the entire cooling system. Any Toyota / Lexus engine will quickly overheat when operated that low on coolant. It is virtually inconceivable how a Lexus engine could lose 2 gallons of coolant without any visible signs of a leak.

When you changed the coolant originally, did you measure the amount of liquid drained and refill with an identical amount? Most do-it-yourselfers fail to do this

and end up underfilling their system which in turn causes overheating.

[TurboGS300]

If it still continues to lose coolant, pressure test the cooling system to find the leak. B)

[kino1161]

If it still continues to lose coolant, pressure test the cooling system to find the leak.  B)

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Thanks, Turbo. I was thinking about getting that done before I purchased a new radiator.

VGR, I never "changed the coolant", it ran hot.

[TWINTURBO619]

Hey what's going on, try removing your air scoop and inspect the top portion of your radiator. My car ran hot for a while and couldn't figure out why. I would do the same thing you do and still, my fluids were depleting after a while. Well I was curious into seeing what would happen if I just parked it in my driveway and let it run hot with the hood open. Well as soon as it started getting hot, I saw a very light portion of steam rising from underneath my air scoop. So I removed it and sure enough, there was a hair line crack on top of my radiator. Apparently you can't fix that so I had to purchase another one. I actually installed an IS300 radiator on my car. So try checking under the air scoop and inspect the top part of your radiator.

[TurboGS300]

Same place mine cracked, however, I saw the whisps of steam coming out over the hood as I was driving. My scoop was off, so maybe that's why? B)

[kino1161]

Thanks, guys! I'll try that!

Twin, how much did you pay for the IS radiator. Was it cheaper than for the 1st Gen GS? Thanks, again!

[TurboGS300]

Make sure the IS radiator is exactly like the GS one. So everything will bolt up and on. The GS is only $100 + shipping. I'd stick with what's designed for the car. B)

[kino1161]

Make sure the IS radiator is exactly like the GS one. So everything will bolt up and on. The GS is only $100 + shipping. I'd stick with what's designed for the car. B)

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$100 + shipping?? From where, Turbo? My local BAP GEON store has one (in stock) for $144 + tax.

[TWINTURBO619]

Make sure the IS radiator is exactly like the GS one. So everything will bolt up and on. The GS is only $100 + shipping. I'd stick with what's designed for the car. B)

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hey what's up kino. I paid a little bit over 100 bucks on my radiator. It's exactly the same as the IS300 except that it has a mounting bracket somewhere in the center because the IS300 air scoop is small. All I did was cut it off and that was that. I did everything myself. If you plan on removing your radiator, you need to be aware of a couple of things... Your fan cowl has two retaining clips that hold it together. Be careful when removing the fan cowel. Once you've removed all the bolts, don't yank the radiator just yet. At the bottom of the radiator is your trasmission cooler that have hoses attached to the bottom of your radiator (3 I think) which you need to un-do before removing your radiator. After that, it's all cake from there.

[kino1161]

Make sure the IS radiator is exactly like the GS one. So everything will bolt up and on. The GS is only $100 + shipping. I'd stick with what's designed for the car. B)

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hey what's up kino. I paid a little bit over 100 bucks on my radiator. It's exactly the same as the IS300 except that it has a mounting bracket somewhere in the center because the IS300 air scoop is small. All I did was cut it off and that was that. I did everything myself. If you plan on removing your radiator, you need to be aware of a couple of things... Your fan cowl has two retaining clips that hold it together. Be careful when removing the fan cowel. Once you've removed all the bolts, don't yank the radiator just yet. At the bottom of the radiator is your trasmission cooler that have hoses attached to the bottom of your radiator (3 I think) which you need to un-do before removing your radiator. After that, it's all cake from there.

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Hey,Thanks, Twin. From what I understand is that you don't have to remove the fan assembly to remove the radiator. Is that true? I think it was Turbo that said the radiator can be removed by taking it out from the passenger side. Also, if I am replacing my radiator does it come with the plastic "top" radiator already attached? Thanks!

[TurboGS300]

Make sure the IS radiator is exactly like the GS one. So everything will bolt up and on. The GS is only $90 + $30 shipping. I'd stick with what's designed for the car. B)

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It will take about a week to get, so decide if that's worth saving $24 + tax. B) I've already purchased one of these radiator and it is an exact fit and match to the OEM. You won't be disappointed. I wanted to get a metal one, since the plastic ones crack, however I couldn't find one that was an exact match to the OEM one. if it last another 12 to 13 years I figure it's worth it.

GS3 Radiator

[kino1161]

Make sure the IS radiator is exactly like the GS one. So everything will bolt up and on. The GS is only $90 + $30 shipping. I'd stick with what's designed for the car. B)

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It will take about a week to get, so decide if that's worth saving $24 + tax. B) I've already purchased one of these radiator and it is an exact fit and match to the OEM. You won't be disappointed. I wanted to get a metal one, since the plastic ones crack, however I couldn't find one that was an exact match to the OEM one. if it last another 12 to 13 years I figure it's worth it.

GS3 Radiator

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Thanks, Turbo! Was I correct in saying that I don't have to take the fans off to replace the radiator? Just take off the plastic scoop, unbolt and take out from the passenger side? How did you plug the transmission cooler hoses when you took out the radiator?

[chips229]

If you still cant see where the coolant is going.....pull up both floor mats in the front of the car,if the mats soaking wet then youve got a leak from the heater matrix......i had that problem with my mk1 Aristo(GS300).....

Good luck

Cheers chips.