Driving tonight on the Freeway with the top down, a guy yells to me that my car is smoking. I pulled over and found red coolant leaking vigorously onto the ground. I got back into the car and drove one more mile onto a side road and watched my temp gauge climb quickly. I pulled over and stopped before the needle hit the red mark. I then had the car towed home since I think the dealership is closed for the holiday tomorrow.

My car is a 2007 with 59,000 miles on it. I purchased it new. Anyone have any ideas as to what could have happened? Broken hose seems most likely. The car is four years old this month. Seems too new in years and mileage for this type of problem.

Anyone have a similar experience?

 

Split hose or coolant hose came loose.

Worse case would be a ruptured top plastic tank on the radiator.

 

I removed the 33 screws (agghh) that hold the plastic shield under the engine and looked for an obvious leak point but could not find one. The car has no more coolant so I know the leak is not small. Does anyone think this could be the water pump?

 

Typically when a water pump fails it isn't quite so catastrophic. It starts out as a small weep, so I doubt that the main leak is the water pump, but I wouldn't rule it out.

Also typically, coolant is green, though there may be some out there that is red. However, since your temperature did shoot way up coincidentally, it probably is your coolant.

Try taking the engine cover off from the top and looking for either wet trails or dirt trails (the moisture captures the dirt).

 

My coolant is red. There are no signs of fluid on top of the engine with the cover removed. While under the car, there are trails of fluid that resulted from the leaking last night and bouncing off the plastic shield that is now removed.

I now hear a rattling from the front of the engine while it's running. Could this be a sign of a water pump problem? It sounds like a slight knocking.

 

I also thought the coolant was green in color, but the Toyota Super Long Life Coolant is red. Direct from the owners manual - “Toyota Super Long Life Coolant” or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrate and non-borate coolant with long-life hybrid organic acid technology. “Toyota Super Long Life Coolant” is pre-mixed with 50% coolant and 50% de-ionized water."

Also, now that you mention rattling and knocking, it could be the water pump. If you replace it, I would also replace the thermostat since everything will be dismantled.

 

I read the same verbiage in the manual. Seems like some super-duper coolant, doesn't it?

Good point on the thermostat.

 

It is somewhat strange that they require certain chemical properties in the coolant, but I'd rather stay with the OEM coolant than switch to something that is not recommended. I found out the coolant was red by filling my overflow plastic tank with green coolant and than once circulated, it turned red. The green fluid that I added was so diluted with the Toyota Super Long Life coolant I chose not to flush and replace the coolant in the system.

 

Toyota manufactures their own radiator fluid, it’s a red fluid and is recommended for any Toyota or Lexus, and it’s recommended to never put traditional green anti-freeze into our systems. the two fluids do not mix well at all and will cause adverse affects


for the OP,

check all the coolant hoses, most probably you had something puncture one of the hoses causing the massive fluid loss, you have a hand full of cooling lines in the vehicle, two going from the radiator to the engine in the front of the engine and a few in the rear of the engine leading to the heater core.

 

(Quote)
for the OP,

check all the coolant hoses, most probably you had something puncture one of the hoses causing the massive fluid loss, you have a hand full of cooling lines in the vehicle, two going from the radiator to the engine in the front of the engine and a few in the rear of the engine leading to the heater core.[/QUOTE]

I checked all the lines this morning but I could not locate a failure point. It is quite possible that I could not locate the problem. The compelling part is the rattle within the front of the engine. It certainly seems like a water pump issue based on the noise I hear. Additionally, I poured 8 ounces of water in the reservoir this morning and got under the car and let it run until the needle was at the half way point. No water leaked out and the car did not overheat. I don't know how a water pump works. Can it work/fail/work again? I've since removed the 8 ounces of water from the reservoir with a turkey baster. (garage use only)

I have an Audi S5 as well and have read numerous posts from S4 owners that have had failed water pumps with coolant spewing everywhere. In the Audis, they were using a plastic water pump that had an enormously high failure rate. They have since superseded the part with a metal pump. I don't know anything about the pumps in the Lexus. I'm sure it is of higher quality than what Audi was using.

 

it could be that your water pump is bad but it would be a very rare case, I have personally never seem a Toyota Water pump fail prematurely. I've been around Toyota's all my life, and I have 200K on my land cruiser and its still on the original water pump. Toyota parts are made to last and if I remember correctly the water pump on our cars has a metal housing along with metal fins, also if your water pump did go bad then it would just fail, and wouldn't start working again randomly. 8 ounces of fluid is nothing when you area talking about your whole cooling system, and from the sound of it your system is probably bone dry, so if you simply started your car in the garage and ran it for a little the system didn't get to really do anything, you need to fill up the whole system with at least 2-3 gallons of water, then run the vehicle and see what happens. Or just take it to your local mechanic and have them check it out.

 

Check the condition of the top part of the radiator. Check to see if you can see hair line cracks. This is made of plastic and usually fails at about 7-10 years.

 

The coupe was towed via flatbed to the dealer this morning. The mystery will soon be solved.

 

Know you will keep us posted, good luck. Are you under warranty?

 

I'm one week under the four years, but 9,000 miles over the 50,000 part.

Waiting to see the problem, then will proceed with goodwill hopefully. Especially if this is the water pump which should not fail at this point.