Lexus IS Forum banner

21 - 31 of 31 Posts

·
Super Moderator
Joined
·
19,540 Posts
Oljedi1950, it does somewhat sound like the thermostat is opening/closing prematurely. As I've said and not to beat a dead horse, but the fans should come on and stay on anytime the coolant is rising halfway or more. But since you have that much fluctuation, I'm leaning towards a thermostat, and if not that then sorry to say the WP is struggling at low rpms to move coolant. Thermostat is easy, cheap, and really would rule it down to the WP or some type of blockage.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #23
The fans do come on at the halfway point, and it doesn't appear that to be any kind of leak from the water pump.

After taking it for a ride yesterday i didn't lose any noticeable amount of coolant but i will keep watch of it.

I recently purchased Purple Ice radiator additive, it is supposed to lower engine temperatures. After putting it into the cooling system the car no longer overheats. I know this is just a band aid, but in your opinions would it be detrimental to drive the car around like this? Also do you think this rules out any possible causes for the overheating?

I still need to get in touch with a friend to use an air compressor for a leak down test.
 

·
Super Moderator
Joined
·
19,540 Posts
If both your top and bottom rad hoses get extremely hot and your fans are not coming on at the halfway point or above then your coolant temp sensor is bad. You can verify this by. Disconnecting and jumping the two pin wire harness together. They should both come on at high speed and stay on until it drops below halfway. This sensor is located right near the bottom rad hose. I'm not sure the compatibility of the additive with the toyota red coolant, so you may want to check with Lexus on that.
 

·
Super Moderator
Joined
·
19,540 Posts
Well any other coolant is ok to use as long as the system has been completely drained, filled up with distilled water, and run like that for a few days before draining and using prestone. Toyota red should really be used in our cars and will jell if mixed with any other coolant(even tho they are 95% the same, it's the 5% of additives that don't mix). Ok so the sensor/fans are good. I'm still curious if your pump is faulty and the additive is just helping.
 

·
Registered
Joined
·
471 Posts
I bled the system as everyone suggested, and took the car for a drive. After about an hour it overheated. Also it was doing fine on highway driving but shortly after i pulled into stop and go traffic it begin to overheat. Before i went for the drive the radiator was completely full and the reservoir was completely empty. Once it overheated i checked the reservoir and it was filled to the top.

Is it possible that the water pump could fail or produce less flow over an elongated drive?

Is there anyway i can test the water pump once the car is already hot?

I don't see any leaks coming from the water pump either.

As for a head gasket problem it could very well be one, the head gasket and water pump were both replaced about 2 years ago. I would just like to look into every other option before making that conclusion.

Thanks again for everyone's help.
The coolant can only go three places.

1. Through your combustion chamber
2. Leak into your oil
3. Leak between the head and block


My next question is...who repalce your head gasket? Did they use a quality gasket like felpro?

Did they use NEW torque bolts for the head? Because they are a one time type deal, they stretch.

Does the radiator look like it has a white build up inside? like minerals?

Prestone works great and Ive been using it for years.


What brand of waterpump?

If your not loosing coolant then your engine is most likely okay.

I would look into your radiator needing to replaced.
A faulty water pump
Or a bad thermostat


All in all...I would just remove the thermostat next time your car overheats.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #28
I haven't been driving the car much lately, it just started misfiring on cold start ups. The engine is giving back random cylinders, #5,6,2, and 4. After 30-60 second the car evens itself out and runs fine. I suspect it has a blown head or head gasket. I changed the oil to see what it looked like and pulled out over 5.6 quarts so coolant is getting into the oil.

I am weighing my options as to get the engine rebuilt or replaced. (It has 135,000 miles on it.) If anyone could recommend me to a shop that does quality work i would really appreciate it. I live in north New Jersey.

Thanks again for all your help.
 

·
Super Moderator
Joined
·
19,540 Posts
I would do a compression and leak down test to find out exactly what's going on. Then take it to a reputable shop. Sorry, I don't know of any shops in New Jersey, so if you get no good feedback in this forum, then i would try the North East Regional forum.
 

·
Registered
Joined
·
471 Posts
I replaced a cylinder head on my lexus and have not had any issue thus far. The thing is, you gotta do it right and buy quality parts. I used brand new head bolts from toyota, and I used an OEM headgasket. Also there is a torque pattern to get the head to seat properly that your mechanic should understand.

Im almost betting he measured the old head bolts and thought they were okay and went with them. There was another guy on here that did the same thing and had the same issues. dont need another engine, u just need whoever did the repair to do it right.

I wish i could help u because I have all the tools and know how to do the job right, u definitly dont need a new engine.
 

·
Registered
Joined
·
1 Posts
Radiator problems

So, I have to tell a story.
I live in a mountain and i have a european modell IS 250(RWD). 2006, with 165.000km with full extra and full service book so everything must be fine. But...
It is in Italy, Meran. Hot summer days and yeah the road up to the mountain to my home is 13-14km from the city.
I have this car since 2016 summer and no problem with it.
I got this job in the mountain and since from the first time my car will every time overheating if i climb the mountain.*
It is always different. Sometime it is only 110C but sometimes if outside is too hot than 130C or almost in the Red line.
I have to always turn on the heater core on full open(classic trick).
So read many many topics and videos. I checked the leaks or maybe a bad head gasket or something. But nothing...

- Changed the thermostat(the old was also fine, i have tested) - Nothing happend
- Changed the oil(i read somewhere it could be also a problem) - Nothing
- Changed the coolant - Nothing
Than i realized, the radiator cap was broken so i changed it but always yet - Nothing happend
Than i wrote a big comment in a topic somewhere and somebody said "get out the radiator and from outside or if its need than also inside wash it."
Okay, let's try...why not...
- I taked out the radiator and i got this what you see in the pictures!!
My good...i haven't seen like this before...
So, yeah 11 yeras old car, everything works fine in a normal road but on the mountain you become every little shit immediatelly.
Might be never was washed this radiator...
So i washed it. Put everything back and now works fine :)*
36C is outside. I have found a way long road up to the mountain and nothing happens :) Max 96C and than the ventilators come on for 20 second and that's all :)

So i prefer for everybody to check this out If your car is overheated!!*

And another featuer...Before i put it out i checked from the front bumper how it looks(really i must have it out or not...?) And from the front bumper it looks like clean! But not....
And another thing...the climate radiator is front of the normal radiator(picture) and the climate radiator has bigger holes than the normal one...thats why it looks clean and the thing is...it is clean!
So dont be tired. Get it out and Fuck off overheating :)

P.S.: The ventilator at working was so loud. Now are quiet :)
 
21 - 31 of 31 Posts
Top