Need help! Gas engine overheating. Cannot resolve.

Thanks @rjparker ! I had to use engine body as ground as the battery is in the trunk. The positive connection from battery is accessible from engine compartment, but not negative. Tomorrow I will try to remove battery from a different car and test it with both positive and negative from that battery, this way I will not have to use engine body as ground. I hope it works that way, don't even want to think about replacing the fan. Just so that I am clear, in my earlier test I had disconnected fan connector from original wire coming from the car battery.

 

If you have properly applied 12v directly to the fan connector it almost can not work from the normal circuit. Meaning the passenger side motor is bad.

However the back probing method for feeding power does leave a little uncertainty about the connection you made since we are not measuring separately on the downstream wires.

In a similar manner back probing the normal circuit for voltage while connected leaves significant uncertainty if you supply a separate ground.

The normal connected circuit for that motor is always grounded.

 

Thanks @rjparker ! I believe at least the passenger side fan motor is bad. This morning I did two test - connected battery from another car into back-probed 2013 Lexus CT200H radiator fan connector, the fan did not come on. Did the same connection to check 2005 Toyota Sienna XLE radiator fan and the fan worked! Below is the video of it working on 2005 Sienna and a picture of same connection on Lexus CT200H. I will try to test the other fan same way once I figure out how to back-probe or disconnect the bottom connector for driver side fan.



https://youtube.com/shorts/sX1yc7Ed_sA

 

Also, I am frustrated with gas coming out of fuel rail. Tried replacing Fuel Injectors with OEM Fuel Injectors, and now Fuel is coming out from Fuel rail. Tried re-seating fuel injectors multiple times and still the same. What did I do wrong and how can I correct this? Thanks! Below is a video clip.

https://youtube.com/shorts/pHmrf0IpoOw?feature=share

 

You will probably need a supply of new o-rings, and then to take a deep breath and look at this post, and then even this later one in that same thread.

(I do note that second post talks about using axle grease on the o-rings, which isn't any of the things Toyota suggests. Toyota suggests "spindle oil" (an obscure substance that seems hard to find in less than giant buckets), or just plain gasoline (easier to get). But then, gasoline is not famous for its slipperiness, which means being even more careful with insertion.)

 

Thank you @ChapmanF ! I definitely did not turn these left and right while installing. I am surprised that when I installed the ones from Amazon few weeks ago, that time these did not leak ... I installed those the same way. I will buy new O rings and follow your steps. Thanks again!

At one point I was thinking that the best and full-proof way to install these would be by removing the fuel rail.

 

If you have one bad fan motor it's likely both are bad. The assembly comes with both.

This aftermarket unit works well.


Four pages of thread, 6 months of your work including head gasket and a major parts cannon that would make Ukraine proud and all we are have to show is one bad water pump and one bad radiator fan. Makes that 2005 Sienna look better day by day.

 

Thanks @rjparker . I think so too! Now I just need to find a good video instruction to remove and install fan. Found below two, need to watch repeatedly ...

 

@ChapmanF : I tried again and I was very hopeful. I found spare o rings, removed all four, installed new o rings, lubed, and followed instructions you gave me. When I started the car, fuel came gushing out of fourth one on driver side. When I installed these, I felt the fourth one was slightly loose compared to others. I'm beginning to believe that the fourth hole opening somehow has gotten bigger and hence the reason. Getting tired of this, now it looks like I may need to replace the fuel line. Or maybe the best idea is to replace the engine, radiator fans, and hope for the best! Thanks again!

 

The link Chapman provided on the injectors has some specific instructions for the #4 injector which is known to be difficult.

Fuel Injectors...replacement steps.... | PriusChat
Grasshopper was a name given to a trainee in the tv show Kung Fu.

Concerning the coolant fan replacement, the Prius c video was closest, eg you take out the radiator and fans as one piece and then remove the fan assembly.

But because things are more complicated in later gens, the repair manual method takes off the front bumper cover along with parts of the air intake to get the radiator fan assembly out.

I don't believe the radiator fans will make the engine run correctly. In fact if you drive the car without ac, the radiator fans are not absolutely needed as vehicle speed pushes air through.

However if you are bound and determined to make this car right, go for it. See attached pdf.

Note on fan removal pdf: The section has an "inspection" page for the reservoir pressure cap and includes steps to remove radar sensors, both likely irrelevant to your problems.

The process is described for a gen3 Prius, not your Lexus equivalent so there could be slight differences. If you pay for a two day subscription to the Toyota TIS system (or is there a Lexus TIS system?) you can access and download specific sections of the repair manual. There is no official single doc or pdf other than some huge files individuals have pasted together. Mendel has a link to a gen3 Prius version many have. It is a mere 7595 pages that many computers can't search without crashing but some can.

 

Here is a guy who was changing his gen3 radiator but you will see him pull out the radiator and fan.

I linked the video at 36:00 for the big moment. It's not out until it's out. Wait for it.

This guy does it without taking off the bumper cover or under engine plastic. He absolutely abuses the ac condenser which would cost plenty if damaged. I would do it by the book.

 

Thanks @rjparker ! I don't think I have a choice. Either do it right or give it away. Since, like you said, 6 months of effort and all I have to show is one bad water pump and one bad radiator fan, and now fuel rail gushing fuel out ... that's sad, lol! But I got to fix the radiator fan, and after that I will look into replacing the engine and then I will hope for the best! I did couple of tests this morning, and does not look like there is coolant in any of cylinders. As @Eddie25 had suggested, I also did Q-tip test on all four cylinders, Q-tip came dry from all four ... there was a bit of dirt. Additionally I also did paper test on top of all four cylinders (covered all four cylinder holes with printer paper, had another person push gas while car was in ready mode). The paper was dry after the test from all four cylinders. Hence there does not seem to be any liquid in any of the cylinders. This car has been a nightmare for a novice like myself, and wife keeps getting upset that I've been spending too much time on garage lol ... we'll see! Thanks again!

 

You're right. Don't want to damage condensor trying to fix one part.

 

Found it, looks like entire day or two days of work for me!