Thicker, and yes it is.

 

New radiator installed Friday. Interesting, and frightening, thing happened when I started the car after install. The car was up on jack stands when I went to start, and immediately the loudest knocking came from the engine. I shut the car off, lowered it down, and tried again. Same noise. I was able to look in the engine compartment quickly and saw that no belts were hitting hoses, etc. Shut it off, checked all lines, made sure everything was secure, and started it again. The noise went away after half a second. It was coming from the driver side cylinder area, and the only answer I could come up with was the valve lifters were causing the noise. I don't know if it was because the oil had gravitated down to the rear of the pan and was unable to be picked up quickly enough or what. The car had been shut down for 6 days, but this has never happened before. I didn't happen again until this morning, and only lasted a split second before running normally.

Other than that, all is well with the radiator. No leaks (pressure tested after install), heater working well, etc. I did pour a bit of transmission fluid into the ports on the radiator prior to the new install, just in case. The rubber caps supplied with the new radiator helped keep it in until ready to reattach the lines.

 

Have your transmission fluid level checked by a pro, Toyota or Lexus dealer, as it's critical with WS fluid. Good call putting a little into the trans cooler on the new radiator but the level needs to be perfect.

 

I wonder if the radiator cap is better from the factory than OE today in 2020. I see the new cap all over eBay. I never woulda given a lot of thought, but this was the case with my 1998 Nissan and OE in about 2015. Not the same quality.

With my wife's car (GM SUV) I learned the radiator cap does need to work for the coolant to go back to the reservoir. I ordered the GM OE and the Gates aftermarket, and side by side, I liked Gates better (kept both installed the Gates, they looked almost identical and now I forget where they were made was not the same, GM OE was india). What was also interesting was the radiator cap was likely taken off 3-4 times in 8.5 years, prior to me taking it off another 5 times trying to figure out what was up with the level and bleeding again, it's not even accessible without removing all kinds of covering. But the o-ring was totally flattened...

 

Since you mentioned it, the transmission is shifting as smooth as it ever has. I was very careful to avoid spillage when removing the lines, and lost very little. What I did lose came from the radiator itself, which was replaced. This noise was coming directly from the driver side row of cylinders. I thought my engine was toast!

 

The new radiator did not come with a cap, so I used the cap from the original. I also have a spare I purchased prior to install thinking the original leak was coming from a loose cap.