peanut220

Hey all. My 06 IS350 has 137k on it. Decided to change the OEM radiator cap with another brand new OEM radiator cap. When I was doing so my cap came out in 3 pieces. I got the main cap, spring, and the metal band around the rubber base out. As I took the metal band out the rubber base fell and somehow disappeared into the housing area. The attached pic shows the piece I lost inside the area. Drove my car tonight with no issues.

Should I be worried? I am on my original radiator, also am bringing it to my Lexus dealer tomorrow to have them drain and fill the cooling system. Not sure if that'll do anything. I also see I am NOT the only one who has had this type of issue with OEM Toyota radiator caps....

What do you guys think?

peanut220

07blu250

]

Hello, I had the same thing happen to the cap I had. I took it off the housing and the spring was "sitting" in the housing neck. I "fished" it out, so I had the cap, the spring and a black washer like ring. But my concern is what about the other piece(s) that fell into the housing coolant? I couldn't see any other pieces, but obviously there are some because the spring was off of the cap. Any suggestions? Any issues? I would think these piece(s) would get loged into a passage or hose and cause an issue?
Thanks.

DennisMik

The pieces won't go anywhere, they will stay in the tank. The filler neck is on the inlet side of the radiator and the coolant has to go through the tubes for cooling before returning to the engine. Those pieces are too big to go through the tubes.

07blu250

Hi, Thanks for replying to me regarding the pieces of the radiator cap. So I have more info and question(s) that hopefully you can answer. When I pulled off the OEM radiator cap (vehicle has 79k milles, 2012 is250), the spring was sitting there in the filler neck, so I fished that out. I then had the cap, a black washer (that was loose and fell off the cap but not into the neck), and the spring. So basically only 3 pieces. See pics below of the 3 pieces. Looking at a NEW OEM cap (Toyota part number 16401-31650 last image below), it appears as though the black washer I'm describing above is the piece immediately below the small silver "crimp" washer. Now, here's my comments/questions (comparing the photo of the new cap to photos of existing parts): Via deduction, one can presume at least 4 parts fell into the coolant/filler neck area/system where I fished out the spring. The four parts being 1) the small silver "crimp" washer, 2) the small black O-ring immediately above the silver crimp washer, 3) the black tubular "casing" around the spring, 4) the black round "spring cap" (the one with the small hole in middle). I looked into the neck with flashlight and could not see any of these 4 parts, only the spring which I fished out. Per your reply to my initial reply to you, you said "The pieces won't go anywhere, they will stay in the tank. The filler neck is on the inlet side of the radiator and the coolant has to go through the tubes for cooling before returning to the engine. Those pieces are too big to go through the tubes." Questions: 1) My concern is that with all these pieces in the system, it may cause a blockage or issue. I really don't want to have to drain the system (the coolant is fairly new) but if need be, I will drain into clean container and put back after done. If so, where would you think these parts would be found? 2) Am I just being paranoid and should just leave it alone and not worry about it? lol

I'd appreciate you input.
Thanks!

DennisMik

If you are worried about the radiator getting blocked up, don't. You have 4 pieces and the radiator consists of hundreds of water tubes. 4 tubes, 50 tubes plugged would have such an extremely small effect on the radiator's cooling ability that you would never have a problem.

As to where the pieces are, well they are in the top tank somewhere, If the engine has run, chances are the pieces are all the way at the far end from the radiator hose, pushed there by the coolant flow. Maybe the rubber piece might float, but I don't know. If this was my car, I wouldn't worry about the pieces because you probably would have to remove the radiator and shake them out and that's too much work.

skyfox

Now this could be completely unrelated. These cars are known to have water pump failures. When I did my oil change at the dealer, they told me my radiator cap fell-apart when they were checking fluid levels and that they replaced it. Some twenty five bucks and change. No big deal. I drove home, car ran fine, and everyone was happy. Next service call comes due and I take it for an oil change after 3K miles. Dealer tells me my water pump is going bad and it is leaking all over inside of the engine compartment. Mind you I did not see any radiator fluid on my driveway, but heard whiny noises during start-up in the morning couple of days before I took it in for service. Noise only lasted for about 5 seconds in the morning and I thought it was a belt squeal due to cold temperatures. $900 later. I have a new water pump.

Could this radiator cap disintegrating have been a contributing factor?

DennisMik

I don't think your water pump failure has anything to do with the radiator cap. It is most likely just a case of unfortunate timing. If you read these forums regularly, you will see many posts about "I just had my car worked on and today my ???? broke". I don't know what it is that causes this, it certainly is strange. But in your case, you were hearing a noise so...

skyfox

Well, these cars have a high failure rate when it comes to water pumps and radiator caps failing. There is a remote possibility a connection between the two. I've had two cars that I had for over twenty five years. None of them had a disintegrating radiator cap.