Most likely the top seal as I can see it run all the way down to the intake box. I'm running FBO and tune. My original was replaced within two years from new, based on the previous owners maintenance history. The fan shroud came loose and melted on the radiator. This second one right now that just went out is almost 8 years old and roughly a little over 100K miles.

 

Well I joined the failed radiator crew today lol.

2011 at 80k miles and a week (to the day) since installing headers.

Besides the radiator being 9-10 years old (since 2011 technically was sold in 2010) could being FBO have been the final straw on my worn out radiator? Ive done some pulls but nothing that I figured wouldve blew out my old radiator lol. Idk im probably just being a worry wart.

Ordered a new rad/hoses/hose clamps from Bell Lexus today (it was the 1640038211 part number, so no shiny new reservoir tank lol)

 

Yeup.. Your top seal blew just like mine.. I hear its repairable but at the cost of finding the right shop and person to swap the two seals and labor.. You are at the cost of the new rad.

Also here is how you know which radiator version you have / need based on production dates.

16400 RADIATOR ASSY

16400-38210 (12/2007 - 02/2011)
16400-38211 (03/2011 - 07/2014)


16400-38H10 if you want the kit and if you have an 08, 09, 10 and some 11's with the older design.

Joe Z

 

You think any of it had to do with putting headers on? I did see slight pink staining around the clamp side of the top end tank over the past few months, figured I had at least until maybe 100k.

Just feels like coincidence that a week of having headers and my radiator goes lol.

Based on searching using my VIN, it gave me the 38211 part number, ill have to look at my buddies 08 and see if there is any visual difference I can see from the two.

I wanted to go Koyo alumin w/Hayden Transcooler but with temperatures here getting to 20-30's (and my F being a daily) just didnt want to fight with fluctuation of operating temps on the trans fluid. Plus the F may see one or two track days in the next year.

 

^^ The difference hard to see is the smaller nipple tube on the top that goes to the reservoir hose.
The newer one is larger and more robust to prevent breaking off.. The older models still running original rad will have the smaller nipple / hose = Production (12/2007 - 02/2011)


Doesn't seem the new part # is designed any better for longevity or etc..
The Top Seal is still failing after x amount of years or miles.. Nothing specific.. When it goes it goes..

Joe Z

 

Just joined the crew as well at 81k, this thread definitely helped with why the hell one model is cheaper than other, **** was pissing me off hahaahh

 

Yeah its rather annoying lol.

I just purchased new OEM radiator, upper/lower hoses, v-ribbed belt (serpentine), water pump and thermostat. Figured might as well replace those incase they decide to fail next lol

 

I noticed my 2008 IS-F with 114,600 miles had a worm clamp securing the hose from the reservoir tank to the radiator. I ordered what I thought was the correct clip (96137-41701) and a new hose (16567-38030) to get rid of that clamp. The new hose would not fit over the radiator outlet. Here is the hose that was installed and the new hose:

This lead me to this thread and the differences in the radiators. My ELE-INSP FAN/REPL SCREWS service was done at the dealer on 4/9/2015 at 55,808 miles. It does not mention anything about a new radiator. It appears I have the new style radiator which was likely replaced during the ELE campaign? While attempting to swap hoses I did notice my radiator is leaking at the seal:


I decided to go ahead and order the 16400-38H10 part number which should come with the hose and clamp I need. Ignore the temporary clamp on there, its the only one I had laying around that would fit. Total from Bell Lexus was $331.97 with free shipping.

My question to you guys, should I just put the hose (16567-38031) and correct clamp (96136-42101) in and wait a while until I want to do a transmission filter service? Will this radiator pop any day while driving? Thanks in advance!

 

Replace that radiator as soon as you can. Once it starts leaking at the tank seals, it's just a matter of time before it blows coolant all over the engine bay. So yes, it will pop any day while driving.

 

To add to an old discussion, Figs Engineering now sells an aluminum radiator with the internal trans oil heat exchanger, co-developed/made by CSF. I've also had a Koyo rad on mine for a few years now, without the internal heat exchanger, added an external trans oil cooler with improved racing thermostat, and engine oil external cooler with improved racing thermostat, stock heat exchanger retained and both trans oil and engine oil run almost the same temps from cold start to full operating temps. Driven in temps below 40F up to 90+F. And oh, oil temps (trans and engine) still go up much quicker compared to my RC F with factory oil cooling system.

 

I have the Figs radiator in my car. It works perfectly, and fits just like OEM. Zero complaints, nothing but praise for a great product.

 

You don't need an external transmission cooler? Just want to make sure I'm understanding when it is time for replacing.

 

Nope. The new Figs Competition Radiator is a fully welded/brazed design and retains the factory-style integrated transmission cooler. Too bad it was not around when my car needed a replacement. :-(

The Koyo radiator does not have an integrated transmission cooler and requires a separate core, as explained by Mike Kojima here.

 

Does anyone know if it matters which radiator hoses and clamps go with the 16400-38H10 radiator?