Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Do Toyota Factory Radiators have a Date Stamp?

I have a 2006 Toyota Highlander Hybrid. I had the dealership replace the radiator with a factory part in June of 2014, and I just had to have it replaced again on 1/28/16. I commented to my mechanic that it was strange that the radiator wouldn’t even last 18 months. He stated that due to the buildup on the radiator and the foam packing that the radiator was original to the car. I took the old radiator back to the dealership, and they are claiming that there is a date stamp on the replacement radiator that proves it was replaced. My question is, is there a date stamp on a Toyota factory radiator, and if so, where is it located?

Why not ask the dealership that claims there is one to explain, or better yet show, you where it is?

Most parts now have bar codes and other identifying labels on them that are designed to withstand many years exposure to the elements.

You do realize that Toyota like other vehicle manufacturers don’t make their own radiators?

They’re purchased from a supplier/vendor.

So there may be a date code on the radiator. But the manufacturer of the radiator would know if there is and how it’s coded.


Anytime anybody makes a claim that you find questionable, you should feel comfortable politely saying “show me” right at the time they make the statement. It’s your money at stake.

I wish more people would. People tend to feel intimidated, but they shouldn’t.

Thank you for the responses. I did ask him to show me the “date stamp”. There were the numbers 1-13 at the top of the radiator. What I don’t know is if that is a date or another marking. The mechanic I go to now is adamant that the buildup on the radiator could not have happened in a 15 month period. Just wondering if anyone out there knows for sure whether whoever supplies Toyota factory replacement radiators date stamps them.

If that 1-13 is a date stamp, it would indicate the radiator was manufactured in January, 2013.


Toyota is an ISO9000 certified company and as part of that certification, they only buy parts from other ISO9000 certified companies. ISO certification requires traceability so yes, the radiator would have a date stamp. It probably has a shift stamp as well.

Not only the radiator, but each of its components would have a date on them. The plastic tanks usually have a clock like symbol in the mold that is updated every day with the current date/shift and mold number.

If any part has a date of 2013, then it would have to have been made on or after that date.

If it is a molded number 1-13, that looks more like a mold number.

I’m wondering what the radiator was clogged with.

When the original radiator had its problem, did you perchance use some form of additive?
What was the original problem, a leak or an overheating problem?
Was there any diagnosis done originally, or did you just say “change the radiator” on the assumption that it was the problem?
What was the second problem that suggested that the radiator was plugged? Was a flow test done?

What I’m getting at is, I’m wondering if the original problem was overheating and it was a failing headgasket rather than a bad radiator.
I’m also wondering if the original problem was leaking and you tried a few bottles of “stop leak” or even ground pepper to try to seal it… and the engine didn’t get flushed of it when the new radiator was installed.

Post back.

I don’t know how to date the radiator, but for radiators that seem to not last very long I’m always suspicious that there’s an unwanted current path going through the radiator. That creates a chemical reaction that can quickly dissolve metal inside the radiator and cause it to leak prematurely. Upon installing a new one, ask your shop to make sure the radiator is mounted properly. There are various isolation gadgets where the radiator mounts to the chassis, so make sure those are all present and accounted for. And that no wires or connectors are resting against the radiator, especially look in the area of the radiator fan for unwanted current paths. I’d guess it is possible for a shop to detect currents flowing through the radiator with an amp meter, but not sure how, as I’ve never done it myself. Also make sure the coolant meets Toyota’s specs, as it is part of what protects the radiator. Contamination of the cooling system can cause this too. For example if there’s exhaust gasses getting into the coolant, it will make the coolant acidic and acidic coolant will conduct electricity while new coolant won’t. Ask your shop to measure the pH of the coolant.


I have my aluminum foil helmet on my head at this very moment!


Ground straps were used on brass heater cores to prevent electrolysis but with an aluminium engine and aluminium radiator I don’t think that is a problem.

The Art of the Guess , By George …lol

My Corolla model year had this problem, which was discovered by Toyota, and it is described and what to do about it in the associated Technical Service Bulletin

Galvanic corrosion would also be a problem with aluminum.
And that’s an excellent piece of input. I’ve taken the liberty of providing a link to numerous websites addressing the subject.
Hopefully one of them will help you.

Good links there TSM. Googling “Radiator Electrolysis” will also bring up a bevy of info. For example:

"Electrolysis is the result of electricity flowing through your cooling system and causing an electrochemical charge across the aluminum. This results in rapid corrosion and severe damage to the components in your cooling system including discoloration, pitting, flaking, and pinholes. Most common in late model vehicles ..."

I hope the OP posts back. I’d like to help and I’m wondering if we might be onto something here.

Thank you for all of the comments and suggestions. No, I did not use any additives. Don’t know if anything was clogging the radiator or not. It was my wife’s car, and one day as she was driving it a warning light saying “Check Hybrid System” came on. She turned around and started to head to the dealership, and it died on the highway with her and my daughter in it. We had is towed to the dealership, and they stated that it needed a new radiator. My wife says it did not overheat before it quit running. I did question why the radiator would cause that warning, but my dad was put in hospice that day and I honestly can’t remember what they told me. The dealership did not return the old radiator to me. Recently, the car started making a low rumbling sound when the AC was on. As the dealership had replaced the AC blower motor less than a year ago, I took it back to them. They said the blower motor was fine, but that I needed a new cooling fan assembly and radiator. The radiator was leaking from the plastic tanks on the side, so I don’t know if the electrostatic issues mentioned were the culprit.

I took the car to a new mechanic that was vouched for by friends, and he insists that the radiator was never replaced. He states that the build up of debris could not have happened in 18 months, and that there is foam on the radiator that is only put on in the factory. The dealership says that a marking of 1-13 on the aluminum part of the radiator is a date stamp. My question is, does anyone know what date stamp looks like or where it might be located on the radiator? I think the dealership charged me for work that was not done, and that they are now lying to CYA. Thanks for any help you can provide.

If the radiator was leaking from the rubber side seals, I’m inclined to agree with your mechanic now. Those are usually good for at least 10 years. But to be honest, I would have to look at the radiator for myself to really judge.

In the first picture there are tree radiators, the date code is below the part number; 8F, 9D and 1K. The digit is the year and the letter is the month, D representing the fourth month and F the sixth. These are the original radiators, I don’t remember what the date code looks like on the replacements.

All Toyota replacement radiators come with foam around the sides just like the original. After ten years the foam crumbles when touched and is impossible to handle without falling apart, see the third picture.

That’s very interesting. Do you know how you would tell if the 1K was 2001 or 2011? Here are the markings on the radiator I just had replaced. The 1-13 is what the dealer claims is the date stamp. The 4H would indicate a radiator made in August? The car is a 2006, and the radiator was supposedly replaced in June 2014. Thank you everyone for the help!!!

4H is either August 2014 or August 2004. Since the radiator was replaced in June 2014, the date stamp has to be August 2004. This assumes that the replacement radiator uses the same date code designation. It is in the same spot, and the other stamps are similar to the ones that @Nevada_545 posted.