Has anyone else had a KOYO radiator fail?

[rakkasan]

I'm a little ticked, my KOYO failed. I took it to have it repaired, but it was so bad, it would cost as much as a replacement.

When submersed and pressurized to 20psi, we counted at least 4 leaks on top and three on the bottom, all on the inner cores where they enter the tanks. No damage has been done to the radiator, so it's more than likely a manufacturers defect.

Before you ask, KOYO isn't going to comp it. I've had it for 2 years, their warranty is for 1.5 years.....

 

[suprahero]

Mine is holding strong after two and a half years Mark. I hate to hear that, but at least you know it's not the waterpump now. The radiator costs more, but it's a hell of a lot easier to install also.

 

[tissimo]

I dont see how it could fail unless there was an outside problem that caused the endtank to fail (I'm assuming where the core was welded to the endtank is where its leaking?).

If it was a manufacture defect it would of been leaking from the get go.

 

[adampecush]

any contact between the radiator and the car body by any chance?

This reeks of galvanic corrosion...

 

[rakkasan]

Mine is holding strong after two and a half years Mark. I hate to hear that, but at least you know it's not the waterpump now. The radiator costs more, but it's a hell of a lot easier to install also.

I bought a reman'd hydro pump from Aaron regardless, it will go on my 1.5J when I get it going..

I dont see how it could fail unless there was an outside problem that caused the endtank to fail (I'm assuming where the core was welded to the endtank is where its leaking?).

If it was a manufacture defect it would of been leaking from the get go.

I've had a slow leak since the swap, but I thought it was from using the factory hose clamps (which I think was partially correct). As soon as I swapped the factory clamps for worm drive clamps, the radiator took a BIG shit. I think that the increased pressure after swapping clamps turned small holes into big ones.

any contact between the radiator and the car body by any chance?

This reeks of galvanic corrosion...

No, no contact. However, the radiator guy said that he's had a few KOYOs fail. After trying to collect on the warranty, 1-800-RADIATOR (his supplier) said no. They said that it could be caused by bad motor grounds; arching from the motor-to-radiator causes electrolysis ?!?

 

[lagged]

check for contact as previously stated, and dont forget to check the radiator mounts them selves.

i am pretty sure that the rubber mounts are there to insulate against galvanic corrosion.

 

[IJ.]

"Stray Current"

 

[MKIIINA]

we have quite a few guys here in the dfw area running the koyos without a problem (my brother and myself included for the past 2 years). I did notice there is a difference between some of the newer ones and the older ones in regards to the stamping on the top end tank but didnt check the bottoms and really didnt think much of it at the time. glad you found the problem but sucks it was a koyo

 

[rakkasan]

check for contact as previously stated, and dont forget to check the radiator mounts them selves.

i am pretty sure that the rubber mounts are there to insulate against galvanic corrosion.

There is no contact

 

[Poodles]

we have quite a few guys here in the dfw area running the koyos without a problem (my brother and myself included for the past 2 years). I did notice there is a difference between some of the newer ones and the older ones in regards to the stamping on the top end tank but didnt check the bottoms and really didnt think much of it at the time. glad you found the problem but sucks it was a koyo

Me too :wave:

Zero issues, but I agree with the rest, sounds like an erosion problem...

 

[zoonwen]

Had a friend who had one fail because the previous owner only ran water through it.

 

[tekdeus]

I just tested the resistance in my Koyo rad to ground. 0.9 ohms. Is this normal?

 

[IJ.]

Look for voltage and it needs to be an anologue multi meter NOT a Digi.

 

[rakkasan]

Look for voltage and it needs to be an anologue multi meter NOT a Digi.

I'll have to check it as discribed after I get a new radiator.

 

[adampecush]

I just tested the resistance in my Koyo rad to ground. 0.9 ohms. Is this normal?

turn your multimeter to mV, put one lead in the coolant (not touching the rad) and one on the (-) terminal. If the reading is higher than about 40-50mV, you've got a problem. Diagnose from there (ensure all grounds are present and functional, etc) and you will probably want to change the coolant when you are finished.

 

[adampecush]

Had a friend who had one fail because the previous owner only ran water through it.

if it was tap water, yeah, that would probably be why.

if it was distilled water, the problem was elsewhere. (distilled water = non-conductive)

 

[tekdeus]

A little off topic, but I was forced to take my car to a small town shop in Nevada when my timing belt & pulley needed replacing on the way to Vegas. The mechanic topped up my Toyota red coolant with some other type of domestic red coolant and said that they are compatible. Is this true?

 

[jdub]

some other type of domestic red coolant

Doesn't tell us a whole lot without knowing the brand/type...frankly, an impossible question to answer.

 

[IJ.]

I'll have to check it as discribed after I get a new radiator.

A good place to start "fixing" it is if the car has had any body work done check the grounds in that area.

 

[rakkasan]

A good place to start "fixing" it is if the car has had any body work done check the grounds in that area.

Will do. There hasn't been any bodywork done, although it was painted almost two years ago.

As Jay will attest, my motor is well grounded. I have two 0 gauge stainless steel military grade ground straps :naughty:.