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2004 OEM radiator is failing. How long do I have to replace?

9K views 37 replies 10 participants last post by  dttruax 
#1 · (Edited)
2004 OEM radiator is failing. I have the Koyo to install.

It was fine earlier this week. :unhappy: The seal all along the top tank has started to leak. Did not smell coolant all day after driving nearly 100 miles. I need to do another 100 miles tomorrow. Bad idea? Take along some water? Have a tow truck follow me (not really)?

What is the best all aluminum replacement? Koyo?

This is the darker green Subaru coolant ooze:

 
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#2 ·
It was fine earlier this week. :unhappy: The seal all along the top tank has started to leak. Did not smell coolant all day after driving nearly 100 miles. I need to do another 100 miles tomorrow. Bad idea?
It looks to me to be the early stages, I would feel fairly comfortable driving another 100 miles

Take along some water?
Absolutely

Have a tow truck follow me (not really)?
Do you have one on retainer :)
 
#3 · (Edited)
Hi Sasquatch!

Sorry about the juicy rad. I've had two fail so far. That is a lot of fluid loss though... I'd be worried about driving 100 mi and would consider renting a car instead if need be.

I do not use the all-Al rad; I use an OEM replacement instead. This means my third rad looks just like yours, or like my second or first. However, the rad I bought is not (NOT!) a Calsonic (the brand SOA uses). It is a Koyo.

I rang up Koyo and spoke to someone very helpful. He told me they make both an OEM style and a "race" all-Al. I have been pleased with my OEM style Koyo and would not hesitate to use their products, based not just on the fit of the part I bought but also because of my tendency to "buy" the maker and/or vendor, not just the part.

I am aware that the Koyo all-Al rads cost more than CX or CRX or however they're spelled, and more than Mishimoto, but I think it's a quality brand for what it's worth. (A friend with the Csomething rad in his Acura had the drain plug leak on arrival and had to source another one etc. The welds look good on it though.)

(For those with automatic transmissions: the OEM radiator has a separate cooler for transmission fluid, and the Koyo OEM replacement also has this -- so if you have a manual, just ignore the fittings like I have -- but the "race" all-Al apparently does not, so you have to ask and verify this, and if so, figure out a transmission fluid cooler in addition to the Al rad).

I bought my Koyo from a local radiator shop.

SD

For your coast:
Koyo
390 Starke Road Unit2 Carlstadt,
NJ 07072, U.S.A.
Tel: +1-201-896-6676
Fax: +1-201-896-6650
Toll Free: +1-877-896-6676
E-mail: sales@koyorad.com

For my coast:
Koyo
15 Doppler Irvine, CA 92618,
U.S.A.
Tel: +1-949-727-7054
Fax: +1-949-727-7445(Sales)
+1-949-727-3629(Administration)
E-mail: sales@koyorad.com

They should be able to confirm the correct part number for your -- or any -- application and provide a list of local vendors should you need the rad ASAP.
 
#4 ·
Thanks Spiros. I would think an all aluminum would be best, no?

My neighbor is an automotive tech for a dealer. He seems to think I'd be OK with this one for a time. I had a Ford Probe in the last century that did the same thing twice. As I recall I had a couple of weeks to replace them.
 
#5 ·
The all-Al seems like a more durable, attractive option, yes, and since you autox routinely you could always use some extra capacity I suppose. The Koyo OEMs are about 1/2 to 1/3 the cost of the Koyo Al rads though, so my choice was made for me. If you have the $ I don't see why not to go Al, just be aware that you may have to trim the hoses to get a good fit (I don't know for sure). Also be ready to use different screws for the cooling fans if need be.

There is also Fluidyne but I've never had one and the all-Al version is well over $500 I think, so more expensive than the Koyo.
 
#6 ·
The all-Al seems like a more durable, attractive option, yes, and since you autox routinely you could always use some extra capacity I suppose. The Koyo OEMs are about 1/2 to 1/3 the cost of the Koyo Al rads though, so my choice was made for me. If you have the $ I don't see why not to go Al, just be aware that you may have to trim the hoses to get a good fit (I don't know for sure). Also be ready to use different screws for the cooling fans if need be.
OK, thanks as always. :)
 
#10 ·
I've seen them on other WRXs and my impressions were good. Seeing the entire piece will be nice, although I wish the circumstances were a bit different. :/
 
#13 ·
Silver lining...a broken part is always a good excuse to upgrade to performance aftermarket :cool:
 
#14 ·
I suppose. From what I have read here and elsewhere I knew it was only a matter of time before the OEM failed. The timing could have been better (the wheel powdercoat issue). :rolleyes:
 
#15 ·
I got the Koyo yesterday. Looks nice ... :) One more under hood item to keep OCD shiny. Gorgeous welds. Super light weight. I hope it all fits nice.

Saturday is install day: Partly sunny, with a high near 38. North wind between 5 and 7 mph. Brrr ...





 
#17 ·
Before the car comes apart it might be worthwhile to check and see that the threads for the bolts that mount the fans match what you've got already. Otherwise get the bolts beforehand. There are also a couple lines that connect to the rad up top toward the steering pump side, so you might check those too.
 
#19 · (Edited)
Let me know how it goes, Bill. I remember reading that the Koyo All-Al radiators had trouble clearing the bottom bumper bracket when installed in Bugeyes. I don't know if that's the current design or if it has the same issue with the blobeyes...
Thanks for the heads up guys. :)

Update: OEM fan screws - sheet metal / plastic threads. Koyo - standard threads. I'm off to get the right bolts.
 
#18 ·
Let me know how it goes, Bill. I remember reading that the Koyo All-Al radiators had trouble clearing the bottom bumper bracket when installed in Bugeyes. I don't know if that's the current design or if it has the same issue with the blobeyes...
 
#20 · (Edited)
Installed the Koyo today. The fit was mostly good, with a couple of minor issues. First was one of the fans was misaligned by a millimeter or two. A little side of drill bit action to enlarge the fan mounting frame holes was all that was needed.

Once the radiator was seated it was not quite parallel with the car. The end makes contact on the passenger side, but nowhere else. I added a piece of hard rubber to prevent metal to metal contact (bottom image). I plan on driving it a bit, and then loosen everything and see if it seats any better.

It appears as though I did not fully burp the system as temps rose above normal during a test drive. I'll try again tomorrow.

I also plan on getting some silicone hoses sooner than later and a new thermostat for good measure. It would have been nice if I had them today. I'm thinking the best replacement thermostat is OEM - any opinions (SD_GR, brfatal)?



 
#21 · (Edited)
I just did my timing belt and went with an authentic Subaru Tstat because the old one was still working great and they are cheaper than the fancy stats. I also used a Suaru gasket. Be careful not to overtighten the bolts. I looked up the spec and used a torque wrench to be certain.

If you are coming up on tbelt service time you may as well do the hoses and stat with the water pump to save yourself the trouble plus a gasket maybe?
 
#25 ·
Is there any negative effect of going from a 180-190* running temp to a 160-170* running temp?
 
#26 ·
Not so sure. The claim made here is appealing: GrimmSpeed

"Many OEM style T-Stats can have a very negative effect on your vehicle, if they fail, they fail closed and your car will overheat. But not ours! If there is a failure with our T-Stat, it will fail in the OPEN position allowing coolant to flow and keep your engine temps under control".

Is this for real? :confused:
 
#30 ·
About the metal-to-metal contact. If it's only on the top where the photo shows the piece of rubber, and the rad doesn't settle when you check it next time as you said, could you use a modified retainer bracket? The one from Subaru has a fixed screw hole on the car side and a "wobble" fitting (I don't know how to say it) on the rad side, and it only bolts onto the car side. Could you grab a spare bracket and experiment with a different hole placement? Just throwing out ideas.
 
#31 · (Edited)
could you use a modified retainer bracket? The one from Subaru has a fixed screw hole on the car side and a "wobble" fitting (I don't know how to say it) on the rad side, and it only bolts onto the car side. Could you grab a spare bracket and experiment with a different hole placement? Just throwing out ideas.
What is this modified retainer bracket? I'm not familiar with it.

I did not realize it until yesterday :confused: the Koyo core is substantially thicker than OEM.

Edit: I just measured them; OEM = 27mm, Koyo = 53mm.
 
#36 ·
The OEM thermostat seems to fail closed, at least according to the makers of a replacement thermostat designed to fail open (and also designed to cost... $70, which is why I never bought one and never will). I've not heard about that T-stat in years though, don't know if they are still around.
 
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