C4S Radiators

I need to do some investigation as to whether I need a new radiator, in which case I'll just replace both, or whether I have a fitting that failed. but I had a small puddle under the driver's side radiator today. It looks like the C4S radiators are about double the price of C2 or C4 radiators. Anybody know why that is? Will the regular ones work? I suspect they're a little larger because of the larger openings in the bumper cover, but I couldn't figure out the real difference after doing some research this afternoon. Thanks in advance!

I am in the same boat. C4S rads are the same as the turbo, fairly pricey. I found the best price so far is from Rockauto. I have been looking also at CFS rads, it seems that both left and right are interchangeable, and are cheaper. let me know if you find something cheaper, cheers!

If you google �csf 3564,� you can find the radiators cheaper than rock auto. I didn�t look into shipping details, so maybe the total price is higher, BUT the core thicknesses is 1.25,� which is smaller than even the non-C4S radiators. If a 1.31� thick radiator can cool the same engine in a C4, I fail to see why they wouldn�t work for a C4S, but that�s a gamble. Pelican Parts has the Behr radiators for about $450 each, & they�re specifically for the C4S. A nice booty doesn�t come without a cost. 😂

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I think the CFS 3564 are for narrow body 996. it looks like 7055 is the wide body one

I agree. CSF�s website�s e-catalog specifically shows 3564 as a C4S fit, but it�s clearly wrong. It looks like it�s going to be about $900 for a pair of radiators.

https://www.design911.com/Porsche-99...3274/prod3572/ Those were the cheapest I could find and I bought & installed them in my 2003 C4S a couple of weeks ago. They were a perfect fit and good quality. I hate to say it but you just missed a January deal with 15% off (which I was lucky enough to get). This was the first time I had done it so I had some learning as I go that might help. If you are DIY, other than the pelican steps, here are some tips: - If you think there is any rust in there at all, spend a bit more and replace the fans too ($100 each from rockauto). You have to take them out anyway so it's not any extra time. Mine looked pretty bad but I didn't have replacements when I did the exchange so had to put them back in. - there are 3 hoses, 2 large & 1 small right at each radiator (supply, return, & breather). If I had it to do again I would probably replace those hoses & the clamps on them as well just for peace of mind (and I could've removed the previous ones without worrying about damaging them). - It's easier to disconnect the hoses on the side connected to the wheel well and then take them off the radiator after it is out. To disconnect/reconnect the hoses at the wheel, the solid tubes the hoses can be pulled out of the clips at the wheel base to give you more room to work with. - There are small washers to help connect to the bracket (#16 in this diagram: http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=105-15 ). A couple of mine had nearly disintegrated and I spent like 2 hour driving around trying to find a near match. They are cheap and it won't hurt to have them handy. You need 6 for each side. - The #17 clips in the diagram above are easy to remove so don't force them. You just have to lift the tab above the post and slide the clip out. You need to remove the one closest to the center of the car before you can remove the bracket with the radiator. If you have any questions, I'll try to answer. EDIT: Also, I was shocked at how bad the radiators looked at the lower back corners behind the AC condensers where crap just gets stuck and works into the radiator. I mean, they were so corroded and leaky I'm amazed I didn't have problems sooner. The connections between all the hoses were perfect. Unless someone has been disconnecting & reconnecting them a lot, I imagine it's more likely the radiators are leaking.

Thank you very much for the tips!

I would also consider the stock rads and add a 3rd (center radiator). The cooling on these cars is only a problem when you are stuck in traffic or on the track. Being stuck in traffic is a result of the fans and the airflow. Making sure enough air is moving past the front rads is how you keep the car co. Remember, your engine is only generating 10HP worth of heat. Larger radiators will not help. On the track, a 3rd radiator will probably provide the same cooling as the larger radiators for less cost.

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It's a c4s so, like the turbo, it's already got a center rad. I'm mistaken. That's only on some models.

I just ordered the radiators from Design 911 in the UK. They have a combo price for the radiators that knocks them down a bit. With shipping, it came to $570. I think that�s fair. If the idea of ordering from overseas bothers you, I found a pair from FCP Euro for $770 shipped. They claim a lifetime warranty on all their parts. Next for me is to flush my whole cooling system so that new antifreeze & old antifreeze don�t mix. Any thoughts on replacing the hoses that hook to the radiators vs just replacing the o-rings? The hoses aren�t terribly expensive, but they do add up. The hoses, themselves, seem just fine. Thanks, everyone, for your advice on this!

I think it'd depend on how much you like to work on your car and/or if you mind going back in to replace hoses later. For people using a shop, I'd be in favor of "do it while you're in there" and replace the accessible hoses, since it would avoid duplicate labor costs. If you like to DIY, it isn't your primary vehicle, and you don't mind tearing it apart again if you get a hose failure, I wouldn't bother replacing them now (in your situation, with a leak). If there was another reason for doing the work, like intermix, I'd be tempted to replace the hoses as preventative maintenance, but that isn't your situation. One other tip - a vacuum coolant filling tool is almost a necessity on these cars to get a full fill without air being trapped. The UView Airlift or similar (I have a similar tool that works well enough, but if I did it over again, I'd have bought the UView).

Figured while I was in there I'd replace the supply and return hoses and fan seeing as they're 16 years old. Bought the Schwaben coolant flush kit and had to remove the lid strut to fit it onto the reservoir. Removing the frame that holds the rad and fan together was easy leaving the ac condenser hanging. Check out Ashai's thread for a great step by step.

CFS is a good replacement, they arent very pricey and have more cooling due to design.

When I upgraded my 996.1 C2 with Turbo radiators, I bought the assemblies from Norspec Dismantling. https://norspecdismantling.com/ They are in Kent, WA. They are bigger...ask me how I know.

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This is what FSI recommends and what I am doing on my 3.8 build.

I used the CSF. They are a thing of beauty. The 40th AE, C4S and turbo all use the same radiator. Check your fan to make sure it is working. It is much easier to replace it then.

I just got a marketing email, Demonspeed is having a sale on CSF radiators. Might be worth a quick call to Ed. �CSF sponsors Demon Speed Motorsports. And Demon Speed Motorsports knows how to win with CSF. Demon Speed Motorsports won the International GT Mission Foods GT3 Cup Trophy in 2018. See us at the track in 2019. Use coupon code CSF2019 for a discount on the best replacement radiator for your Porsche�

I got the best price shipped on my csf c2 rads from renegade, the v8 swap guys. Just putting that out there if u r looking at them.

cds72911, thanks for the plug. We also have a Rennlist discount coupon code as well for these and our other parts going on right now. We have been using these on our track and cup cars for years now. Really love them. They cool great, hold up like iron, and look good doing it. https://www.demonspeedmotorsports.co...c?keywords=csf Thanks Ed

Guess i got jinxed by this thread. My 04 C4S smells like coolant from the L/F when the radiator fans come in. No signs of drips but why wait. Any body know the CSF part number for both fronts in all aluminum???

Check LN Engineering’s site.

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All the sites including LN's only list 996 carrera and another for turbo, gt2 and gt3. I assume since its a c4s it the same as the turbo?

They are the same as the turbo. 7056 and 7055 https://www.demonspeedmotorsports.co...?categoryId=-1 https://www.demonspeedmotorsports.co...?categoryId=-1 Take a look at our new product video link that we just added this week to the product page too. Thanks Ed

Those with C4S that did the 3rd Radiator, did you go with the Mezger / Turbo or the 40 Anniversary X51 radiator package? Then if so, which duct work? Looks like the Mezger 3rd is about 2 inches bigger in height and width. 99657514104 - Non Turbo or 99657514105 - Turbo Edit: Looks like its just worth going with the Turbo 3rd radiator with all associated hoses. As I suppose it appeasers no C4 or C4S had 3rd radiator and the plumbing could be a bit different?