Fitting a new radiator, any tips?

Hi all, Im planning to fit a new rad (drivers side) to my 996, Ive got the bumper and ducts off, and it 'looks' straight foward, but is there anything to look out for? and tips for a smooth, easy fit?

Fit new rad pipes :thumb:

I replaced my own radiator as well. I chose to keep the existing hoses as they looked and felt fine. It probably isn't a bad idea to replace them for extra reassurance, especially after all the dismantling done. There is nothing too complicated except its a bit fiddly getting the hoses on when you've got the new radiator on. Also be careful with the clips holding the fan to the radiator as they are a bit fragile if rusted. When re-installing the radiator and fan assembly back in be careful with the aircon condensor getting in the way and crushing the fins of either that or the radiator. I put a small bit of cardboard over the condensor to protect it. When refilling the coolant, keep the small vent hose off the radiator and SLOWLY fill the coolant tank. As the car is jacked up the front you should find that most of the air purges via the vent hole. Only when there is a steady stream of coolant emerging from the vent hole that you then connect it up. What I did then was start the engine as I started tidying things away and you'll find the engine would be fairly near operating temperature by then to check for leaks. I kept the engine running as I reinstalled the front PU so by then things were pretty warm and you can have a look about again for leaks. I was lucky and had no air locks and filled it with exactly the amount that came out. I used fresh 50% coolant mix so you need about 3 liters of the mix (1.5 liters of coolant) although that was for the passenger side radiator. Good luck. Min

Min, cheers for that write-up. Only 3L in total to top up? is that all you loose when you take the old rad off? (well there abouts)

That is what drained from the passenger side. Given the complicated run of the hoses it may be more or less on the driver's side. I've just checked, I bought 4 liters of Porsche coolant and I still have 2 and half bottles so that is right. If you want to save cost, any Glysantin G30 containing coolant is safe to use. BASF makes the Glysantin additive that forms an important part of the corrosion inhibitor package. Mobil or Comma make the said coolants and they will be cheaper than the Porsche one. If you car is like mine then the original coolant is yellowish in colour. The later pink stuff is compatible with it. Here is a bit about coolants I wrote another time : The original coolant in your car (yellowish) is an Organic Acid (OAT) type. These are known as silicate-free coolants. They are supposed to last for life. Older blue coolants had to be replaced as they contained silicates that get used up over time. The later pink/red coolants are a newer technology called Hybrid Organic Acid (HOAT) which is actually an OAT coolant with some type of silicate. The are also supposed to last the lifetime of the car. You are not supposed to mix any OAT/HOAT coolants with the older silicate type as you end up with this brown sludge in you system. However the newer HOAT ones can be added to OAT coolants hence the new Porsche pink coolant can be added to the older yellowish coolant in the older 996s.

Great stuff, mine is the yellow type to, Thank you for your help, Ill let you know how it goes.

Hi chaps, well I changed the rad, bit of a fiddle, but got there. A mate of mine, (ex BMW mechanic ) said I could top up with comma G48 (Which is blue) but is an OAT type of coolant, would this go with my original yellow coolant??

Not the G48. Its the Comma G30 silicate-free OAT one you need.

Cheers, thanks again for all you help Min. :thumb:

Right hand radiator on my turbo has thrown the towel in. Last time a had the bumper off I couldn't really see how you get at the hoses with the rads in place? I'd tackle it myself if I can understand what needs to be done. Anything you can tell me? Thanks.

You also have to remove the wheel arch trim. That is not hard to do. After that it is a bit fiddly but it is a matter of getting your hand in to remove the clips then the hoses. Just a point of note, to bleed the system after on the Turbo you are supposed to have the car connected to the PST or PIWIS system.

Thanks for that. I replaced the wheel liner on the other side last summer so know how to do that. Do the hoseclips just pull out? I see in the workshop manual it talks about a tool that can be used. Final question - Does a durametric have the required feature for bleeding the system? (Excuse to buy one if it does!)

Hi Min, Any tips on draining/refilling/bleeding the coolant system? even thou ive heard the coolant lasts the life of the car (which I dont agree on, Comma OAT lasts 5 years) id like to do a full flush out at some point, cheers in advance. PS the new rad is on and working well. :wink:

The clips can be undone with a pair of normal pliers or waterpump pliers. I have the special hoseclip tool which makes it just slightly easier as it is on a ratchet. They only cost about £5 and you can get it from any motor factors. Sealey and Draper do them I don't know if the Durametric does the special bleeding procedure. PM Richard Hamilton on this forum and he will know. In response to idp - With regards to the lifetime coolant, I can't say if it will definitely last a lifetime as the OAT component is not meant to be used up unlike the old silicates. Still it can probably oxidise overtime. Only a chemical engineer can confirm or refute this. I also replaced the coolant tank on my car so in all I've probably replaced about 12 litres of coolant in all including the radiator change so that will probably top up the additive package. You are like me liking the reassurance of fresh fluid in the system. The only thing is if you drain the whole system it can be a PITA to get the air out properly. I'm glad everything went smoothly. It is quite rewarding to do.

Would this do it? 1, drain coolant from the coolant plug (under engine) 2, take the bottom pipes off the 2 rads 3, take overflow hoses off rads 4, flush through with clean water 5, put coolant plug and bottom pipes back on 6, fill with 10L of water, then add 3L of Comma G30, add more water till it comes out of the overflow 7, replace overflow hoses 8, top up as needed Or would you still not recommend draining the whole system?