Replacing radiator

[TTM]

Hi all,

I think I already did this on someone else's car but I can't remember the details - any particular recommendation when replacing the radiator on a turbo?
It looks like the oil cooler should be dropped if not taking off the metal oil line otherwise the fans and the rad itself won't drop?

Any tip welcome

 

[nick_968]

On my car (968) I always take it out of the top, first removing the spider water manifold, followed by the fan shroud, then the rad. Replace all the hoses while your in there and be very careful of the fan temp sender when you install it on the new rad as it can leak easily if you get it wrong. I know how tidy your work normally is though so I am sure you will be fine with it! Personally I never removed the oil cooler, or did it on a 944 so it might be quite different for you.

 

[TTM]

Thanks Nick.

I never looked in depth at how the front end on a 968 was made, but even though the layout looks slightly different when looked from above I always thought that the lateral frames holding the radiator were about the same?
I would be surprised if it could be taken out from the top on a 944 because of the webframe with the hood latch mechanism which is located further up front on a 968.
On a 944 I suppose it would necessarily have to "slide out" from the lateral guiding frames from the bottom...? Hazy memories here, but I would sure prefer to take it ouf from the top and I will give it a close look as it would be nice if I could avoid fiddling with the oil cooler and hoses.

Hoses are "new" (15k miles) from the engine build, and I got two seals for the fan temp sender, just in case.
(I even ordered the small plastic pipe that attaches to the radiator and links with the hose that goes to the coolant tank, as two mates broke theirs when they replace their rads, but I was surprised to find out the new rad cam with a new one already installed!)

I will also replace the turbo cooling pump as at 190k miles the original one is beginning to sound like a coffee grinder, even though it has always worked as it should.

 

[Oct]

I did mine on the lux recently, don't know if it will be different for the turbo but I removed the fan first then lifted the bottom of the rad out of the rubber bungs and slide it towards the back of the car.It should then come out from underneath.

 

[chrisg]

Hiya,

I had the radiator etc out of the 951 about two years ago and most recently the rad fad unit. Yes, to get clearance you have to disconnect both the oil pipes from the cooler and then remove the cooler.

To remove the cooler completely you have to disconnect the top feed pipe (solid pipe) - access isn't easy as the PAS cooling line get s in the way.

Once you've removed the hard pipe, you can then remove the rad fan unit, then undo all the relevant water pipes from the radiator. I seem to remember that you can do it all from underneath, BUT it's a lot easier to do some of the pipes from up top = need to remove the air intake system and the hard pipe/ support frame as well.

Good luck, feel free to ring me 07540 193874 if I can help at all,

Chris

 

[TTM]

The rad is out, without disconnecting oil lines.
I couldn't take it out from below, as the underplate can actually come out only after the rad!
One thing is for sure, this was such an orgy of coolant that I doubt the garage floor will freeze the next winter!

 

[TTM]

Almost done, just have to fill with coolant and bleed.
Looking forward to seeing if I get lower coolant temp.

 

[TTM]

So it turns out the new radiator performs just as well as the old one.
I'd have better spent the money elsewere, but maybe I can pretend it was the last "important part" that I had not replaced since the new engine [8|]
At least when I open the hood now I can see nice shiny aluminium from the top end of the radiator [8|]

 

[Mike_Pollock]

Always good to be sure!

 

[tref]

The new rad "could" be performing ten times better than the old one... is your fan running less? Assuming your coolant temperature is measured at the block where I think it is, then coolant temperature there is "controlled" by the thermostat opening and closing according to temperature... cooler water from the rad won't make any difference, unless the old rad was really knackered... will it?

 

[nick_968]

Its probably working a lot better than the old one, the cores do degrade over time and the heat exchange is not as efficient. You wouldn't really find out unless you were doing some pretty detailed monitoring or the old one was not cooling well enough to keep temps under control as things were.

 

[TTM]

I have two "problems" with my set up :
- the previous owner of the car removed the low speed resistor pack and cut the control wires
- I have a front intercooler ahead of the radiator

As a result I "think" the rad isn't cooled down as much as it should when I drive below a certain speed.

I'm not sure but apart from trying some water wetter at this point I don't know what to do to keep the temps down.

 

[nick_968]

Thats a pretty useful mod by the previous owner! Is there no way to restore it?

I never liked the way most aftermarket intercoolers for 951's have been designed with no regard for airflow to the rad. I purposefully designed my setup to replicate what is used on some of the higher powered cosworth cars running large front mount intercoolers. They mount them tight to the rad with similar height and width and an open (coarse) core designed to let as much air flow through to the rad as possible. This way I can still use all the original ducting for the rad and hopefully not detract from the water cooling. It seems to work well on the road, just need to test it out on the track.