Improving Cooling

[Outrun944]

Taking a different approach from my other topic just posted in case I end up going in circles for weeks/months (time is precious at the moment) in the 944's I've had and driven they do seem to get hot quite quickly (and I'm not driving it like a maniac!) - the current one is no exception.

I'm wondering what more can be done to improve cooling?

I'm open to all suggestions!


I see things like this for sale for the 944 on porscheshop.co.uk - http://www.porscheshop.co.uk/acatalog/2782_large.jpg
"Redline Water Wetter 355ml - Unique wetting agent reduces temperatures by upto 30F. Provides corrosion protection with just water or added with reduced Anti freeze for better heat transfer. Ideal for Race or track cars"

 

[Lowtimer]

If all your 944s have run hot, have you changed the radiator in any of them? Radiators silt up over time, and all 944s have seen the passage of a lot of time.

There's not much point improving heat transfer from the engine into the radiator if the radiator is incapable of shedding that heat effectively to the air.

 

[Outrun944]

I only owned one previously to this one (and that got hot much quicker!) - that went the way of the dodo before I even got round to less major work like radiator, etc. The other two examples are friends of mine.

The current one from memory I don't think there has been a radiator change - I haven't done one since I've owned it, I'll have to dig through the (now very) massive work/service history but I don't remember seeing it.
I take it you can flush out the radiator to clean it? And put in some better coolant?

 

[Lance]

My 944s actually runs surprisingly cool, the needle sits just of the quarter mark and only goes to just less than half sitting in traffic, I can't find any paperwork to prove a new radiator has been fitted but my engine has had a full rebuild and during the rebuild the manifold was heat wrapped all the way down the down pipe! Maybe this would reduce a lot of heat?

 

[Outrun944]

That sounds a good suggestion Lance - thanks! Would that be possible to do without dismantling engine parts?

 

[GlennS]

ORIGINAL: Lance

My 944s actually runs surprisingly cool, the needle sits just of the quarter mark and only goes to just less than half sitting in traffic, I can't find any paperwork to prove a new radiator has been fitted but my engine has had a full rebuild and during the rebuild the manifold was heat wrapped all the way down the down pipe! Maybe this would reduce a lot of heat?

Well it could be that your engine runs cool... but it is more likely that your gauge is reading incorrectly. This is a common fault.

 

[ChasR]

Or a knackered thermostat.

+1 for looking at a tired radiator. On my S2 a new rad made quite a difference (and was cited as being the reason for why I put the 3rd engine into the car (before I owned it, it's original engine had gone with the previous owner). Even on the modern when the tank started dribbling slightly, there was a marked difference in cooling. For a 944 though I can appreciate that a radiator is not cheap although the radiators from ECP are the same as the Porsche items.

Whilst I was there I would be tempted to fit a new thermostat and change any swollen hoses (this I did (I actually changed the thermostat twice!), and the hoses since many of mine were swollen) (IIRC only the heater hoses and lower hose were actually OK on my S2).

Regarding coolant, anything with the British Standard marks (I.e most good coolants) should be fine. The only thing I shall say is that to stick with the colour you have in the engine. Mixing IAT (Inorganic; 2-3 year life coolants) with OAT (5+ year life) coolants is not a great idea, although this is irrelevant if you are performing an engine flush.

 

[Lowtimer]

Flushing a radiator is not usually terribly effective. These are best regarded as lifed components and if one is furred up then it really needs replacement.

All engines are ultimately air cooled. If the radiator is not able to transfer heat effectively into the air than that is the limiting factor, and better coolant won't reduce overall temperatures.

What better coolant *is* good for is eliminating hot spots under high-stress conditions, and inhibiting corrosion long term. But if your problem is tha car heating up quickly in traffic then that's a different case from localised overheating at sustained high power. It would be a good thing to have the best coolant if you do have a new rad, as that will preserve its long-term effectiveness.

 

[barks944]

Define hot. I've seen a lot of 944's on track that haven't had any cooling issues (some have ) and cars get driven hard on track. You need to establish if you car has a reduced cooling capacity from standard. I would start by checking what the coolant temperature *actually* is. If your gauge / temperature sensor has drifted it may not be accurate any more, if it is original its 28 years old!

 

[chrisg]

Best way to improve cooling on a old car = replace the radiator and ensure the water pump is in good working order.

The problem with any radiator that is 15yrs + is not just the internal silting up with bits of rubber etc but they block up on the outside with dead flies etc. Over 10-15yrs the ability to 'dump' heat into the airflow hitting the front of the car is limited.

I found this out with my R reg Beemer - new radiator was so efficient the thermostat couldnt cope and was stuck running cool.

So, my advice for what its worth = change the radiator and if you can afford to (and be bothered) change or a least check the efficiency of the thermostat. Trust me if you only do the rad you'll notice a huge difference and ISTR that the standard 944 radiator isn't hugely expensive.

yours

Chris

 

[Outrun944]

Thanks guys! Going to go through the mass of service/work history later today and see if and when it's had a radiator change first of all

 

[Lance]

ORIGINAL: Outrun944

That sounds a good suggestion Lance - thanks! Would that be possible to do without dismantling engine parts?

I am sure my temperature gauge is working fine, the fan cuts in when queuing (half way) I think you could wrap the manifold in situ but mine is the 16v s so might be different, as to regards the heat, I can actually hold my manifold even after a long drive (very thick heat wrap fitted) so that must say something about the amount of heat build up that would normally be floating around the engine bay and I'm sure that's why mine runs a lot colder