Auxiliary Fan

[Brennie]

Hi..
Over heating problem.. I thought I’d attach a fan to the front of the radiator…
I’d like to be able to switch it on and off myself.. not thermostat controlled..
I know it’s been done before.. I’m looking at SPAL ones.. is this recommended and if so , what size and hoe does it attach please?
I see they do fitting kits that seem to push through the fins.. is this the way to go?
Thank you

[WRe]

https://www.sl113.org/forums/index.php?topic=27865.msg200623#msg200623

[roymil]

Below is a link for the electric fan option that I used.  Thermostat controlled, but could easily be manually switched if you wanted.  I also have an AC condenser so there isn't much space and this one just fit with some custom mounting work.    I assume you already have the factory fan shroud installed and 6 bladed fan, but if not, definitely try those first because they may help improve cooling more than anything because they improve the engine's fan efficiency. 

https://www.summitracing.com/parts/MAR-M113K

[rwmastel]

Brennie,

Tell us about your car.  Which model, AC installed, when/why does it overheat?  What has been done to fix the root problem?

[Brennie]

Thank you for all your help
I have a 230 SL .. it is my first W113 and I’m learning all the time.. it has always struggled in traffic.. from day one.. I was told,by the person from whom I bought the car,to just turn the heating on full blast??? I’m sure it helps a fraction but, on a scorching hot day?? Really ?
If have the early 4 blade fan and no cowl( can they be retro fitted with 280 SL fan).. the temperature climes quite significantly in the lightest of traffic and I have to pull over and let it cool down.. I thought an auxiliary fan attached to the front ( pulling or pushing??) would help.. looking at a 12inch SPAL..

[rwmastel]

Yes, an auxiliary fan will most likely help, but the 230 without AC is much less prone to overheating compared to a 280 with AC.  I don't think the Mercedes engineers designed it to overheat.  Nothing wrong with planning out a contingency, but I recommend looking for the real problem.  Are you interested in discussing that, or was that already done in a different thread?  No sense in rehashing an old discussion.

[gordon]

How much power will the fan draw ? Will the standard 35 amp alternator cope with the fan plus headlights plus wipers all drawing at the same time. I'm looking for the 80 amp alternator but can't find one in the UK.

[mdsalemi]

For what its worth, my car struggled AFTER restoration with overheating. It never actually DID overheat, but boy in summer the temperature did climb...enough that on occasion I had to stop and let things cool off.

The problem as it were, was traffic. The car did not like to idle or move in stop and go traffic at 5-10 MPH (8-15 KM/H), while it was sunny and 95F (35C) degrees outside. If I was moving, even slowly at say a constant 25 MPH (30-40 KM/H) there was no issue. If it was much lower ambient temperature, no problem either. But stop and go in the heat of summer? Big trouble.

Once, in 2002, I took the car to the "Woodward Dream Cruise" in Michigan, and I could not go very far because of these situations; I turned around and went home instead. Hundreds of old American cars also overheated in similar circumstances.

During the restoration, the restorer had sent out the radiator for "re coring". I paid not much attention. But, in 2011, the water pump had a slight leak and decided to change it. I opted (based on many recommendations here) to change from the original short pump to the long pump. I also sent out my radiator to Gerald Nisius at SL Tech in Maine, and he re-cored it again this time with a custom built core.

Never had an issue since then...

[lpeterssen]

Dear Gordon

The 35A original alternator is not enough for all those loads.

Only an electric fan for the condenser will draw a minimum of 8A, and many of them 15A

I have installed in many mercedes the Bosch AL69X which makes 80A.

Replace at least the subharness  that goes from alternator junction box to the starter to have a safe path for all that extra energy that will output from your newer alternator

This alternator mentioned above is internally regulated, so no need any more of the external voltage
regulator

The mods needed to fit are minimal

Its available in autohausaz and amazon

Best regards
Lp

[WRe]

Hi,
my experiences with the Spal suction D414-D385 T=52 / VA18-AP10//C-41A 12V were positive:
- Current consumption approx. 7A
- Running time usually only after driving for less than 1 minute (terrible, like a modern car) or at low speed and heat
- I never had problems with the battery capacity (alternator with 35A)

After the trial  I tried again without electric fan:
- Thorough cleaning (descaling) of the whole system
- Increasing the efficiency of the fan and radiator: Install fan shroud and reducing the distance between fan (original 5-blade) and radiator to a minimum (very effective)

Today everything works perfectly, although I have the impression that the viscous coupling is no longer in order (from my point of view a bad design anyway, since you need the most air pressure in situations with low speeds means low revs).
I have sold my whole electric fan equipment.
...WRe

[DaveB]

I second Rodd, a 230 shouldn’t be overheating in the UK climate. Possibly the radiator is restricted but try checking that the cap is sealing, the hoses aren’t deformed/restricted, and the thermostat is opening (or take it out temporarily). And that ignition timing is correct.

[Peter van Es]

The fan is driven by a viscous coupling. One summer a few years ago I also had overheating (drove in the heat with the heater on, yes it helps). Another tip, when stopped in traffic engage N, this helps too.

However replacing the viscous coupling on the fan drive resolved all my issues. Drove this Saturday in 35°C, no issues at all.

Peter

[rwmastel]

The fan is driven by a viscous coupling.

Not on a 230SL.  It is fixed to the water pump.

Let's summarize.

It seems that to get a cooling system into a healthy baseline state one should:
- Pressure test the coolant system
- Chemical descale the coolant system
- Check effectiveness of water pump (not sure how)
- Check effectiveness of fan viscous coupling (if so equipped)
- Check effectiveness of thermostat (in a pot on the stove, with thermometer)
- Check effectiveness of radiator (thermo imaging looking for cool spots)
- Ensure car is not running lean
 -- fix anything found faulty in above tests

If the car still runs hot, then modifications/upgrades can include:
- Replace thermostat with one that opens at cooler temp
- Install a fan with more blades
- Install a supplemental electric fan
- Position the radiator closer to the fan (its adjustable)
- Install a fan shroud if one is not installed
- Install a heater core bypass hose
- Recore radiator, upgrading from two row to three row system
- Install a "long water pump" if engine currently has a short water pump

What have I missed?

[WRe]

- Position the fan closer to the radiator (not sure how)
- Install a heater core bypass hose

Hi,
Good roundup Rodd!

- Position of the radiator is changeable.
- I had a heater bypass installed but could not recognize any progress
...WRe

[rwmastel]

Oh, I was thinking backwards!     I updated the list item to reflect clear thinking.

I was wondering what's the difference between the long and short water pumps, and it appears it's just the length of the shaft that the fan mounts to.  The short pump requires a spacer to put the fan pully in the right place, and the long pump just puts it in place by itself.  I thought there might be some water flow dynamics that were different, but the differences appear to be just external.

[rwmastel]

Brennie,

Did you decide to move forward with a specific electric fan solution, or are you working through some of the corrective measures?

[Brennie]

I haven’t settled on a fan yet..
I need more information
Do I need a 12inch one( bigger the better?)
If installed in the front of the radiator.. should it blow or suck?
Even in light traffic the other day the temperature rose dramatically.. drops as soon as there is open road.. it makes me nervous.. I don’t want to damage the engine… it’s also done this since I’ve owned the car..
I plan to have the radiator seen to and struggling to get an answer to the question.. can I just swap the original 4 blade fan for a 6 or 9 blade one? Is it plug and play or are they totally incompatible with M127 engines and only for later models?

[dirkbalter]

As a suggestion, if you decide to to put the auxiliary fan in front of the radiator, make sure you clear the hood as it opens.

The 230 air cleaner shroud is bigger the the 250/280. Although there are fans out there from other cars or special orders at the time, the typical advertised multi blade replacement fan is to big. The fan is also bolted to a viscous clutch which requires a different water pump with a different bolt pattern.
I did the conversion above and cut the wings off the fan by approx. 3/4" to clear the interferences. I found that out as I was installing the components. If I would have known, I probably would have stuck to the original 230 set up.   
 
 

[rwmastel]

It seems that to get a cooling system into a healthy baseline state one should:
- Pressure test the coolant system
- Chemical descale the coolant system
- Check effectiveness of water pump (not sure how)
- Check effectiveness of thermostat (in a pot on the stove, with thermometer)
- Check effectiveness of radiator (thermo imaging looking for cool spots)
- Ensure car is not running lean
 -- fix anything found faulty in above tests

Brennie,

Hi.  Do you know how much, if any, of the above has been done by you or previous owner?  It's always nice to start with a good baseline, knowing for sure what is good and what needs help.  No guessing or assuming.