M119.971 radiator and fan opinions

[guyonabuffalo]

Hi folks, have any of you tried installing the Nissens 85151 electric fan on your M119 engine? My viscous fan clutch is bad and I am considering tackling the cooling system. Last summer, I had a few moments in heavy traffic where the temp gauge went into the brown pants range. I really don't want that happening again.

I have used a Nissens radiator on my previous w140 (300SD) and it worked really well. So, I am thinking of getting the same (Nissens 62716A). The fan clutch definitely needs replacing but I found the Nissens 85151 fan as a recommendation along with that radiator. These look like the smaller electric fan thats in the front of the radiator. Can someone verify this?

On that note, I was hoping to convert the viscous fan to an electric setup as some folks on this forum seem to have gotten good results by doing this. However; I dont know if I want to add an external electrical connection. Any thoughts on whether going the electric fan route is worth it or not?

 

[JC220]

The elecrric fan route is not worth it. The only fan that would stand a chance to reliably cool an m119 is a factory pcm fan from another Mercedes model with custom cowling and complicated control electronics.

Replace your original viscous clutch is the best option. Having experience from adding 2x electric fans on my 500E with custom cowling it just struggled big time even in Irish ambient temps!

 

[gsxr]

Nissens 85151 appears to be a replacement for one of the twin auxiliary fans ahead of the condenser. This is far smaller than the mechanical fan. Assuming you are looking into a primary replacement for the mechanical fan+clutch, the Nissens 85151 will absolutely not work, full stop.

Pretty much any aftermarket electric fan also will not work as well as the mechanical fan+clutch. Most cannot move enough air, and/or they are too loud, and none have a shroud that will cover the entire radiator core.

JC220 is correct, the only possible option is a factory Mercedes fan used on a mid-2000's model year, of the appropriate size / dimensions. This will require significant modification of the shroud to install, along with custom fabricated mounting bracketry. Clearance to the pulleys may be very tight. Then you need to get a custom PWM controller. This setup can work very, very well and is superior to the mechanical fan - but it's a LOT of work (and $$$) to do it right.

This thread goes into detail about fan options and is required reading if you want to pursue the conversion. The late-model factory fan & PWM controller discussion begins around post #68. Skip to post #81 to see the factory fan being discussed. Controller options are outlined in post #106.

 

[guyonabuffalo]

Thanks, @JC220 and @gsxr. I did read through those posts last night and was hoping that by now somebody would have found and or produced a better plug and play electric fan conversion setup. Oh well.

I was originally planning on doing the fan clutch first anyway - so I will stay the course on that. I remember the fan clutch replacement on my 300SD was not all that fun for my knuckles, so I m sure this time will be the same or possibly worse. Just ordered the fan clutch. Fingers crossed and knuckles bandaged.

Also, just so I am 100% certain that this is the right move - I am able to stop the fan from moving when the engine is running - by hand (I used a piece of rubber and not my fingers directly). This is an indication that the fan clutch is busted, right? This and the fact that in heavy traffic, it can get pretty toasty even in Canadian winter.

 

[gsxr]

Thanks, @JC220 and @gsxr. I did read through those posts last night and was hoping that by now somebody would have found and or produced a better plug and play electric fan conversion setup. Oh well.

There's no plug+play solution, but if you aren't afraid to wield a Dremel and oscillating tool, it sure looks like the 204 fan can be made to fit pretty well. Use the Microauotonomations v3 controller. This setup should be vastly superior to the mechanical fan. I'd also upgrade to a 150A alternator to feed the fan.

I was originally planning on doing the fan clutch first anyway - so I will stay the course on that. I remember the fan clutch replacement on my 300SD was not all that fun for my knuckles, so I m sure this time will be the same or possibly worse. Just ordered the fan clutch. Fingers crossed and knuckles bandaged.

What clutch did you buy? Assuming it's one of the "thin" aftermarket clutches, did you also buy the shorter bolt required?

Also, just so I am 100% certain that this is the right move - I am able to stop the fan from moving when the engine is running - by hand (I used a piece of rubber and not my fingers directly). This is an indication that the fan clutch is busted, right? This and the fact that in heavy traffic, it can get pretty toasty even in Canadian winter.

Nope. This is not a valid test. Read this post for more info. IMO it's very difficult (read: nearly impossible) to test a mechanical clutch in low ambient temperatures, because the clutch engages based on air temperature present at the clutch face - no matter what the coolant temperature is. As described in that thread, I only test on warm summer days.

When the clutch is not engaged - which is most of the time with coolant temps at or below 95°C - you'll always be able to stop the fan easily. This is normal.