thermostat replacement

[Mark DiSilvestro]

Originally Posted by 240Dog

Admittedly Tom, I never spend any time sitting in traffic and thats probly where cars overheat the most. But for those who do, they oughta bypass the over-engineered and equally ridiculous automatic auxilliary heating fan switch that never turns on and install a dash mounted manual toggle switch instead.

Learned to hate abs brakes when driving limousines years ago. In the rain they really suck. If I were you I'd be scared for the wife and kids having abs brakes on a rainy day. BMW motorcyles actually put em on their bikes for awhile, can you believe it? Some of these engineers oughta be lined up against a wall and shot.

And when MB first invented ABS brakes they refused to file a pattent. "Sharing safety" with the rest of the world was the PR rap, but some of us believe they just didnt want to take the blame when motorists found out they'd rather have regular power disc brakes instead.

Meanwhile safety and emissions regs were written to protect the American automobile industry and gas companies you understand. They've got nothing to do with building safer automobiles or protecting the environment. Remember when fuel injection systems were restricted on imported cars? That was because nobody in Detroit knew how to build a competing product.

Well, for those ranting against nanny-government and electronic automotive technology, the latest wrinkle is electronic stability control. Some advocate making it mandatory in a few years. Perhaps fine on a new-car, but it's another layer of potential electronic trouble and repair frustration for the used-car buyer. Compared to that, the shroud and auxiliary fan on my 25 year-old 240D is a non-issue.

Happy Motoring, Mark

[300SDog]

Electronic Stability Control for top-heavy SUV's that roll greasy side up.... Did Congress come up with this idea? Why dont we tax auto companies on engine displacement instead, same as Europeans been doing for decades.

But i think the real question about fan shrouds is that after going through the hassle of pulling one - does anybody really want to put it back. And yeah, am thinking everybody with an auxiliary electric fan should have a manual bypass toggle switch. In fact I'm surprised MB dealerships dont stock an aftermarket manual overide kit along with apologies that the absurd automatic sensor switch for the aux fan will otherwise never do anything when you need it most.

[Mark DiSilvestro]

Originally Posted by 240Dog

Electronic Stability Control for top-heavy SUV's that roll greasy side up.... Did Congress come up with this idea? Why dont we tax auto companies on engine displacement instead, same as Europeans been doing for decades.

But i think the real question about fan shrouds is that after going through the hassle of pulling one - does anybody really want to put it back. And yeah, am thinking everybody with an auxiliary electric fan should have a manual bypass toggle switch. In fact I'm surprised MB dealerships dont stock an aftermarket manual overide kit along with apologies that the absurd automatic sensor switch for the aux fan will otherwise never do anything when you need it most.

Well, when a W114 250 was my daily driver 10 years ago, a working AC was important, so I certainly didn't want to discard the fan shroud. On a hot day with a hot engine, I noticed that the aux fan would come on automatically if I turned the ignition on after the car had been parked for several minutes. I assumed it was because the underhood temperature had exceeded the limit of the fan switch on the AC receiver-drier.
I thought it was kind-of neat.

Happy Motoring, Mark

[300SDog]

Sounds like you've cracked the mysterious fan code. So the trick is to shut down the car when it's running hot, return awhile later and turn the key on with the AC unit (itself rarely functional esp. on 123's) operating all the while. Seen this happen with girlfriend's Toyota the same way without having to turn the key. But never heard of anybody overheating an MB with the aux fan coming to the rescue. Maybe its the key trick that fools everybody or folks get faked out by instinctively shutting down the AC when the car overheats.

Meanwhile next Summer as a service to the community I might assemble kits of measured wire lengths and illuminated toggle switches to sell on ebay as MB elect aux fan overide systems. And should probly take the idea to the dealership. Local independent MB shop recommends replacing the crummy plastic w123 radiator with a superior mitsubishi unit too. Can vouch for this myself as an excellent improvement, got one on mine. And finally does your 240D have an oil separator that returns oil to the crankcase? If so, you can improve the system by drilling a small 1/16" hole in the top to relieve pressure and then none of the oil breather hose fittings will bleed oil.

I think the simplicity of 110's and 111's oughta set the standard for judging what's worth having on all MB's. Can recollect they had optional auxilliary electr fans, huge double electr fan set-ups for Africa version 111's early as 1965/66 or beyond. But no fan shrouds until they were mandated by congress circa '74.

[Mark DiSilvestro]

When I bought the 250 in '88, I had to repair the AC. I replaced the compressor seal, clutch-pulley bearing, high-pressure hose and installed a new reciever-drier with aux-fan switch. That switch operated the aux-fan when the reciever-drier temperature reached a certain point - I think about 130 degrees F - and a level easily reached underhood while parked, with a hot engine on a hot day. So the aux-fan would often come on when I turned on the ignition, even without the AC.

As far as the shrouds go, I think the US demand for air-conditioning had more to do with it than federal regulation. Last year I worked on a '66 W108 250S that had an OE air-conditioner and fan-shroud. Of course, the added heat from the thermal-reactors fitted to US-market cars around '74, probably made fan-shrouds mandatory, even without air-conditioning.

Happy Motoring, Mark