Interesting note from article - NA antifreeze is has higher Ph value than MB antifreeze which attacks the plastic top of MB rads. Article states that the plastic becomes crumbly which causes neck of rad to break off. Could this be the reason for the threads on this site about broken rad necks??? Has anyone been using MB antifreeze and still have their rad neck break??

The newer radiators have a metal insert in the neck to prevent them from breaking off, however, I am unsure of the year that the changes were made.

Does anyone know what year they started putting the metal insert in the neck of the radiator?

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

I'm not buying that bit about Ph crumbling plastic. In pool chemicals both Ph increaser and decreaser come in plastic bottles and I've never seen one crumble. Plastic is impervious to ph. What it isn't impervious to is heat. And hoses suffer from extreme heat also. I think what scares me most about the elevated temps is that we have this old mindset that we need a "safety" range. In the old days of 180F engines, we didn't sweat until they reached 210F. That was a long way on the old mechanical temp guages. Now, "green" engines are already set at 195F so there goes half of our "safety" range. After all is said and done, the engine that operates closest to it's thermostat setting will live the longest.

AH - But Cap'n - the containers for the Ph stuff for your pool is not subjected to ongoing temps of 90-110C plus 20 lbs pressure. I don't know if MBUSA is right (but I think they should know). That is why I asked if any one out there was using MB antifreeze consistently and still had the rad break. If most people reply that they used NA antifreeze and had broken necks - there may something to what they say. Any takers for comments on using MB antifreeze exclusively??

I think the radiator neck problem is stress related, If Ph were the culprit, then the entire top cap of the radiator would fail, not just the neck.

Not sure if this is related or not, but I just had to replace a plastic thermostat cap on my 190-16v. It had started to leak from the plastic 'nipple' that is the begining of a hose back to the resovoir, and the piece broke off completely when i tried to examine it. This is not a 'stressed' part in any way except incorrect anti-freeze and high temps. Just for the records, my h20 runs about 85-90, but my oil goes to 100-110. Go figure.

Dan

Well, all plastic rads are subject to wear, and will break at some point.

It's common on Japanese cars. We use MB coolant in ALL our cars. We recently replaced the rad on our old 1988 Mazda 626. The dealership couldn't believe how long the rad lasted. Many of the mechanics have started using MB coolant in their own cars after seeing our 626.

I don't care why it works. It does, and costs little extra per mile, so I use it.

As to temperature, MB is one of only a few makes that has a REAL temp gauge, so ignore what you know with other cars.

My 1998 C230 reads a constant 83C at highway cruise with the AC compressor only pushing 2.5 bar at an ambient temp of 10C.

At an ambient temp of 32C, with the AC compressor reading 16.0+bar, my coolant temp reads about 97-101C, falling if highway speeds are reached consistently. Not much below 87C though.

Our 1998 E300 reads pretty much the same. Most late model MB's exhibit similar temp behaviour.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

Think about this for a moment. The role of the thermostat is to force the engine to operate at a minimum temperature, i.e. the degree setting on the thermostat. It opens when that temp is reached. Now, whether it's beginning to open or all the way open is irrelative, because everything that happens from this point on, lock up of fan dampers, startup of aux fans etc. is for the purpose of lowering the coolant temp down to where the thermostat closes. Then the process repeats. If you're thermo is open all the time, then your cooling system is inadequate either by design or malfunction. A good cooling system, be it on a Mercedes or an earthmover should keep the engine near the thermostat setting whether it is at idle or under load. If a manufacturer wanted the engine at 100C, they would put a 100c thermo in it.

would it be advisable to cover ones rad grill in winter to induce higher engine temps? mine wallows between 40-80 on the highway...

Sounds like you just need a new thermostat.

To Mercedes Fred
What kind of outdoor temps are we talking when you get 40-80 on your gauge on the highway???

the outside temp varies from -10C to -20C. Once im in town in stop and go traffic the temp guage goes past 80

WoW!! You don't need a thermostat, you need to move south! I have no experience with that kind of cold. Our freezers don't even get that cold down here. I'm out of this one.

here on the cold Canadian prairies - we have winter fronts with flaps. It is going to be below -15C close flaps - Daytime temp over -15C - open flaps - and always keep an eye on your temp guage.
Sounds a little strange that your guage will go below 80C at only -10C on the highway. Have your thermostat checked before resorting to a winter front. If your engine is not at aperating temp - excessive wear, poor gas mileage and other problems will exist. If you read higher up this thread you will see that the thermostat BEGINS to open at 80 to 87C.-engine is not holding temp - check your thermostat

Very interesting discussion. My 600SL runs at approximately 95-96 at steady cruise. But, the least amount of acceleration or a hill sends it 98C and the Viscous fan comes on 96-97. This fan is extremely loud and for top down driving it destroys the ambience. Any way to quiet it down but retain its efficent operation?. I wonder if the noise is the fan proper or the clutch.