Warning Nissen Radiators Are Dangerous!
 

After finding a small leak in what I thought was my upper or lower radiator hose at a rest stop I turned around and made it home. Then I opened the hood, it seemed like the lower hose was leaking when all of a sudden the upper hose neck snapped spraying me with steaming hot coolant. At some point the radiator on my 1991 300E 4-Matic must have been replaced because I thought Behr was stock. I quickly ordered a Behr for $40.00 more than that POS Nissen. Is the Nissen company so cheap and negligent that they can't insert a simple metal sleeve in the neck like Behr? I would really like to get my hands on the neck of the engineer that thought reinforcement was not needed after all over the years alot of clamping down occurs at this point. I guess thats why on all my other 1980's Mercedes and also on my 1973 BMW Bavaria the Behr's are still working fine. Opinion:Always buy a Behr NEVER buy a Nissen. Also be very careful around those Nissens they can and will blow at any minute!

None of the original equipment Behr's had that reinforcement in the neck either until 1992! Have replace 100's of those Behr radiators for that EXACT problem as well.......HOW old was the radiator?

Every day PLASTIC radiators are replaced for that problem on almost ALL brands of cars!

I reinforced the neck by inserting a metal pipe to fit (hardest part is finding the pipe) attached w/ heat resistant silicone gasket in a tube (forget the exact one but it was way over the heat range). 8 years and holding!

I have had the car for 2.5 years and its a 1991. It seems like it should have lasted longer. The Behr on my '73 BMW is all metal. Its a shame they are not made that way anymore. But I guess thats true with many things. I read about a company on this forum that makes all stainless ones,but they were around $700.00(and probably worth every cent). Thanks for the replys.

Due to paranoia, this was one of the first things I did to my car; I bought the kit from mercedesource.com, which uses a copper pipe and plumber's epoxy (really, really strong, waterproof stuff available at Lowe's or Home Depot). A guy told me that they used to use this stuff by the gallon pail repairing oil pipelines!

i know "be cool" makes custom radiators. just send in specs. no idea what they charge but theyre all alluminium wich = long life.

I'm sure the engineer knew it was needed. It's the bean counters who's necks you want.

Had similar issue. Car overheated in stop and go traffic, cracked the upper neck. I replaced the radiator, and also replaced the coolant reservoir cap. My theory is if the pressure got so high to crack the radiator, maybe the safety valve didn't work right. Taking it one step further, why did it overheat? I'm thinking the aux fan wasn't working.
Anyone know how to test the fan? 88 300e

I usually test fans by removing them from the circuit and applying 12v directly to the terminals.

I can't seem to locate the plug to disconnect it. Not a dummy on cars, this thing just seems to be doing the Houdini on me

What he said!:D

If your radiator is in good shape otherwise...a fix post crack also works...I know but when I was in school every penny counted.

I read somewhere that if you unplug a certain connector, it senses a high resistance value, which is sensed as an overtemp, and should energize the fan. In essence, tests the whole circuit. If the fan fails to energize, then move on to testing the fan directly.
Anyone know of this method, which connector to unplug? 88 300e

I've yet to see a newer Behr with a reinforced neck. Somewhere along the way they quit doing that.

My Behr is no better than your Nissen as far as I'm concerned.

Maybe someone has a Behr source that still provides a reinforced neck.

My 1992 300e had new radiator in 1994/5......Origonal customer complained of 'drive through overheat'...puking coolant. This was one of the items replaced by MB, including a new cylinder head, although it never cured the problem...when I got it for service in 1995 I found one fan failed to come on.

This '94 BEHR radiator has metal inserts in both top and lower hose neck fittings.

FWIW......Most neck fitting breaks occure due to hardening of the coolant hose and sagging/broken engine mounts allowing the hose to overwork the neck. ( Apart from the usual overheating weakening the neck material. )


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