I have a 1986 560sl (170K). It has been running at about 95-115 degrees unless I am going above 50mph. Two different shops have put the temperature gun on the radiator and showed me that it is hot in some places and cold in other places and diagnosing a clogged radiator. Since the radiator is only a few months old and was a new Behr, I took it back to the guy who installed it and told him what was going on. Problem, he refuses to admit that the radiator might be bad ("Behr doesn't make defective radiators, ever) or clogged. He is checking the thermostat (he put a new one in when he did the radiator), then said he was going to check the fan clutch (OK, can't hurt) but seems really resistant to check the radiator.

Does anyone have any experience with clogged behr radiators? I have heard that they cannot be rodded out because of the "turbulators" in the core. Can they be checked for flow rate without taking off the side tanks?

Any thoughts?

I have yet to see a defective behr out of the box. Seeing as the temp is order when you are moving I would look to the fan clutch. Did this guy flush the system/heater core before he installed the new rad?

Jonathan

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Blue Ridge Mercedes
Jonathan Hodgman
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Enthusiast Service, Restoration & Tuning.
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Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta

Thanks for your reply.

He did flush at installation. Is this clog something that could have developed after installation? I really only started noticing it in January (two months after new radiator installed). What about the very hot and very cold spots on the radiator, does that make any sense?

Also, the car used to run at rock solid 80, now, even at speed, it is more like 90-95, so it is not really normal in any situations.

I'm just surprised to see it happen is all.. Were this in my shop this would be the first Behr that failed so soon in it's life. The unit should still be under warantee so it's not like your guy will have to pay for another rad.. I realise double work is never much fun, but it's not that bad a job. You may consider offering to work w/ him a bit on the labour the 2nd time around..

You can check the fan clutch your self, it should give you a decent bit of resistance when moved by hand. If it spins rather easily it's getting tired.

Jonathan

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Blue Ridge Mercedes
Jonathan Hodgman
http://www.blueridgemb.com/
Enthusiast Service, Restoration & Tuning.
Follow Us on Facebook!
Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta

Could the clog have been from an incorrect installation? Could it be related to needing a valve job or something like that? I really appreciate your answers.