Thoughts on Replacement Radiator? - PeachParts Mercedes-Benz Forum

dcotejr · #1 03-23-2011, 03:08 PM

My '81 300SD has been running hotter than normal (now about 95-100 versus 85 historically). On hills, reaching over 100... Thermostat and coolant replaced about a year ago. The radiator is over ten years old, so I plan on biting the bullet and replacing it. In reading thru some threads on the matter, it sounds like an aluminum replacement would be the best option. Anyone have strong opinions, one way or the other? Any brands preferred? Nissens, Behr, etc?

The last time I had it replaced (July of 1999), it was done as an emergency, somewhere off the beaten path in Georgia.... Don't want that to happen to me again...

Thanks in advance for input...

Stretch · #2 03-23-2011, 03:39 PM

No strong opinions here - sorry! But I'd look for a cheaper option first like muck stuck between the cooling fins / bent cooling fins... a slipping water pump pulley... correct coolant level...

MBeige · #3 03-23-2011, 03:52 PM

If the price between the two isn't significant, go with Behr.

The Nissens on mine has been doing good since 2005.

andrewjtx · #4 03-23-2011, 04:34 PM

I had a Nissens in the 84 and a MB Behr in the 85. No difference noticed. But the price on the Nissens is usually much cheaper.

dcotejr · #5 03-23-2011, 04:43 PM

In looking through a number of websites, the Behr seems to be at least $100 more expensive. Do both of these have the engine oil cooler integral to them?

MBeige · #6 03-23-2011, 04:53 PM

Engine oil cooler, no.

Transmission oil/fluid cooler, yes, since the turbodiesels never came with manual transmissions the radiators designed for these engines had the transmission cooler.

dcotejr · #7 03-23-2011, 05:00 PM

Ahh, I stand corrected. So both of these would have the transmission fluid cooler integral to the radiator?

Thanks so much for your input. I truly enjoy learning about my MB, and there seems to be many who are willing to share their knowledge...

Don

EDBSO · #8 03-23-2011, 05:12 PM

I would hit it with a Mercedes Citrus Flush first

Then fresh ZEREX G05 with

my frugal 2cts

JHZR2 · #9 03-23-2011, 05:22 PM

+1, citric acid flush, make sure your system is clean and clear. Make sure your ratios are correct.

kerry · #10 03-23-2011, 05:55 PM

Ebay has good prices on radiators.

vstech · #11 03-23-2011, 09:59 PM

first step would be to get an infrared thermometer and verify rad temps input and output... see what' temps you are getting... heck, measure the head temps too. you could just have a bad temp sender... then I'd pull the thermostat, and test to see if it opens at the correct temp, then I'd focus on the fan clutch... THEN worry about the radiator. they are well designed, and are RARELY the issue with overheating on these cars, if the coolant is maintained properly!
I'd pull yours, (it's not hard at all) and get some good condenser coil cleaner and soak it down really well. then rinse it off from the fan side out, and get it SUPER clean inside and out before tossing it to the curb.
it's amazing how much gunk gets past the a/c condenser into the radiator fins.

rhodes2010 · #12 03-24-2011, 01:07 AM

Listen to vstech and start by pulling the radiator and inspecting the outside of the radiator.

Does light pass through easily ??

I purchased and was ready to instal a new radiator and after cleaning the debris out from the fins it was not necessary.

A few weeks ago I pulled a brand new radiator from a junkyard benz and passed on buying it. Just could not justify it.

What I have learned is that with proper maintenance it just may not be needed.

My two almost thirty year old cars have the originals.
But I have cleaned the fins. Replaced a lot of water pumps, and a few thermostats.

The wierdest thing that clogs up mine is something that looks like hair.
Hair does not seem to break down. So some official radiator fin cleaner or
Drano will dissolve it.

I used a lot of air pressure and shop vac in blow and suck mode from both sides to really clean the fins.

Just my 2 cents.

Stretch · #13 03-24-2011, 04:38 AM

Whilst you are looking at the radiator have a look at the condition of the flexible transmission cooler lines - I read here on this forum somewhere that if these start to come apart the debris can knacker your transmission. These lines are a simple quite cheap - although a bit messy - fix. Well worth the extra $30 or whatever they cost (don't quote me on the price I'm totally guessing)

Mark DiSilvestro · #14 03-24-2011, 08:35 AM

When got my '84 Euro 300TD three years ago, , I replaced the radiator because it was running hot (95-100C) and there were traces it was starting a tiny leal. The new radiator didn't cure the hot condition, but since then I've checked with one of those infra-red thermometers and it's actualy about 5C lower than what the guage reads.
However, one issue I'd have with an otherwise good original radiator is the hose-necks can snap off the aged plastic tanks without warning. So I'm glad I replaced mine, since the AC still works on this car, and I do take it on occasional trips to Virginia Beach.
Personally, I prefer the old style brass-copper radiators as they aren't subject to 'broken neck' syndrome and they are repairable.

Happy Motoring, Mark

oldsinner111 · #15 03-24-2011, 08:41 AM

Personally, I prefer the old style brass-copper radiators as they aren't subject to 'broken neck' syndrome and they are repairable.

Boy you and me too.I'm thinking when my 83 goes,I will order a brass one for the 80 model SD.