purplegrog

I have been getting notifications from the dash recently to top off my coolant level. poking around the engine bay, I was able to find a small crack at the neck of the radiator, as seems to be Mercedes' wont (3 of my 4 past Benz's have had this issue). I have two questions:

can the crack be repaired? e.g. can I epoxy the crack and trust it, or is the radiator only living on borrowed time at this point? When I replaced the radiator last time it was a bit of a PITA but doable. If I can just seal the crack and live with it I'm not above that.

Is the procedure the same for the 2003 W211? With the two cars having different engines I wasn't sure if any significant changes had also been made to the cooling system..

relinuca

Has the car ever been involved in a front end crash? The cracked radiator neck is pretty unusual...some kind of external stress caused it.

No harm in trying to epoxy it, but I'm not sure I would trust such a repair during Texas' summers.

relinuca.

arto_wa

Wow - could it be something you are doing?

I doubt epoxy or glue on the surface would be a long term repair if the original material broke.

kajtek1

Those plastic usually don't take glue. I would try with some testing on top of the plastic to see what will stick. Don't think Epoxy will, but I would start with Crazy Glue. If drop stays on the top and will not pop under screwdriver pressure - you should be able to use it.
Don't hold your breath.

rapidoxidation

What's your time worth? What is reliability worth? You can get a new radiator shipped to you for less than $250 from pelican...

kajtek1

Don't know if $250 radiator will provide better reliabitity.
Last time I bought Behr it was over $500 and that was like 6 years ago.
Add inflation....

rapidoxidation

Behr radiator for an '03 E320 on PelicanParts.com is $238.75 for the OEM one, $150.50 for the cheap one. The Mercedes branded one is $366.50.

kajtek1

Then parts research comes to mind.
I hear rumors that Behr moved the plants to China. Mine radiator was for diesel, what always is more expensive

purplegrog

Perhaps. I've had an 87 W124, 01 W210, 03 W211 and now an 08 W211. Of those, only the W210 never had an issue with the radiator and/or the water pump at some point.

After this repair my next plans are to replace the idler pulley, tensioner, and serpentine belt. On my 03 W211 after I replaced the belt and tensioner the water pump started going south. I'm planning on expecting to have to do the water pump on this one after that as a result.

Replacement radiator arrived today. Now the real test - finding time to do the job.

rocky raccoon

A cracked neck is non-repairable. Temperature cycling will recrack any adhesive. After the initial radiator failure and replacement on my old R107, I epoxyed a copper pipe nipple into the inlet side of the new radiator before installation. That cured the problem once and forever. I would do this as a preventive measure on any new Behr or next time you change coolant in your existing radiator.

If you must replace the radiator, look for a Nissens instead of the Behr. Nissens is a Danish company and their radiator necks are already reinforced. I have one in my W123.

purplegrog

Update for anyone interested:

I replaced the radiator Friday. Upon adding fluid back, the upper radiator hose started leaking profusely. I suspect the o-ring got compromised during the swap. so I had to get the upper radiator hose. I went ahead and ordered a new coolant reservoir too since the connection for the breather hose has been deteriorating for a while now, and I didn't want to be done in by that during a random outing. Parts had to be ordered and I had to wait a day, but I got the hose in, replaced it, and started filling the system again. Now the lower radiator hose is leaking like a sieve. I head back to the parts store and order the lower hose. $100 later, order is placed for the hose, but by now it is saturday afternoon and the supplier is closed. So I had to wait until Monday. Monday the hose comes in and I get that one swapped, system filled with coolant and (knock on wood) it appears life is back to normal.

Lesson learned - when replacing the radiator, buy replacement hoses to have on hand in case you need them. even if they weren't leaking before they may start after putting the new part in. Buy them from somewhere you can return them if you didn't need to install them and you'll save yourself three days of waiting on parts.

As a bonus - even though I ordered the parts through advance auto parts, since they apparently now own WorldPac, the radiator hoses I received were OEM Mercedes Hoses and significantly less expensive than they would have been had I purchased them at the dealer.

kajtek1

I am old enough to remember recommendations for hoses and belts replacement every 2 years, so even new technology improved - you've got 10 years and that ain't bad.
Now with new chem pack in replaced reservoir your chemistry is good for next 15 years.
Just don't break anything mechanically.