Plugged up Radiators

[Rocket]

It's been my observation, that as the miles go by,the plastic and aluminum radiators that we see on everything today, tend to get internally restricted. Has anyone out there found a good method to clean these and extend their useful life? Eventually they all leak or break, but if they are in good physical condition, cleaning them internally would be a good conservation of cash.

The factory service manual for the 617.95 Turbo Diesel Engine gives detailed instructions on cleaning/flushing the cooling system using a degreasing solution followed by clear water rinse and then citric acid flush. Although this is from a diesel manual, I see no reason why it wouldn't do just as well with any car. If you don't have the complete procedure, I will be glad to send them to you.
Bill Lewallen Lexington,Ky.

[longston]

I am researching this subject in some detail, as I need to repair/replace my radiator very soon due to a break in the plastic upper tank.

I personlly feel that the use of the proper antifreeze is the main thing needed to keep these radiators flowing properly for many years to come. You need to prevent, rather than try to undo the damage, becuase it's really much worse than just the restriction that IS caused by the use of the wrong antifreeze and/or poor maintenance. For detailed analysis of this topic, let me save you some time, and suggest this link to topic thread # 13292:

special coolant for MB?

What I have found is that once one of these radiators develop a problem, especially with the plastic tank(s), it is almost impossible to get it fixed right, and it ends up being less expensive to just replace it.

Depending upon your level of sensitivity to "genuine" Mercedes parts versus aftermarket, that means either a genuine Behr radiator, a Behr aftermarket radiator made by them, but without their name on it, or a high quality aftermarket exact copy of the original from Nissens in Denmark. There are many other aftermarket radiators available, but I don't have confidence in a product when the company selling me the item asks questions like: "is that with an automatic or manual transmission?; does your car have a turbo?"; and the ever popular, "that's for a diesel, isn't it?".

[Benzmac]

With the Behr radiator, the only thing they do is put a dab of epoxy right on top of the star on the upper tank and color the star with a marker on the sticker. It costs less and is the EXACT same part as Mercedes. It is the OE supplier.

The nissens is not an exact copy, but rather an aftermarket radiator. I have used them and I do like them. They are less costly than the Behr and tend to last longer without tank failure. Some times they are a little challenging to install perfectly, but I have had good results. I sell about 95% OE Behr and 5% nissens. The reason is customer perseption. But, that is OK>

Good luck.

[longston]

Donie,

Thanks for the correction. I haven't ever seen a Nissens, but I was advised by three separate sources that they were exact copies of the original Behr.

The Original Behr for my car would cost me $326, and the unbranded Behr would cost $175 + tax. Do you happen to know if the unbranded Behr comes from Wolverine? My source says that is the name on the box it comes in. Aside from that, is there any way to confirm that it is "a Behr in sheeps clothing"?

BTW, the last owner of my car just told me that the replacement in it right now was made in India...

Scott L.
The reason a shop selling radiators would ask if it was for a car with automatic or manual transmission, is because the radiator for automatic will have cooling lines in the bottom for transmission fluid cooling. Radiators for manual transmissions will not have the cooling lines. They can be interchanged but you will have to plug a few holes. Not reccomended.

Bill Lewallen Lexington,Ky.

[longston]

Bill,

I know that you're just trying to be helpful, and thank you for that, but my comments were meant to be facetious.

I KNOW why someone would USUALLY pose that question. My point was that anyone asking me that question after I just told them that the radiator was for an '82 Mercedes 300SD doesn't know Mercedes from BEANSEDES, and they might even be trying to sell me a "one size" radiator.

And just in case anyone wants to bring up the, "they're just following the prompts on their computer screen" argument, I would only see that as yet another example of why I don't want to buy a product from them. I personally don't like dealing with "parts" companies that sell products that they don't know anything about for cars they don't know anything about.

The key is to deal with someone that knows the car well enough NOT to ask irrelevant questions that only serve to erode the customer's confidence in their knowledge of their company's products.

I will now go see if I can find a 1982 Mercedes 300 SD with a naturally aspirated motor and manual transmission...

[Edited by longston on 02-04-2001 at 11:52 PM]

[Kebowers]

The aluminum core radiators WILL plug up if MBZ antifreeze is not used, and used with distilled water. Many /most 'green stuff' antifreeze formulations have 'silicone/silicate' corrosion inhibitors, and this stuff reacts with hardness in the water to make solid deposits that plug the passages. The only way to clean it out is to have a competent radiator shot take it apart and rod it out. New tanks can easily be installed. A rod out +top tank will cost (here in Houston ) about $125, not a whole lot less than a new 'after marker identical to OEM unit'

Best preventive is use distilled water and MBZ antifreeze.

[longston]

Kebowers,

while I agree with almost everything you said, there is one point I must dssagree with. The silicate, not silicone, or siliputty, is not the corrosion inhibitor component in the antifreeze. The silicate helps to lubricate your water pump and it's seals. The corrosion inhibitor in every green coloured Ethylene Glycol based antifreeze is phosphate. The others are borates, nitrites, and amines. Except for all of the new red, orange, and amber ones which have corrosion inhibitors that are "organic acid based". Mercedes in fact, uses a formulation of corrosion inhibitors that is trademarked and patented by BASF under the name "Glysantin".

For the full scoop check out this archived thread:

Coolant RED vs. GREEN