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Radiator flushing

7K views 11 replies 8 participants last post by  e-420 
#1 ·
What more does MB do when flushing the radiator then doing it myself? I think my radiator might be plugged? I have replaced the thermostat and put in new MB radiator fluid, and it is still running hot. The aux fans do come on. It has only had it out of the garage on the road about three times over the last 2 1/2 years with the last being 11 months being in the garage. I have had so many problems with it; I just parked it. I am now trying to get it going again. After replacing the thermostat yesterday took it for a test run, it got up to 110c and held there. When I got it going up to around 80 it did go down to 95-100. I also have to state the aux relays were bad and could only locally find 30's versus the 40's so i put in the 30's until the 40's come in from ordering them yesterday. any thoughts and thanks for any input
 
#2 ·
You may indeed have a clogged radiator. You can try to flush it with a garden hose by disconnecting top and bottom radiator's hoses and run water through the radiator but I think you may have to replace the radiator. My SL was running hot too 2 years ago and like you it would go down a bit when driving on the highway. I knew it was not a head gasket issue so I started by replacing the thermostat, then the fan clutch, then flushed the radiator but the car was still running hot. I finally replaced the radiator and that fiexed the problem. Now the temp stays within the 80/90 mark even in very hot weather.
 
#3 ·
Thank you. That is what I what I thought I would need to do. I did call the local MB dealer this am and they shared they only drain and replace fluid and that is all they do for them flushing the radiator.

Has anyone used the flushing cleaning agent you can buy in the stores? Will using the cleaning agent do any harm to the block? Being a radiator is about $500, I wanted to at least try flushing it before breaking down and buying a new radiator. thoughts anyone?
 
#4 ·
I have always been concerned about possibly damaging the head gasket by running a radiator flushing stuff through the cooling system due to the agressivity of this thing, but this is just me. I may try that as a last resort on a old beater car but not on my SL.
 
#6 ·
Jay Leno uses a Waterless Coolant so there is absolutely NO CORROSION, whatsoever.... it's called "Evan's Waterless Coolant".
You never, ever have to replace this type of coolant, and your radiator, etc., should outlive the owner(s).

Here is the video with Jay Leno reviewing the coolant...




Take Care, and May God Bless, Arctic
 
#8 ·
Did you have a head gasket leak with oil? If the coolant was changed regularly I can't imaginable what would clog it. If you suspect oil in the system Mercedes offers this citric acid powder - you have to follow directions carefully but it will clean out what ails it.

You don't even mention what engine you have - if you have an M104 you could have rust accumulated from lack of maintenance (cast iron block) but other than that...

The radiators these days are throw away when done working - just replaced mine - plastic was cracking

I was surprised - my family's M272 E350 - 5 years old and the dealer has never flushed it. I asked him and he said it calls for coolant change at 15 years or 150,000 miles (!!!???)
 
#11 ·
15 years is on cars equipped with chem pack in cooling system to replenish chemicals that wear out.
That did not happen till about 2004.
MB dealers sell citric acid for radiator flush.
What I do with radiator showing lesser efficiency is buy 10 + gallons of distillate water,
1 drain the coolant via plug or bottom hose
2 refill with citric acid or other cleaner + DW
3 drive for 20+ miles, while operating heater
4 drain,
5 refill with DW
6 drive again for 20+
7 repeat 4-6 at least 2 more times.
8 drain well
9 put 1 gallon of MB coolant and top off with DW. For cold climate calculate if you need more coolant.
10 take 1 gallon of DW with me on the road and see when thermostat opens.
11 pull over, open the cap carefully and top off with DW when thermostat is open.
 
#12 ·
capacity is around 16 quarts, 4 gallons, with your proceedure you need to dump in TWO gallons of antifreeze. ONE is not near enough even in warm climates. you need the anticorrosion additives in the antifreeze so 50/50 is near what you need.

When you drain the M119, which I've done multiple times on two vehicles, you get about 9 quarts out. So.... the trick is to remove the bolt with a crush washer on the intake manifold near the thermostat, and add 2 gallons of antifreeze, and watch till it starts to come out of the bleed hole. then stop. One hot/cold cycle and you will need to add about another quart of whatever mix needed to make up the 50/50 mixture.
 
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