W126 Radiator Blown! Temp hits 105 Deg.

[Mervyn]

Bad day for me. On a 20min. easy drive to the beach, I saw the temp gauge shot up to 100-105 deg. I knew something was wrong. I opened the bonnet and gosh, blue coolant was splattered all across the engine bay , and smoke was emitting from the radiator with a typical hissing sound.

I opened the radiator cap an hour later, only to find that it was as dry as a bone inside. Took me 3 litres of water plus some MB antifreeze to bring it up to level again. While I was pouring, the radiator was leaking. Had the car towed to the workshop, but because it was a Sunday, I could only know the outcome tomorrow.

My question to fellow forum members is:

1.Apart from replacing the radiator, are there any other parts that could be damaged by the overheating? A friend suggested the engine gasket and seals might be damaged, or even worst, an overhaul might be needed. Is that true?

2. Are there any parts that I should replace together with the radiator, since I'm getting the mechanic to do it anyway?

3. Any other tips or advice that I should know?

Would appreciate any input, thanks!!


Mervyn
1983 W126 (280SEL)

[420SEL]

I would suspect that there should not be too much damage other than to the cooling system since you ran at high temperature for such a short time. If you had been running at 105 degrees for an extended interval then there might be cause for concern. Best way to know for sure though is to ask your mechanic tomorrow when the cooling system is fixed.

[MB STARS]

Replace your radiator with new thermostat,radiator cap,inspect all coolant hoses,fitting,test fan clutch.

[Mervyn]

Jason and MBStars,

Thank you very much for the pre-consultation with my mechanic.

Just got back my car today from the workshop, and the following were carried out:

1.Radiator assembly replaced with new BEHR radiator.
2.Thermostat replaced.
3.Water pump assembly replaced.
4.Had the hoses, fittings and fan clutch tested. No faults detected.
5.Engine gasket was deemed to be OK. I hope.....

Total costs (both parts and labour) came to approx. US$330. Quite a bit on the high side, but at least it's done. I wished I could D-I-Y, just like many of the fellow members here.

Lastly, I have 2 questions:

1.What is the normal operating temp.? My mechanic says it should be about 90-95 deg. celsius.

2.Does Water Wetter harm the radiator? I'm intending to get one.

3.Is it possible to further cool the engine by adding an aux. fan? Mine is the M110 engine in a W126 chassis. Any advice on this?

Once again, I appreciated all your help, cheers!

Mervyn
1983 W126 (280SEL)

[JohninFla]

I think if your car has a/c, you have an aux fan already. See about changing the sensor that turns the fan on, to a lower temperature activation?

You got all that done for $330 USD and you think that is a lot of money??? I think a new radiator costs more than that for the part!!! And you got a water pump and thermostat?

I think you did pretty good!

Put your mechanic in a box, and ship him here!

[Mervyn]

Hi Johnin, I like your humour! Hahaha.....

Well, the exact breakdown is as follow:

1.BEHR Radiator Assy. (Made in South Africa) - USD$150
2.Thermostat - USD$12
3.Water Pump Assy. - USD$45
4.Labour charge for the above items - USD$123

All parts are new, not reconditioned. So I got a good deal? Geee......thanks for enlightening me!

Cheers!
Mervyn
1983 W126 (280SEL)

[mreid]

Sounds cheap to me and I use the Canadian Paso. As for wrecking your engine, as long as the heads still had coolant in them they will be ok. 105C is warm but not dangerous as long as there is coolant in the heads.

[Mervyn]

Mark, you just reminded me of something.

How do I drain off the coolant in the heads? I want to make sure the old coolant stuff (plus oil, rust etc.) is entirely cleared from my new cooling system before I pour in new water and MB antifreeze. Will the usual method of draining the coolant (that is, by unscrewing the plug below the radiator housing) do?

Also, can anyone tell me what is the volume of liquid in a W126 cooling system? I know about the 50/50 mix, but I do not know how MUCH (litres or gallons) to mix.

Any advice?

Thanks.....

Mervyn
1983 W126 (280SEL)

[Mervyn]

Mark, you just reminded me of something.

How do I drain off the coolant in the heads? I want to make sure the old coolant stuff (plus oil, rust etc.) is entirely cleared from my new cooling system before I pour in new water and MB antifreeze. Will the usual method of draining the coolant (that is, by unscrewing the plug below the radiator housing) do?

Also, can anyone tell me what is the volume of liquid in a W126 cooling system? I know about the 50/50 mix, but I do not know how MUCH (litres or gallons) to mix.

Any advice?

Thanks.....

Mervyn
1983 W126 (280SEL)

[mreid]

Mervyn

Your enginge should have a block drain on it somewhere in the midblock section of the engine. If it is a V type there will be one on each side. As for amount of coolant.?? I could not find a 280SEL in my service manual. It should be around 10-12 liter.