M119 Radiator Overheating
 

I have a 99 s420 with 45k miles. I thought my overheating problem was due to the cats but I replaced everything from the cats to the rear muffler and 02 sensors but still I am staying at around 100C (MOSTLY ON HIGHWAY). I have had my coolant changed at the dealer, so I think it is not my coolant/H20 ratio. The dealer performed a roar test twice and reported it stayed at 84C. Also I have had my oil pump switched out too. With my generous warranty dwindling to an end, I was wondering if my radiator is the culprit. Please post on what should I do?

Also on my 97 E320 rear door, there is some crackling noise once I it is moved and it doesnt slam good. Is the problem my door check straps.

Have you replaced your radiator and thermostat?

:-) neil
1993 500E (M119 engine)

not yet.

so should I go try to make the dealer replace the radiator. What is a roar test

Are you sure that anyhting is really wrong?
 

At highway speeds with 80F temp and 80% RH using A/C, staying around 95-100C is not bad!

Check the coolant ratio for yourself and make sure it's no more than 50/50, preferably 40/60 (af/water) ratio.

If you think something is still wrong, check the thermostat!

Wonder what a roar test is? ROAD???

I would second JimF's comments. My M119 engine runs 90-100 degrees with ambient temp >80, at highway speeds. This is despite having Water Wetter, a new water pump, radiator, and thermostat, so I am PRETTY SURE the system is functioning as efficiently as it can ...

The "roar" test is also known as the viscous fan test.

Based upon temperature and RPMs, the viscous fan is suppose to engage at x-degrees and y-RPM, and disengage at z-RPM.

Viscous-Fan coupling airflow temp: 92-100C
Safety Cut-off Fan Speed: 4500, engine RPM 3250

Also, it's called a "roar" test because if it's hot outside and in the engine-bay, once you hit about 3500 RPM the viscous fan should be engaged and you'll hear the "roar" of the fan.

:-) neil
1988 360TE AMG
1993 500E