PeachParts Mercedes-Benz Forum - View Single Post

G-Benz · #3 11-27-2001, 12:35 PM

I am guessing you have the same 3.2L M104 engine as I do in my 93 300E.

Ambient (outside) temperature will affect underhood temperatures to a degree (no pun intended). During the hot Texas summer months, I see temps over the 90 degree (celsius) range, and temps near 100C if in heavy stop-and-go traffic.

When ambient temperatures are below 80F or so, then 85-87C is what my temp gauge usually registers.

Water pump replacement is not fun, so I wouldn't be ready to point the blame there yet. I would however, check your thermostat and your coolant (expansion) tank cap...they are much cheaper to replace if you just want peace of mind. Temps go up if the coolant cap isn't holding pressure. Generally, coolant boils over under those circumstances.

Also, use a garden hose to remove any dirt and debris from your radiator...if the fins are obstructed with dirt, the cooling effectiveness is greatly reduced.

If you are still running you A/C in sunny California, check to see that the two auxiliary fans are operating. They come on when the A/C is on (low speed), and then high speed when engine temps get near 107C (I think). Since the A/C condenser sits in front of the radiator, it disperses heat to the radiator, which would raise temps. IF the aux fans aren't doing their job, temps go up fast!