1994 C280 running too hot
 

Dunno what's up. I changed the oil ((have not changed the oil filter yet, though)) using Mobil 1 tri-synthetic 10w30.

It will run above normal without the A/C, and when the A/C is turned on, zoom! up the temp goes.

I used a topsider to remove the oil. It only pulled about 7 quarts out and when I refilled it, it was just to the max mark on the dipstick, so I sucked some out...now it's about 3/4 of the way up between the min and max.

And, to top it all off, the Check Engine light has come on :confused:

How hot is it getting? Start by checking the aux fan fuse.

I have been hitting 100 degrees with the A/C on on hot days in stop and go traffic lately. As soon as I get out in the open it stays right at 80, or a little higher. Is this what you guys are experiencing, or is this hot? And it's a 94 C280 too.

That's close to what we're getting, but I would say we're between 80 and 100 during highway use and at or a little higher than 100 during stop and go in town type driving. This is up quite a bit. This car has yet to see 100 until the past couple of days.

We're in Northwest Arkansas and temps. have been mid 80's in our area.

In hot weather, stuck in traffic, with cold air blasting from the vents, both our 98MY cars will run a constant 94-97C, with 100C occasionally.

Once traffic opens up, 85-89C is about the temp it falls to.

Open road in cool weather sees a constant 83C.

(BTW, I checked these temps with the PBU diagnositics mode, so that's why they are more accurate than the guess-the-gauge numbers)

What is PBU diagnostics mode?

On my ACC panel, if I press the "rest" button for five seconds while driving, it cals up the diagnositics panel, giving the readout from many of the car's sensors.

I can check coolant temp, interior temp reading, bumper-mounted outside tep sensor, heater core temp, AC pressure, refrigerant temp, rpm, road speed, and charging voltage to name a few.

I can't remember how to call it up on your pre 1996 ACC unit, but it can be done. Check David C Klass' posts on this subject...

as well as this link:

http://www.peachparts.com/shopforum/showthread.php?threadid=9166

Wow, handy information. Too bad it's for 1995 and newer :(

I might try it on the 1994 just to see what happens.