can't keep my engine cool :(
 

I can't seem to keep the engine in my 500E cool, my fans keep turning on so late. My fans will not turn on until it's half way between the very top mark and the mark under it. It ended up overheating and smoking yesterday. It's 90 degrees outside and i'm driving around with the heat on full blast just to try and keep the engine cool to suck all the engine heat in to the cabin. If it's at night it will sit right on the mark before the highest temp gauge mark, which I assume is pretty cool because it's just one notch up from 80...so i'd guess it's around 95 degrees or so? But during the day in the heat it climbs all the way up past that mark, half way to the highest mark, and the fans still won't turn on!! It's sitting there and the fans are completely off. So i turned the heat on to suck some of the heat in to the cabin, then eventually just pulled over because it wasn't going down much. I'm ordering JimF's cool harness to turn the fans on sooner, until I get it does anyone know of a way to keep the engine cool or to toggle the fans on or anything that could help? It's kinda hard to not be able to drive your car more than 5 miles during the day :) Thanks guys!

...sounds like its time to do a complete cooling system check-up which will include but not be limited to (its imperative for a 500e cooling system to be at 100% effectiveness):

review for:
>fresh OEM MB coolant in the correct % to distilled H20 (check service records, needs to be done every 2 years), correct coolant level, no coolant leaks
>review thermostat
>review correct cut- in of low, med, and high speed Aux Fans (resistor/ fuses may need replacement)
>review correct function of clutch fan

also helps to review cleanliness of the air filter(s)- you have 2 of them....if they're dirty and clogged- - it won't help matters starving the motor for air

>in a healthy 500e, the low speed fan will be on w/ a/c on...
do a search to find the info on med and high fan temp cut in's

>>>JimF's cooling piggy tail is great "insurance" and appears to be an effective "add-on modification" when mated to a healthy and 100% effective 500e cooling system (not a great answer when mated to an ailing system)....<<<mated to an ineffective system, you'll probably just burn up your fans prematurely as they'll be on 100% of the time

good luck and let is know how it turns out!

-fad

Give some thought to a lower-temp thermostat.

The highspeed fan turns on at 107 i'd guess, that's where it seems like the pin is at when it turns on. But when it sits around 100, no fans are on at all. it's silent under the hood. Should a fan be on? 1 fan on? The car was smoking with the temp around 112 maybe? It seemed like water vaper more than smoke. I checked my oil and my oil was a little low, i don't know if that could have contributed. I am taking the car in to the shop thursday, so let me know what you guys think, i want to avoid having them do as much as possible. Let me know what i can check, when the fans should be on and everything, i'd greatly appreciate it.

Most MB's will run 100C or a little higher in warm humid weather with the AC engaging.

A temp of 112C is NOT overheating, unless your coolant/H2O is WAY off.

I agree with many of the above comments. The fan turn-on MIGHT be a problem, but you've got to approach this as a complete diagnostic of your cooling system. I would be especially concerned about the "smoke" that occured at such a low temp.

My fans seem to be running normal from checking them. Could the smoke have been caused by low oil? It was 1/4 full. It seemed like it was water vaper, it didn't have a horrible smell to it. I believe it was a white or a grey, it was definately not black. I have noticed that i my A/C is on, after i park the car, water will drip from underneath the chassis. I'm guessing from condensation? I'm pretty sure the car was not smoking until i went to park it, becase i was at a stop sign, at a complete stop and i saw no smoke at all. When i went to pull in, i was afraid i was gonna scrape my bumper, so i jerked it backwards in reverse and that's when it happened basically. Could some of that condensation hit a warm part underneath the car to cause it? What can i check to find out what was the cause of the smoke?

I had a similar problem. My car has two fans, an electric aux fan and a mechanical fan.

My car also has a temperature switch for the aux fan, a switch for the mechanical fan and a temperature sender for the instrument panel.

It sounds like the switches are not hooked up properly or there is a short, a benz stock cooling is very strong and should handle up to 115F outside temp I think.

I would replace: the aux fan switch, the mechanical fan switch and the temperature sender and the thermostat. I will be one of those solves the problem.

...sounds like you'd benefit with peace of mind most from having a qualified tech actually review these critical areas on your vehicle then afterwards review findings with you

if you do not have maintence records for your car- - now is the time to establish a good maintence and record program

>oil & filter changes
>coolant and hydraulic fluids
>alignment/ tire balances
>15k, 30k services
>etc.

though robust, the 500e requires maintence as all MBs do to provide the best motoring experience

...don't think its common for a 500e needing a couple of quarts of oil to 'smoke' or overheat...if you added a couple of quarts of oil when the stick was at 1/4--- keep in mind that there is still about 6 quarts in the sump (1.5 gals)- - so its not entirely dry>>> if you're using oil between changes (enough to require a couple of quarts), this may be a sign of worn valve guides and you may wish to address it

keep a close watch on the oil usage and on the temp gauge....a through inspection is in order from a qualified 500e tech

-fad

forgot to mention, with my car only the aux fan was becing activated at like 115F above, it would cause the temperature to swing up and down, since I have replace that stuff, the temperature is almost dead steady, even with the ac on at a stop light for a bit.

Alright, i'll have to get it checked out. I keep a good record of everything and the car has been extremely well maintained, oil changed and everything. I'm taking the car in for a window problem, i'll ask them to check it as it will be there for a couple days while i'm out of town. Thanks again.

Could it have been my brakes that were smoking? It wasn't heavy smoke, but it was a sufficient ammount. When i originally opened the hood, no smoke was coming from the hood, it was coming from the front sides of the car. After the hood had been opened for so long, then smoke started seeping up and through. When it originally hapenned my GF said "your brakes are smoking" and i had completely forgot she said that. Before we finally stopped at the putt putt place, i had driven about 4 miles with speeds ranging from 80-100 stopping quickly and accelerating, and back and forth. But could brakes create that much smoke? Like the smoke was billowing for maybe a minute straight before it stopped.

Btw...my brakes keep squeeling horribly when i'm stopping at low speeds, is there any way to get that to stop?

...for a definitive answer to your latest inquiry you may wish to request the tech to additionally access your braking system (if you're not qualified- a pro offers the best counsel)

>there may be aftermarket pads causing squeaking or they may be in need of anti-squeal MB lube on the shutter plate, or even be worn out

..if you're going to be enthusiastically driving a machine 80-100mph stopping quickly and accelerating>>>it best to be responsible and take your driving seriously.... by ensuring your machine is 100% at all times and invest in some performance driving instruction

(sorry to be such a preacher..., but I've seen too many young operators w/ inadequate driving skills & knowledge, inadequate decision making, and subpar unkept vehicles whom have lost the gamble when unwisely risking their own lives and the lives of their passengers playing with high powered machines on the street at triple digit speeds)

hope this helps
-fad

PS- I know...I know- - -it a challenge of self control to operate a 500e responsibly, safely (for driver, passengers & other operators on the road), & intelligently.

but could the brakes have smoked that much?

Short answer - yes. Plus, smoking brakes (and clutches) produce a very distinct smell which one never forgets.

...never have observed smoking brakes on a 500e (track and street) and never observed this happen on quite a few other MBs over the years

I've smelled burnt brake pad material and sweltering hot brake disks on vehicles just off of a track session...but not observed cars coming off with smoking brakes first hand (unless a line is ruptured and the fluid is reacting with something hot)

-fad