Please Please Help
 

I have already spent 600 dollars at a reputable shop TRYING to get this fixed!

I have a 92 300e its very clean and has been well taken care of. I just recently bought it from my aunt for my little brother. So its worth Keeping.

Now heres the problem...1 month ago the car started to over heat and radiator fluid came pouring out. I turned on the heater and drove the car to German Auto Center a few miles away w/o over heating it. They replaced the radiator tank and installed a new fan clutch, the old one was not engaging.

Here's the problem. If I drive the car easy OR hard and then stop By applying the brakes and waiting the temperature will rise and rise. After for 4 or more minutes, leaving the car in D and applying the brakes as stated before it will over heat way WAY past 100 C (to like 110 but I am sure it would still climb) but If I drive the car, the temp. will dramatically fall to 85-90. If I put it in neutral it still will heat up way way past 100 but at a slower rate. If I turn on the AC it will over heat too, but if I am driving it, like on the highway it will not over heat. My question is whats the problem??????


Also when the car is way way too hot it will start off the line very slow in 1st gear until it reaches 2nd and at that point it will drive normally

Cars are not supposed to over heat at a stand still and there not supposed to over heat when the AC is on. Could any one tell me what they THINK the problem is??? I would be greatly appreciated!Here's the problem

Yes. I think the auxillary cooling fans in front of the radiator are not working.
Gilly

Or an airlock bubble in the radiator system?

Whichever way, I think you'd find loads of technical support where you are.

Are the AUX fans supposed to come on when the car is over heated? Some one told me they are only supposed to come on when you turn on the AC.... In some cars the Aux fans turn on when the car is turned off, in order to cool the car down after you have finished driving.

Jay:
These are 2 speed fans. They either both run or are both off, I want to make that clear to you. If you see only 1 fan run, it means the other one is bad, OK?
Alright, these are 2 speed, or have 2 stages. 1st stage (low) is controlled by the A/C system. If the freon pressure is high enough, the low speed fan will come on, there is a relay and a resistor which make the fan run in low speed.
2nd stage (high speed) is controlled by engine temp, I believe on your car it should be switched on at about 105 Celcius. The has a relay also, but no resistor, gets 100% battery voltage to run the fans.
If it seems like the fans never come on, my gut reaction would be both fans are bad. That is, if neither the A/C nor the engine temp will activate the fans.
A simple test is to disconnect the engine temp sensor for the fans, the open circuit (high resistance) simulates an extremely hot engine and closes the high speed fan relay, so the fans should come on "full bore", high speed fan. I'm sorry but I can't remember the exact location of the proper sensor to disconnect, there are a couple different sensors. I know it is on the drivers side of the cylinder head, along side the valve cover. Maybe by trial and error you can locate the proper one. This should work as a test with key on, engine off.
If you have never noticed the fans run with an extremely hot engine, I'd say we are on the right track.
Alternatively, it could be the radiator is plugged internally, which I usually recommend a new radiator, OR the outside of the radiator, the fins, could be bent over in large areas and/or plugged with dirt, bugs, leaves, other plant life, all the other things that make this such a great planet. Between the condensor and radiator is the place to look for this problem, the area can be cleaned out with a garden hose, no high pressure washers as the fins are delicate and can be easily damaged by high pressure.
Gilly

Thank you very much for the help, I will be dropping the car off to the shop today. As for the Roulette, the car is never driven for more than 8 miles a day, to school and back. But it seems that the Aux fans only come on when the AC is running, and no I have not been running the ac I just tested to see what would happen. Thank you for the help.

Last thing,
Anyone know how to replace the light for the shifter selection? Mine has recently burnt out.

By the way, it was the AUX fans, even when i turn on the AC (as a test) they both do not come on....are these something I could replace myself? Cost? I am taking the car to the shop to be serviced anyway.

Thanks you for your help,

-Jay

Jay:
It may or not be normal for the fans to come on with the A/C. As I described, the fans will come on low speed IF the freon pressure is high enough. This of course is with the A/C switched on. Usually the fans will cycle on and off, as the fans help reduce the high pressure just as they reduce the coolant temp. If the A/C system works well, I would ignore them coming on with the A/C on, at least this establishes that the fans do in fact operate. The second stage, high speed fan will come on only when the engine temp reaches either 100 or 105 degrees celcius. If the low speed fan is already running due to the A/C , the high speed fan will take over.
I would try getting it up to an overheated state, over 100+ to see if the fans come on high speed. Well, first I'd try finding the temp sensor as I suggested just to see if they come on high speed if you pull the connector, just to test the system itself, then run it up to a high temp to see if the fan comes on high speed. If the system is capable of working by pulling the connector, but doesn't come on at high engine temp, then I'd try the temp sensor itself.
If the fans are working OK, coming on at high engine temp, but the overheating concern is still there, then I'd look at the radiator concern I mentioned before.
One final observation is that you said the engine fan clutch(on the front of the engine itself) was replaced, just be sure they didn't put the blade on the clutch backwards, it'll be easy to tell if the fan is blowing back towards the engine with the engine running, or if some dufus has it backwards and it's blowing forward towards the radiator. Seen this happen at a body shop once.
Gilly

On the shifter light, try:

http://www.peachparts.com/shopforum/tech-help/25514-shift-lever-backlighting-1994-e320.html?highlight=shift%2A+light

On the overheating, do check out the fans as a likely culprit, but out of curiousity, when was the last time the cooling system was flushed and re-filled, and the thermostat checked? 300Es don't like to go without fluid changes every couple of years, as it can impact lots of things, including the water pump. Good luck!

Jay before you buy a fan make sure it not really working,test it by jumping it directly to the battery if its working probably its the relay.

gillybenztech is da man!

Just out o' curiosity I pulled off the wire from the BLUE temp. sensor on the front of my 119 engine and the high-speed fans came on. What a great, quick test of the system!

I'm a bit suspicious of the engine fan clutch (just replaced?) based on the vehicle speeds that the problem occurs. Auxilliary fan problems typically show up when engine is at load thermally (airco., high ambient temp., prolonged stop and go, etc.). Temperature rise, at this time of year, when just stopped from speed would indicate air flow problem; ie. #1.engine fan/clutch #2. aux. fan(Gilly has given you the techniques to check that) #3 clogged fins. Just out of curiousity have them check their engine fan clutch installation. Maybe, maybe not.

John is right on with his advice. The coolant should be replaced every 3 years, but more importantly I should have mentioned the thermostat. Wouldn't hurt to replace it.
I've never replaced very many fan clutches, seem more likely to get broken in an accident than to just "fail". But the fan is seperate of the clutch and can be installed backwards, that is, blowing air from the engine to the radiator rather than sucking air through the radiator from the grille. Just run the engine and put your hand by the front of the air cleaner, should be easy to tell if it's working correctly.
You can pull the couple of clips that hold the radiator in place and carefully tilt the radiator towards the engine, and using a flashlight you can look between the radiator and A/C condensor to check for external blockage.
400E: This checks everything for the engine control of the fans EXCEPT the sensor itself. The sensor can be checked using a chart and a ohmeter.
The A/C low speed fan can be checked by shorting together the high pressure switch, except for models using a dual fuction pressure switch, I can't swear that it will work on those models. The sensor for the A/C is checked by monitoring pressures of the A/C system while monitoring the closing of the switch with an ohmeter.
Gilly

Replace your "radiator" cap -- it's on the coolant tank.

The one on my 300TE was bad - previous owner told me it "overheated with the AC on", was "fixed", but couldn't remember how. AC was discharged, so I switched it to 134a.

My sister's Volvo blew up on the way here from Florida, and I couldn't get it fixed in time for her to continue up to Cleveland, so I lent her the MB. Sure enough, when she pulled off the highway, the low coolant light came on.

I fixed her car and drove to Cleveland, then drove the MB back home. It was fine until I got to Cinncinatti, where I stopped at a rest stop. Blew coolant all over the parking lot.

Spent a couple hours driving around and stopping at every parts store I could find, and finally found a place that had a radiator cap, and sure enough, with a hot engine (off the road for about three minutes), there was no pressure in the coolant tank.

Popped the new cap on, and problem was gone. Temp goes up to about 100C in traffic, comes down pretty quick when back up to speed, just like it should. I have a new visco clutch I've not gotten installed as I think the old one is bad, but haven't had a single problem with spilled coolant since.

Pretty cheap fix -- $5.00 for the aftermarket, $13 or so for the MB cap I bought after I got home.

If the cooling system doesn't pressurize, you will lose efficiency and the coolant will boil in the head when you slow down after a highway run.

Peter

:D :D Take all this advise and you'd have rebuilt your front end of the engine compartment - short of replacing the radiator tank. :D :D

Hope the problem would have been sorted by now.

Good day all.
:)