dj_lex

Hello guys.
The article presented below, with the 94 s320 is quite helpfull, and the modification link too. But my situation is a litle bit different.

While driving in stop-and-go conditions in very crowded traffic, with the a/c on, the water temp went to 120 degrees, without reaching the red zone. Even though the auxiliary fans were working, the temp didn't got low. however, stopping the a/c kept the temp at about 110.

I changed the thermostate, even though the old one didn't seem wrong, and also the viscous clutch. The old one looked pretty worn up. Still, the temp doesn't go lower than 100, without the a/c off, and driving in normal conditions. With the a/c on and in rough conditions, the temp reaches 115 and seems to stop there. I don't suppose it s normal.

The auxiliary fans don't start at all with the a/c off, and with the a/c on, the start at about 100*C and stop after 15 seconds and the go back on, and so on. I also don't think such short operation time is normal.

I have the old type resistor for auxiliary fans, the one (and only - not two resistors) shaped as a long cylinder. and i presume i only have the ECT sensor, even though there is something that looks like the a/c sensor, but with only one pin. If i remove the ECT plug, the auxiliary fans start after i start the engine.

What do you think? Bad radiator - i mean like clogged, because i have no fluid leak.

I would be interested in doing the resistor mod, but i don't know how.

Help will be appreciated. I want to keep the engine temp at 85-90*C as it used to be before the litle incident.
I'm DESPERATE !!!

NZ_Benz

Unless your in stop and go traffic the temp really should not rise above 90-95 even with the AC on. How old is the coolant in the system a flush might help.

Mazinger

Same here in my W124, everyone says its normal.

brett san diego

First thing I would do is get an independent measurement on the temperature to be sure that your gauge isn't giving you a false reading. The problem could be as simple as a faulty coolant temp sender. If the coolant temp is real, I would probably start with suspecting poor circulation in the system (blockage somewhere, radiator? or poor water pump performance? or significant air bubble causing pump cavitation?).

Brett

dj_lex

Thx guys,

I already checked the temp gauge, and the measurement seems to be quite accurate.

Still interested in that modification described in the other post... If anyone knows how to do it for my type of resistor, i would be glad if he shared it with me ...

RicardosBenz

I have the same problem. I dont' know what to do. The weather today in my area was approx 73 degrees, while driving with the AC on at medium power, my engine temp was holding at 110 degrees. What should I do?

pcmaher

You should always check that viscous clutch as DJ did...even though it looks like the fan is spinning, it might not be spinning fast enough. DJ, you may be interested in this link...

http://pages.prodigy.net/jforgione/MB_S500.html

pcmaher

You should always check that viscous clutch as DJ did...even though it looks like the fan is spinning, it might not be spinning fast enough. DJ, you may be interested in this link...

http://pages.prodigy.net/jforgione/MB_S500.html

dj_lex

Thx for the link. I sent an e-mail to this guy, maybe he can provide a mod for my resistor to work too.
However, changing the visous clutch, didn't solve the problem... I will flush the cooling system and clean the radiator...hope will kill the issue.

dj_lex

Hello again....

It seems that no matter ehat i do, the engine keeps overheating. So let's review what i have done about this matter.

First, i changed the thermostate .... no change.
Second, i changed the viscous clutch.....no change.
Third, i flushed the radiator, and used a 2+2 cleaning solution + new coolant...still no change.
Third, i welded the old viscous clutch, so it's always locked...water temp didn't go past 92 degrees. So, a small improuvment.

Now i put the new viscous clutch back, as the welded one, needed some adjustments, as the bearing had some material addition from the welding process, and now i have to make the surface plane...
With the new clutch...engine temp goes up to 98-99 degrees in light traffic. And this with outside temperatures of 15*C. I wonder where it will go at 31*C outside (

So any advice? I've heard rumours that i should change the radiator, but it's quite expensive, so i wouldn't want to change it and still have the same trouble.

Anyone can provide some advice? I intend to adjust the welded clutch and put it back, but i'm worries that at high enginr RPM (like 5000 RPM +) i could damage the water pump, and also there might be a possibility for the fan to crack at such high RPM.

What do you guys think? Changing the radiator might solve the issue? & Do you support the ideea of a welded clutch? THX

dj_lex

Please excuse my poor grammar. I wrote the topic in the dark... Sorry.

NZ_Benz

Are you loosing any coolant? Also there is a 'T' connection at the back of the engine block that can fail, if your loosing coolant that might be why the car is heating up so much, how olds the oil in the car?

dj_lex

I haven't detected any coolant leaks. The oil is quite old. Should that cause the engine to overheat? You say that the t connection in at the back of the engine block, this means is quite difficult to check it i presume. I suppose i must remove the shields to be able to access rhe beck of the engine, right?

THX

However i have a problem that i didn't take care of, but i don't know if this is the cause. The resistor that handles the auxiliary fans i broken, so they don't exactely start at the right time. But even when i put them in direct connection, the temp didn't go low. So i gues this isn't the cause for the overheating.

NZ_Benz

The reasin why I asked about oil is that the friction of the parts might increase, but that would be an extreem case, before you go searching for the T connector, I know it is at the back of the V12 and V8 cars but where on the I 6 I dunno.....

dj_lex

Thx, i'll take a look for the T connector this weekend. I just came from adjusting the welded clutch, and i'm going to install it back right now. This way until i find another solution i'll drive in a relaxed way

NZ_Benz

Thing is unless your loosing coolant, I don't know what you'll find, are you sure that the temp gague is accurate? Because doing all this stuff thats the only thing I can think of.

C280Sportster

My friend used to have an S500 (95) and it ran hot, one day in traffic - out of the blue - a hose broke and the car over-heated quick. Other than checking the fan, what about a coolent flush and new coolent. Maybe a relay is failing and the fans are kicking on late.

One measure we all should take is 55/45 (water/coolant) mix with a product called "wetter water" added to the coolent.

dj_lex

I think the reading is ok, because I used some tricky operation, with the rest button on the climate controller, and I see the water temp on the digital display of the climatronic. so I suppose that the respective sensor is accurte. the normal temp (analogue) gauge reads 2 to 4 degrees more than the electronic display. so I don,t think that the gauge is the trouble. now I just stopped driving and the car runs fine with the adjusted weled clutch. temp is stable at 90 with small 2 degrees variation according to the traffic. thx

NZ_Benz

That sounds like the 'T' connection

NZ_Benz

So it's all fixed good to hear.

brett san diego

I would not recommend this modification. I assume your modification results in the fan being locked up at all RPM's, or is that not the case? What exactly did you weld?

The viscous clutch releases at about 2200-2500 rpm so that the fan isn't locked up at high RPM. Presumably the fan is not built to withstand spinning that fast.

Jim Forgione's page describes a modification in which you trick the fan clutch into thinking that it is sensing high temperature at all times which causes the lock up at lower rpm at all times. The modification uses a screw to bend the bimetallic strip away from the lock-up pin. But, the high rpm disengagement still functions.

http://pages.prodigy.net/jforgione/MB_vfc.html

Is your modification similar to this one? or different? You really don't want the fan locked up when your engine reaches higher RPM's.

As far as your overheating goes... How is the condition of your water pump? Maybe it's time to try a new water pump and new radiator.

I re-read your original post. What is the "little incident" that you refer to?

Brett

dj_lex

No, my mod is not like that. I simply welded the ***** from the ballbearing of the viscous clutch, so you are right, the fan is always locked. I am aware that there is a risk for the fan being locked at high rpm's but it's my only available solution right now. I mean i have no guarantees that the radiator or the water pump is damaged, and they are quite expensive to make experiments.

However, i will try this mod you say about, with my new clutch, the one that is not welded.

The litle incident i reffered to was the sudden rais of the temperature. Before that My gauge never read temps higher than 90 * C even in heavy traffic and with the A/C on.

Thx.
Bogdan

NZ_Benz

There should be a hole on the bottom side of the water pump, after driving if you look in there you might be able to see a bit of coolant leaking not much but that would suggest a busted pump, also if you wiggle the pump with you hands and get alot of movement it's another sign, also remove the belt and try adn turn the pump is should be easy to turn if not thats a sign it's on the way out too. Better safe than sorry.

NZ_Benz

There should be a hole on the bottom side of the water pump, after driving if you look in there you might be able to see a bit of coolant leaking not much but that would suggest a busted pump, also if you wiggle the pump with you hands and get alot of movement it's another sign, also remove the belt and try adn turn the pump is should be easy to turn if not thats a sign it's on the way out too. Better safe than sorry.

dj_lex

Thanks. I'll check this too and let you know. Jforgione's mod for the clutch is extremely interesting I will aply it a.s.a.p. About the movement, even with the belt on, i can move the pulley from the water pump. Now, that i have welded the clutch, i can rotate the pulley along with the fan. It doesn't seem to be holding resistance. But i will check for the leak. See you soon.

Lex