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  #16  
Old 07-12-2003, 03:28 PM
NikoE320
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Ok, here is my findings:
1) If I disconnect the 2 connectors in the white plastic sleeves and short the two together (the male part of the connector that has the exposed metal by touching them to themselves), I get no fan action.

2) If I disconnect the plug on the thermo housing (which btw does not have 2 wires, but four. one blue, one red, and 2 brown), then BOTH fans turn on at the same time. I don't think this is correct, right? And once I plug it back in and they stop, if you manually turn one of the fans, the other one moves a little bit as well. It did not do that before I did this test, as I was able to spin each fan independently and not have the other one move.

Let me know what I need to try next. thx!
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  #17  
Old 07-12-2003, 03:39 PM
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The fans are wired in parallel, so they both come on at the same time
There is never a time when just one fan works [ unless it is faulty]
So, you now know that the high fan circuit works
It is spec. to cut-in at 105/107
If it is higher , change the sensor you un-pluged
What u realey want to know, before changing anything, is if the gauge reading is accurate
[ simple resistance/temp chart verification w/ohm meter]

The low fan jumper should be done by pulling the plastic shield back and jump w/screwdriver blade without upplugging the wires.
You could be jumping the sw vs the circuit.
If still no fan , check the resistor behind drivers side headlamp.

[ also, when jumper sw, listen close for relay clicking.]
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  #18  
Old 07-12-2003, 03:55 PM
NikoE320
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Ok, I will go try shorting them out. But for the high fan, 107 is above the third tick. It's always above that, and also goes to where the picture shows it to be at, so you would think that it would turn on high at that point. Since I NEVER get any fan activity (low or hight), what temp should low come on at?
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  #19  
Old 07-12-2003, 04:04 PM
NikoE320
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Ok, I shorted out with screwdriver and the fans come on at low speed (relay clicks as well).

I do not know where the resistor is behind the headlamp.

Also with regards to checking the accuracy of the gauge reading, I have a fluke meter so i can do that part. Do I just measure resistance of the resistor, then do the math shown on some other posts with regards to what temp that should equate to? Then look at the dash and see if it jives?

Also for this test I started the car and let it run for 5 minutes and the hoses coming off the radiator were super duper hot already. This was in my garage which is cool. Still posibility that the incorrect coolant was used and it's running hot?
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  #20  
Old 07-12-2003, 04:04 PM
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What is a third TICK?
Your gauge picture tells me you are at 105C
[ approx]

Low fan has nothing to do with temp
It is activated by the sw at the drier that I want you to jumper.
It is a PRESSURE sw and is activated when the a/c high side pressure gets up to a high thermal load pressure spec.
Don't confuse the 2 .. they are INDEPENDENT of each other..

Rewmember
HIGH fan is to cool the engine off when it gets above 107C
The LOW fan is tripped when the a/c pressure gets high from , like - "A HOT day when you put on the a/c...
If you don;t put on the a/c , don't look for a LOW fan.. it won't happen.....
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  #21  
Old 07-12-2003, 04:14 PM
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I do not know where the resistor is behind the headlamp.
>

OK. So you now see you were jumping a DISCONNECTED sw before ..
So,now we know the integrity of the a/c low fan is OK ,
[ including the resistor]
EXCEPT, you do not see it come on with a/c on ..
Well. it won't til the high side gets up to pressure
That takes a HOT/HIGH ambient temp condition.[and you are is Seattle]
If you have a good , Hot day and it still does not come on, you may just be short [just a little ] of freon..this allows for a/c cooling, but not 100% ..IOW- not enough to trip the sw..[ or , bad sw] Gauges are require here for diagnosis...

I will post the other question in another post to save confusion
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  #22  
Old 07-12-2003, 04:21 PM
NikoE320
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The bar between the 80 and the 120, and I don't know if I agree with you that what you see in the pix is only ~ 105C. I have other friends cars that are the same as mine (one is a '95 E420), and even under the hottest days in traffic with the A/C on, they never get to where mine shows on a 60F outside temp in regular driving.

I'm with you though on your other comments, but remember about your Hot/High temp comment, I am in seattle so I should not be having these problems with the temp going so high.

I still need to know the location of the resistor. I'm heading out for a few hours and will read this when I get back. thx Arthur
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  #23  
Old 07-12-2003, 04:23 PM
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< >>

OK ... second part:

Kind of..
The best way is to take a look at the gauge when it has settled and then , without a time delay , take a sensor reading in OHMS

I leave the car running so I know we keep stable.
A better way , is to look at the temp/resistance chart and go to RS and get a high tolerance resistor and use that in place of the sensor..don't have to run car or heat it up that way.. you are just subing a known value from the chart

remember , the gauge is the single wire sensor , not the other
I will look up that spec , if u can't find it...
Also, to eliminate the =/- of the resistor, take a reading of its
value before usiong it for calibration purposes.. they are all out a bit
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  #24  
Old 07-12-2003, 04:32 PM
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< >>

Well, that TICK is 100c and the increments are 20C, so I read it as lower than 110, for sure ..
But . I agree that your temps are out of wack and , as I stated long ago , I don't think you have a fan problem,,, I think you have a slow/late opening thermostat
And , By my experiance , I'll bet it is a Whaler instead of a Behr..
Seen it many times on this model.
Change to a BEHR before you do anything is what I would have
done...along with burping the system to make sure they did not get an air pocket when doing the new thermo/coolant service...
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  #25  
Old 07-12-2003, 05:57 PM
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NikoE320

As a side-bar to all of this fan checking, which I am saving for future reference, I would also suggest running the car, get it warm (operating temp) and then check your radiator to see if it is evenly hot. You may want to remove the fan shroud to help in this.

Some months ago someone discovered that the overheating problem was a plugged radiator core. This is of course after fans, Tstats, viscous clutches etc.

Also, if you do remove the shroud, you can carefully use a hose and reverse flush the radiator to help remove accumulated bugs and debris. Just be careful not to bend the soft aluminum radiator fins.

Also, minor point to check, but do the front electric fans actually turn? I had an old 240D and it got too hot. Did the whole fan, jumping etc but discovered the actually fan didn't turn. Kind of locked in a way. Weird, until I discovered that some mouse had built a next between the fan and the condensor. Removed and cleaned it and it started whirring right away.

Keep us posted,

Haasman
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  #26  
Old 07-14-2003, 04:02 AM
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Mingson - fan clutch works like a charm from start of car to when it's running hot, i

Niko320,
I'm having the same problem on my '90 300e. At first I thought it was the front fans. They don't kick in until the car has reached 107c or above or if I'm running the A/C.

After reading hundreds of posts mostly form Larry Bible, Arthur Dalton, tkamiya and hassman. What I have learned and feel is our problem is the fan clutch.

An easy test that I learned form one of the members above is to let the car run until you reach operating temp. Watching the location of the fan, with the hood up, turn off the engine. If the fan continues to spin more than one rotation, you have a bad fan clutch. In my case, the fan spins about 20 times. The fan should only spin 1/4 or 1/2 of a turn at engine cut off. (normal operating temp)

I never suspected the fan because I saw it running all the time. But after reading more post after post I tested it and found it to be rotating 20 or more times at cut off.

After removing the fan, idleing for 10min AND DRIVING the car for about 2 or more miles with NO FAN and CLUTCH, the temp still reacted the same (110c).

Also, I thought that my Aux fans were not working because I could never here them. But they do work, try running your A/C parked, and watch the front fans, they should come on. They will also come on at a 107c or so.....

This is after I changed the cap, top fitting, tightened all coolant connections and changed the Tstat.

Water pump, air pump, Tstat and other stuff had been replaced by PO only 8 months ago. Even the fan clutch looks new. But still over heating.

After driving the car with no FAN and CLUTCH, I was able to feel the radiator and all was HOT!!!!. Ouch! So, I don't suspect the radiator to be the problem.

From your post, the only thing you have not clarified in detail to work is the fan clutch. Try the test and let us know!! You might even want to remove the fan and bring the car up to temp. Does it reach the same temp with or without the fan? Does the fan continue to spin after shut off? Remember, I drove mine without the fan and the temp acted the same. 110c + .

stevo
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  #27  
Old 07-15-2003, 12:11 AM
NikoE320
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Arthur, you said "the gauge is the single wire sensor , not the other". I still need to know based on the picture where exactly that is and what it looks like. You said it's behind the drivers headlight. Is it encased in some plastic enclosure? This is driving me up the wall trying to find it. Plz reference the picture that I attached for telling me where it is.

haasman, yes both fans turn just fine and also turn when I perform the High/Low fan tests where they both turn on beautifully. Is there any easy way to check for a clogged rad without having to take the stuff apart, which I would have to have my mechanic do.

madstevo, good idea, I will go try this right now and let you know with regards to the fan clutch and the aux fans with the A/C (which I know don't work but I'll try again).

thx
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  #28  
Old 07-15-2003, 12:49 AM
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<>

OK.. let'sa give it another go..

The RESISTOR behind the headlamp is the Dropping resistor for the LOW FAN.. it has nothing to do with the resistance of the gauge sensor.
The gauge sensor is the single wire sensor at the thermo housing. Next to the other one,[ meaning the one you unplugged to get the high fan on]...It has a RESISTANCE value ... if you measure that RESISTANCE [inside the sensor] and compare it to the temp/resistance chart, that will tell you if your gauge is reading correctly...forget the RESISTOR behind the headlamp.. that is a different RESISTOR [low fan]. which we know is OK b/c you have LOW fan. Forget that one for now and go find the gauge sensor and measure its resistance...
There are many, many resistors in your car...don't confuse one for another..
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  #29  
Old 07-15-2003, 02:03 AM
NikoE320
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Quote:
"turn off the engine. If the fan continues to spin more than one rotation, you have a bad fan clutch. In my case, the fan spins about 20 times. The fan should only spin 1/4 or 1/2 of a turn at engine cut off. (normal operating temp)"
So I guess the good news and bad news is that the fan clutch seems to spin indefinitely when I turn the car off. Does that mean that is the source of my problems? I haven't done the resistance measurement yet.

Quote:
"try running your A/C parked, and watch the front fans, they should come on. They will also come on at a 107c or so....."
Yes, with the car at operating temp and the A/C on, the fans DO come on. The tests I was doing before didn't involve the A/C as I couldn't get the regular fans to turn on without running the A/C to begin with, so I hadn't bothered with the A/C fan.

stevo, after my test I touched my radiator and it was blazing hot! When you fixed the fan/clutch issue, what was the end result with regards to your car's temperature? How much did it cost?
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  #30  
Old 07-15-2003, 04:40 PM
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Niko320

Looks like a bad fan clutch. I only fixed mine yesterday, drove around town with A/C on and temp stayed around 98c. Much better than 110c! With A/C off 85c - 95c.

You got two choices, rehab your current clutch or purchase a new one. (around $150) You might want to do both. Cost around $25 to rehab.

Heres what you need:
Silicon oil for fan clutch from a Toyota dealer, 3000 CST x2@$9ea.
RTV Silicon glue.
Needle nose plier
Syring (small, 10 to 15cc)
Blow dryer (your wife's will do fine) or hot air gun
Enough working surface to spin fan clutch.
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