I have seen it before but I'm a little hesitant to use it on an older engine, especially on a #14 head.

Some might need a little grinding on the fins to get the holes to line up.

Right on, Dave. Thanks. Rad has 287k on it, wp has 40k on it.

No, the elec fan would cycle a few times on its lower speed setting but the only time I have ever heard the high speed was when i jumped the 3 pin connector. I may be misunderstanding but I thought the elec fan speeds were controlled as follows (and correct me if Im wrong pleees!)

Speed 1 - controlled by a/c pressure, independent of coolant temp

Speed 2 - comes on at a wopping 128C, and shuts off AC compressor

Am I mistaken?

Ditto on your hose comment, Worldpac will get an earful. My local Benz dealer is awesome and gives me wholesale pricing, they just didnt have the hose in stock when I called so I went with WP. Big freakin mistake!

OK on todays ride home it didnt pass 100C, and every time it hit 100C it quickly cooled back down to 90-95C. Wasnt for lack of me trying! Although it rained so maybe not "real world" atlanta test. Stay tuned on that 1.

I will replace the overflow hose on res with some 1/4 ID line from NAPA. Same with the other line from head to res, it seems to be weeping at the res a bit despite being tight.

It may just be my hopeful outlook, but when you pop the hood with engine running you get blasted with air from the main cooling fan now, whereas before fan clutch replacement never really felt the air much. I also tried to spin fan after 90-100C shut down, it spun maybe a few blades and stopped. Im guessing the fan clutch was def. toast. Not a bad mod, going with 606 clutch. At $98 its much cheaper than $270 for the 603 version...and as mentioned DOESNT require any mods to clutch to use metal fan, and doesnt require plastic 606 fan.

For anyone in question about this job, its not bad. Taking rad out is quite simple and would be really easy if it wasnt for the stupid shroud. I should section it so it can be removed with rad and fan still in. Maybe next time..

The electric fan will come on at 120 and turn the A/C off at 128, depending on which switch you have. I use one from the 201 that is rated at 100 and 110. GSXR uses one rated somewhere in between. I can't remember the exact temps though.

wait thats contrary to what dave has in his pic -

(image from gsxr)

http://www.w124performance.com/image...ch_105-12x.jpg

which is correct?

pricing from Phil as follows :
blue = $33
grey = $47

I think the 105/115 switch is as high as I would go. At 115 I'm turning the A/C off anyway.

Clarification: With either the blue or gray switch shown in my photo above, the electric fan turns on high speed at 105°C (the two poles of the switch are closed, which triggers the relay, which turns the fan on). You can test this by shorting the two wires at the switch with the engine running... the fan should turn on high.

The third, single pole on the switch is for the AC safety... at either 115, 120, or 128°C (depending on the switch part number / color); this second stage will shut off the AC compressor to reduce thermal load on the engine until it cools sufficiently. It would be rather unusual to ever reach this safety net, though, most 603 owners get nervous far before those temps and switch the heater on full!


Paul, if your temp problems are not cured with your recent fixes... my next bet is the radiator. I'll save you the long story, but the PO had changed it on my car (new dealer radiator) not long before I bought it, and only 5 years later it was getting up to 110-115°C in the summer. I changed EVERYTHING else, assuming it couldn't possibly be the almost-new radiator. In desperation, I finally swapped the radiator, and voila... instant cure. The car refused to go *over* 100° after that, even in 110°F ambients (Sacramento summer). On the flip side, my sister's '87 300D has a similar issue, but a new radiator didn't fix hers - that one is still a mystery that we're working on!

:hat:

thanks for clarification. I will replace the 3 pin as Ive never heard high speed fan even a 120C.

its definitely running cooler now. i pushed it pretty hard in traffic yesterday, seems to briefly touch 100C then drop back to 90 ish. will keep watching it though, and i know the rad is long over due, i just dont have the $$$$$$ at the moment. hopefully this will be enough.

#006 545 40 24
 

EDIT: (Through the kind services of GSXR's forum correction)
I must point out BOTH of the below statements are Incorrect!

CORRECTION:
MB # 008 542 45 17 (Blue Two pole SENSOR) operates as low as 107 C.
AND MB # 006 545 40 24 is a SWITCH not a sensor...SO the two are not
interchangeable!


I found it!

Behr /Thermo-Tronik

100 Degrees C "Auxiliary Fan Switch"

Can any body think of a reason not to Swap out the Blue 130 Degree C switch
with this one?
(Hey, I'll buy auxiliary fan motors whenever necessary...TOOOOO Cheap,
when compared with the Aluminum Head on the OM 602.)

AND when combined with the K6JRF "Resistor Enhancement" (2nd picture)the fans will leap to High @ 92 Degrees C.
[Since his RE is "FailSafe" (Reverts to Switch OE settings upon failure)I'll have High fans by 100 Degrees C no matter what.]

The early (to approx 1987) cars use a 3-prong switch that is actually a switch... it closes contacts at a certain temperature.

The late (from approx 1988) cars use a 2-prong sensor which has variable resistance based on temperature. You can adjust the temp lower using JimF's resistor mod. However this WILL NOT work on the early (pre-1988) cars. They have different control systems. You can't swap in the resistive sensor in place of a discrete switch.

:scholar:

That is not the right switch. You want the 3 pin switch for the '87, not the 2 pin. This is the part number, 006 545 4224.

http://www.allpartsexpress.com/searchItem.epc $23.91 at All Parts Express.

http://catalog.peachparts.com/searchitem.epc?cookieID=2NC1EQIJC2NC1F7HLL $49.50 at Fastlane.

If anyone understands the difference in price between the 2 parts shop, please explain it to me.

year(s) model hybrid
 

GSXR and BIO300TDTdriver,

I've got a (2006 MB Re-manufactured engine) of a 1992 602.962 in a 1990 124.128.

So it has the Resistive Sensor (two pole,in the B10/8 position)
I'm going to swap in the 100 Degree C #006 545 40 24 from the 201 Chassis.
With the "JimF" improvement (to lower High Speed Auxiliary Fan Engagement
to 92 C).

Chances are there'll be times the Viscous Fan Clutch cannot pull down the
Temperature quickly enough from it's engagement @ 90 C BACKFLOW from
the RADIATOR's Temperature;AND the Auxiliary Fans will engage along with
the Mechanical Fan MOMENTARILY.

I'm willing to throw Aux Fan Motors(AND Bearings) at the 124.128...
Anything over 99 C gives me the "Willies".So I start getting nervous at 95 C.

EDIT: (Through the kind services of GSXR's forum correction)
I must point out BOTH of the above statements are Incorrect!

CORRECTION:
MB # 008 542 45 17 (Blue Two pole SENSOR) operates as low as 107 C.
AND MB # 006 545 40 24 is a SWITCH not a sensor...SO the two are not
interchangeable!

OK, so you need the 2 pin switch. I should have looked at your sig line. Yeez, you are even more paranoid than I am and I have the OM 603. I only panic at 110. Your OM602 is fine at 105 IMHO.

You cannot replace a sensor with a switch. They are not the same thing, and do not work the same way. I'm not sure how else to explain it... a switch is on or off, based on a certain temperature. A sensor just sends a temperature reading to a computer, and the computer is what decides to turn the fan on or off - you can't change what the computer is programmed to do. Your car already has the resistive sensor. Installing a different sensor WILL NOT change the temperature the fan triggers at. And installing a switch will make it not work at all (or possibly run all the time!). Just do the JimF modification - that's all you need. JimF's mod simply fools the computer into thinking the engine is hotter than it really is, so it turns the fan on sooner.




You need to adjust your nervous system. ;) 110°C is not dangerous, not even for a 603. It simply indicates the cooling system is likely not functioning normally. 95-105°C is perfectly normal in high ambient temperatures (hot summer day, or climbing a steep grade, etc). I don't get nervous until things hit about 115°C or so, which shouldn't happen unless there has been a serious failure of some sort...


:nuke:

Thanks Guys!
 

Jim F's Resistor Enhancement ONLY.