OM603 to OM606 Fan Clutch Mod ???? - Page 2 - PeachParts Mercedes-Benz Forum

a2t · #1 05-07-2009, 02:12 PM

I was able to work on the mule last night and get it all back together.

The 606 fan clutch indeed fits the 603 metal fan. The only difference I saw was the 606 fan clutch has slightly thinner profile, so the fan sits about 1/8” farther away from radiator. No big deal, it still fits in the shroud OK and clears the serp belt and accessories just fine.

FYI, the 9 blade metal fan weighed 840 grams (in case anyone wants to compare to plastic fan weight). The 606 fan clutch weighed 855 grams, and the 603 clutch weighed 940 grams.

I also bought a can of industrial condenser cleaner from Grainger and did what Brian previously instructed. Man that thing was dirty, you couldn’t really see thru it when held up to light. After degreasing it for 2 hrs and spraying out with garden hose for 15 min, it was a lot cleaner, but still has debris in between the coils.

I also installed the new res and coolant level sensor

And tried to install the new lower rad hose but World Pac sent a hose that didn’t fit (just like the upper hose they sent me a year back). Took another hr to dismantle everything to reinstall the old rubber lower rad hose. Not happy bout that… guess I will have to go to dealer and buy 1.

I will drive it for next few weeks and let you know how it does. Its pretty hot today so I should be able to get on it going home from work, see if it hits 120C again…

Oh 1 question – wheres the hose on top of res (at the cap) go to? Mine broke (actually crumbled) when I tried to remove it off old res. I will have to replace, but it looks like it goes toward passenger cabin somewhere? Is is bad to run engine with this disconnected? I had to cut off the end and its sorta/kinda reconnected but too short so I need another 1.

gsxr · #2 05-07-2009, 02:26 PM

Quote:

Originally Posted by a2t

I was able to work on the mule last night and get it all back together. ... After degreasing it for 2 hrs and spraying out with garden hose for 15 min, it was a lot cleaner, but still has debris in between the coils.

Compressed air, and/or a nylon brush, can help to get more debris out of the condenser. If the radiator is removed, perform the same treatment on it as well.

Quote:

Originally Posted by a2t

I also installed the new res and coolant level sensor.

Smart move - the new reservoir has a silica pack to help control corrosion. Make sure you only use MB or Zerez G-05 "yellow" antifreeze when re-filling. In a hot climate where freeze protection isn't critical, use less... maybe only 2-4 quarts of a/f (for a 20%-40% mix). I add the a/f first, plus a full bottle of Water Wetter, then fill up the rest of the way with distilled water. Don't re-start the car until you can feel liquid in the upper radiator hose. If you can't feel liquid up there... the system isn't filled properly.

Quote:

Originally Posted by a2t

And tried to install the new lower rad hose but World Pac sent a hose that didn’t fit (just like the upper hose they sent me a year back). Took another hr to dismantle everything to reinstall the old rubber lower rad hose. Not happy bout that… guess I will have to go to dealer and buy 1.

Some items simply are NOT worth buying aftermarket. My '95 E420 came with aftermarket radiator hoses installed. The upper hose touched the p/s reservoir. I replaced it with a new OE/dealer hose which was curved properly and didn't touch the reservoir. Unfortunately, it's often a trial & error method to determine which items you can buy OEM/aftermarket to save a few bucks, and which items should always be purchased OE/dealer. If you need a lead on buying dealer stuff at wholesale, drop me a line.

Quote:

Originally Posted by a2t

I will drive it for next few weeks and let you know how it does. Its pretty hot today so I should be able to get on it going home from work, see if it hits 120C again…

It better not. BTW, does your electric fan kick on high at 105°C? If not, you really should replace the switch, I used the gray one on my car (click here). If the engine still runs hot (anything over 105°C outside of Death Valley indicates a problem)... how old is the radiator, and how old is the water pump?

Quote:

Originally Posted by a2t

Oh 1 question – wheres the hose on top of res (at the cap) go to? Mine broke (actually crumbled) when I tried to remove it off old res. I will have to replace, but it looks like it goes toward passenger cabin somewhere? Is is bad to run engine with this disconnected? I had to cut off the end and its sorta/kinda reconnected but too short so I need another 1.

That hose goes to the overflow catch tank in the wheel well - if you remove the plastic splash panel inside the fender, you'll see it. When the cooling system gets extremely hot (say, 120°C) the coolant may overflow into this tank. When it cools, it pulls the liquid back into the system. Just find some hose of the proper I.D. and splice it into the existing hose... it should turn soft after it goes through the firewall partition. This is a common problem.

a2t · #3 05-07-2009, 09:19 PM

Quote:

It better not. BTW, does your electric fan kick on high at 105°C? If not, you really should replace the switch, I used the gray one on my car (click here). If the engine still runs hot (anything over 105°C outside of Death Valley indicates a problem)... how old is the radiator, and how old is the water pump?

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..

a2t · #4 05-07-2009, 11:21 PM

Quote:

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)

which is correct?

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

Bio300TDTdriver · #5 05-07-2009, 11:30 PM

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

gsxr · #6 05-08-2009, 10:58 AM

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!

a2t · #7 05-09-2009, 12:21 PM

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.

compress ignite · #8 05-09-2009, 10:49 PM

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.]

a2t · #9 05-11-2009, 07:28 PM

so how do i get "JimF" 's mod on my 87 ?? or am i just F'd?

couple more days driving, it hasnt passed 100C yet. 80-90-100 mph uphill, full throttle, ill keep trying.

you can really HEAR that fan spinning now, sounds like an old chevy blazer. i guess fan speed does make a difference even at hwy speeds.

Bio300TDTdriver · #10 05-11-2009, 11:03 PM

Quote:

Originally Posted by a2t

so how do i get "JimF" 's mod on my 87 ?? or am i just F'd?

couple more days driving, it hasnt passed 100C yet. 80-90-100 mph uphill, full throttle, ill keep trying.

you can really HEAR that fan spinning now, sounds like an old chevy blazer. i guess fan speed does make a difference even at hwy speeds.

100mph uphill and it is not over 100.

You don't need any further mods. Your car will be fine.

gsxr · #11 05-12-2009, 09:46 AM

Quote:

Originally Posted by a2t

so how do i get "JimF" 's mod on my 87 ?? or am i just F'd?

No need, really... just make sure the 3-prong switch is working that triggers the fan at 105°C.

Quote:

Originally Posted by a2t

couple more days driving, it hasnt passed 100C yet. 80-90-100 mph uphill, full throttle, ill keep trying.

Sounds to me like it's fixed!

Quote:

Originally Posted by a2t

you can really HEAR that fan spinning now, sounds like an old chevy blazer.

When engaged, you can tell from outside the car, but not usually inside... unless the metal fan is significantly louder. Perhaps that's one of the benefits of the plastic fan - reduced noise. (?)

Quote:

Originally Posted by a2t

I guess fan speed does make a difference even at hwy speeds.

It absolutely DOES make a difference at freeway speeds! Many people have the misconception that at freeway speeds, the "ram air" effect takes over and the fan isn't required. This is wrong, wrong, wrong... as you have just discovered. I learned the same thing myself back in 1998 when I was chasing down my temp issues, and a new clutch dropped freeway engine temps a solid 5-10°C with no other changes. When the change is this dramatic, the old clutch was likely totally dead, empty of silicone fluid, and just barely freewheeling. You can refill the old clutches, btw, if you really want to save some $$. I fixed two of 'em that way, but the process takes hours.

compu_85 · #12 05-12-2009, 09:51 AM

Quote:

{the fan} absolutely DOES make a difference at freeway speeds! Many people have the misconception that at freeway speeds, the "ram air" effect takes over and the fan isn't required. This is wrong, wrong, wrong...

I noticed the same thing, especially when running the air con! The fan is 100% important to have working under all driving conditions.

-Jason

erizo715 · #13 10-14-2009, 11:45 AM

You can refill the old clutches, btw, if you really want to save some $$. I fixed two of 'em that way, but the process takes hours.

[/QUOTE]
Can you describe the filling procedure please, it`s nice to have a new one of course, but money is tight now a days, if you can spare $100.00 that`s always a welcome present.

a2t · #14 05-12-2009, 09:37 PM

yeah good point, plastic fan is probably quieter. But i lost the under hood mat some time ago so maybe thats it.

Running like a top, AC is too cold (smack me twice for saying that in May...) I gotta spin the temp wheel up to 22-24C to keep from freezing my ass off.

I guess with a dead fan clutch at hwy speeds the fan actually impedes airflow since its not spinning fast enough.

Thanks for all help. I *should* be ready for July...knock on aluminum #14 head.

Now all I gotta do is call worldpac and return this useless lower rad hose and go buy new 1 at dealer. B!tch to install that thing but the one in there is a relic. oh yeah and get a new 3 pin for good measure.

Ether · #15 05-26-2009, 07:07 PM

I installed the 606 fan clutch (thanks Paul!) on my 87 SDL yesterday with no modification required.

Can't say that I notice the fan being louder now but it certainly stops much quicker than the replaced clutch when I turn off the engine so I'm sure I'm getting better air flow. Will need some warmer days here in Atlanta before I can tell if it helps keep my running temp below 100.